螺纹公差等级对照表
常用螺纹尺寸及公差汇总表
公制螺纹基本直径内螺纹公差等级外螺纹公差6H7H6G大径中径小径中径公差小径公差中径公0,差小径公差中径公差小径公差M10*1109.358.9170,+0.1500,+0.2360,+0.1900,+0.300-0.026,-0.138-0.026,0.206M12*11211.3510.9170,+0.1600,+0.2360,+0.2000,+0.300-0.026,-0.144-0.026,0.206M14*11413.35122.9170,+0.1600,+0.2360,+0.2000,+0.300-0.026,-0.144-0.026,0.206M12*1.251211.18810.6470,+0.1800,+0.2650,+0.2240,+0.335-0.028,-0.160-0.028,-0.240 M14*1.251413.18812.6470,+0.1800,+0.2650,+0.2240,+0.335-0.028,-0.160-0.028,-0.240 M12*1.51211.02610.3760,+0.1900,+0.3000,+0.2360,+0.375-0.032,-0.172-0.032,-0.268 M14*1.51413.02612.3760,+0.1900,+0.3000,+0.2360,+0.375-0.032,-0.172-0.032,-0.268 M16*1.51615.02614.3760,+0.1900,+0.3000,+0.2360,+0.375-0.032,-0.172-0.032,-0.268 M18*1.51817.02616.3760,+0.1900,+0.3000,+0.2360,+0.375-0.032,-0.172-0.032,-0.268 M20*1.52019.02618.3760,+0.1900,+0.3000,+0.2360,+0.375-0.032,-0.172-0.032,-0.268 M22*1.52221.02620.3760,+0.1900,+0.3000,+0.2360,+0.375-0.032,-0.172-0.032,-0.268 M24*1.51423.02622.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M26*1.52625.02624.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M27*1.52726.02625.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M30*1.53029.02628.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M33*1.53332.02631.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M36&1.53635.02634.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M39*1.53938.02637.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M42*1.54241.02640.3760,+0.2000,+0.3000,+0.2500,+0.375-0.032,-0.182-0.032,-0.268 M27*22725.70124.8350,+0.2240,+0.3750,+0.2800,+0.475-0.038,-0.208-0.038,-0.318 M30*23028.70127.8350,+0.2240,+0.3750,+0.2800,+0.475-0.038,-0.208-0.038,-0.318 M33*23331.70130.8350,+0.2240,+0.3750,+0.2800,+0.475-0.038,-0.208-0.038,-0.318 M36*23634.70133.8350,+0.2240,+0.3750,+0.2800,+0.475-0.038,-0.208-0.038,-0.318 M39*23937.70136.8350,+0.2240,+0.3750,+0.2800,+0.475-0.038,-0.208-0.038,-0.318 M42*24240.70139.8350,+0.2240,+0.3750,+0.2800,+0.475-0.038,-0.208-0.038,-0.318 M45*24543.70142.8350,+0.2240,+0.3750,+0.2800,+0.475-0.038,-0.208-0.038,-0.318 M52*25250.70149.8350,+0.2360,+0.3750,+0.3000,+0.475-0.038,-0.218-0.038,-0.318 M60*26058.70157.8350,+0.2360,+0.3750,+0.3000,+0.475-0.038,-0.218-0.038,-0.318 M64*26462.70161.8350,+0.2360,+0.3750,+0.3000,+0.475-0.038,-0.218-0.038,-0.318 M72*27270.70169.8350,+0.2360,+0.3750,+0.3000,+0.475-0.038,-0.218-0.038,-0.318美制NPSM螺纹（美国标准ANSI B1.20.1机械连接用直管螺纹60度）外螺纹（2A级）内螺纹（2B级）大径中径小径中径标号螺纹代号最大值最小值最大值最小值最小值最大值最小值最大值021/8-27NPSM 10.0849.9069.4629.3709.0939.2469.4899.609041/4-18NPSM 13.36013.13212.45412.34211.88712.21712.48712.634063/8-18NPSM 16.81516.58615.89015.77615.31615.54515.92616.076081/2-14NPSM 20.90420.65019.73319.60418.97419.27919.77119.942123/4-14NPSM 26.26426.01025.07724.94324.33324.63825.11825.293161-11.5NPSM 32.84232.53731.41731.27030.50530.75931.46031.65320 1.1/4-11.5NPSM 41.60541.30040.17340.02039.26839.49740.21840.41624 1.1/2-11.5NPSM 47.67647.37146.24146.08645.33945.56846.28646.487322-11.5NPSM 59.71559.41158.27858.12057.37957.60758.32658.53240 2.1/2-8NPSM 72.16171.78070.10469.91668.78369.26670.16070.409483-8NPSM 88.06287.68186.00985.81684.68485.16686.06886.319NPT 布锥管螺纹基面上的直径螺纹长度标号螺纹代号大径中径小径管端至基面长有效长度端面大径02Z1/8*2710.2429.4898.736 4.102 6.7039.98604Z1/4*1813.61612.48711.3855.78610.20613.25406Z3/8*1817.05515.92614.7976.09610.35816.67408Z1/2*1421.22319.77218.3218.12813.55620.71512Z3/4*1426.56825.11723.6668.61113.86126.03016Z1*11.533.22831.46129.69410.16017.34332.59320Z1.1/4*1.541.98540.21838.45110.66817.95341.31824Z1.1/2*11.548.05446.28744.52010.66818.37747.38732Z2*11.560.09258.32556.55811.07419.21559.40040Z2.1/2*872.69970.15967.61917.32328.89271.61648Z3*888.60886.06883.52819.45630.48087.39255度英锥管螺纹基本直径内螺纹外螺纹公差等级AB 标号螺纹代号大径中径小径中径公差小径公差中径公差大径公差中径公差大径公差02G1/8*289.7289.1478.5660.170，00.282，00，-0.1700，-0.2140，-0.2140，-0.21404G1/4*1913.15712.30111.4450.125，00.445，00.-0.1250，-0.2500，-0.2500，-0.25006G3/8*1916.66215.80614.9500.125，00.445，00，-0.1250，-0.2500，-0.2500，-0.25008G1/2*1420.95519.79318.6310.142，00.541，00，-0.1420，-0.2840，-0.2840，-0.28410G5/8*1422.91121.74920.5870.142，00.541，00，-0.1420，-0.2840，-0.2840，-0.28412G3/4*1426.44125.27924.1170.142，00.541，00，-0.1420，-0.2840，-0.2840，-0.28416G1*1133.24931.77030.2910.180，00.640，00，-0.1800，-0.3600，-0.3600，-0.36020G1.1/4*1141.91040.43138.9520.180，00.640，00，-0.1800，-0.3600，-0.3600，-0.36024G1.1/2*1147.80346.32444.8450.180，00.640，00，-0.1800，-0.3600，-0.3600，-0.36032G2*1159.61458.13556.6560.180，00.640，00，-0.1800，-0.3600，-0.3600，-0.36040G2.1/2*1175.18473.70572.2260.217，00.640，00，-0.2170，-0.4340，-0.4340，-0.43448G3*1187.88486.40584.9260.217，00.640，00，-0.2170，-0.4340，-0.4340，-0.43455度英锥管螺纹基面上的直径基准长度有效螺纹长度标号螺纹代号大径中径小径基本最大最小基本最大最小圆锥内螺纹基面轴向位移的极限偏差端面大径02R1/8*289.7289.1478.5664 4.9 3.16.57.4 5.61.19.47804R1/4*1913.15712.30111.44567.3 4.79.7118.4 1.712.78206R3/8*1916.66215.80614.950 6.47.7 5.110.111.48.8 1.716.26208R1/2*1420.95519.79318.6318.2106.413.21511.42.320.44312R3/4*1426.44125.27924.1179.511.37.714.516.312.7 2.325.84716R1*1133.24931.77030.29110.412.78.116.819.114.5 2.932.59920R1.1/4*1141.91040.43138.95212.71510.419.121.416.8 2.941.11624R1.1/2*1147.80346.32444.84512.71510.419.121.416.8 2.947.00932R2*1159.61458.13556.65615.918.213.623.425.721.1 2.958.62040R2.1/2*1175.18473.70572.22617.5211426.730.223.2 3.574.09048R3*1187.88486.40584.92620.624.117.129.833.326.3 3.586.597美制螺纹外螺纹内螺纹公差等级2A公差等级2B大径中径小径中径标号螺纹代号最大最小最大最小小径最大最小最大最小最大大径最小JIC 螺纹025/16×24UNF 7.9107.7277.2217.127 6.6506.7827.0367.2497.3717.938033/8*24UNF9.4979.3148.8098.7128.2378.3828.6368.8378.9619.525047/16*20UNF11.07910.87410.25410.1479.5689.72810.03310.28710.42411.113051/2*20UNF12.66712.46111.84111.73211.15611.32811.60811.87512.01712.7069/16*18UNF14.25214.03113.33513.22112.57312.75113.08113.37113.5214.288083/4*16UNF19.01218.77317.98117.85417.1217.32317.67818.01918.18419.05107/8*14UNF22.18421.92321.00620.86920.02520.26920.67621.04621.22422.225121.1/16*12UNF26.94426.65525.5725.42524.42524.68925.14625.61325.80126.988161.5/16*12UNF33.29433.00531.9231.77330.77531.03931.49631.96332.15433.338201.5/8*12UNF41.22940.9439.85539.70538.7138.98939.44639.90140.09441.275241.7/8*12UNF47.57947.2946.20546.05345.0645.33945.79646.25146.44947.625322.1/2*12UNF63.45263.16262.07861.9260.93261.21461.67162.12662.33263.5403812UNF76.15775.86274.77874.61873.63273.91474.37174.82675.03476.218HK1.1/2*10UNF38.05237.72436.40136.23835.02935.35735.89036.44936.66038.100ORFS 螺纹049/16*18UNF14.25214.03113.33513.22112.57312.75113.08113.37113.5214.2880611/16*16UNF17.42717.18816.39616.27415.53515.74816.10416.43116.58917.4630813/16*16UNF20.59920.36119.56819.44418.70718.92319.27919.60619.76620.638101*14UNSF25.35725.09524.17824.03623.19523.44423.82524.22124.40725.4121.3/16*12UN30.11929.8328.75428.59827.627.86428.32128.78828.97930.163161.7/16*12UN36.46736.17735.09334.94333.94734.21434.67135.13835.33136.513201.11/16*12UN42.81742.52741.44341.2940.29740.56441.02141.48841.68642.863242*12UN50.75450.46549.3849.2548.23548.51448.97149.42649.62750.8SAE 螺纹065/8×18UNF 15.83915.61814.92314.80314.16114.35114.68114.95815.1115.875121.1/16*14UNF26.94726.683 25.74325.60824.7424.96825.37525.78325.96126.987其他美制螺纹9/16*16UN14.25214.01313.22113.10112.3612.57312.92913.25613.41114.2887/8*12UN22.18221.89220.80820.66819.66219.93920.39620.85121.03422.2252.1/4*12UN57.10456.81555.7355.57554.58554.86455.32155.77655.97657.15可拆式芯子与套筒连接螺纹外螺纹内螺纹公差等级2B 大径中径小径中径软管编号螺纹代号最大最小最大最小小径最小最大最小最大大径R5-049/32*327.1206.967 6.604 6.523 6.175 6.294 6.472 6.629 6.7367.145R5-0546/127*289.1979.0328.6088.5168.1158.2348.4638.6368.7539.225R5-06107/254*2810.68510.52010.09510.0049.6039.7359.93810.12310.24010.713R5-089/16*2414.25714.07413.56913.47012.99713.13213.38613.59913.72914.288R5-1011/16*2417.43217.24916.74416.64216.17216.30716.56116.77416.90617.463R5-1213/16*2020.59920.39919.77919.66719.34719.25319.55819.81219.98220.638R5-161.1/16*1826.95226.73126.03525.91625.27325.45125.78126.07126.22826.988R5-201.5/16*1833.29933.07832.38232.25831.62031.80132.13132.42132.58133.338R5-241.9/16*1839.64939.42838.73238.60537.97038.15138.48138.77138.93639.688R5-322*1850.76250.54149.84549.71549.08349.27649.60649.88350.05350.8002A-047/16*2011.07910.87410.25410.1479.5689.72810.03310.28710.42411.1132A-069/16*1814.25214.03113.33513.22112.57312.75113.08113.37113.52014.2882A-085/8*1815.83915.61814.92314.80314.16114.35114.68114.95815.11015.8752A-103/4*1819.01418.79318.09817.98117.33617.52617.85618.13318.28519.0502A-127/8*1822.18921.96821.27321.15620.51120.70121.03121.30821.46022.2252A-161.3/16*1630.12429.87029.09328.96428.23228.44828.80429.13129.29930.1632A-201.9/16*1839.64939.42838.73238.60537.97038.15138.48138.77138.93639.688新西兰B09内螺纹标号你螺纹代号大径MIN中径MIN中径MAX小径MIN小径MAX B-090.860in*1421.84420.68320.84119.522NPTF+密封管螺纹标号螺纹代号外螺纹小端中径外螺纹大端中径外螺纹小端大径最小外螺纹小端大径最大外螺纹全牙长度内螺纹大端中径内螺纹小端中径内螺纹大端小径最小内螺纹大端小径最大内螺纹全牙长度21/8-27NPTF9.2339.6529.8719.960 6.7039.4899.0588.7638.851 6.924 41/4-18NPTF12.12612.76413.12813.21510.20612.48711.86211.39811.48610.020 63/8-18NPTF15.54516.19316.54716.63410.35815.92615.28114.83714.92410.330 81/2-14NPTF19.26420.11120.61620.70313.55619.77218.92618.33318.42013.571 123/4-14NPTF24.57925.44525.93126.01813.86125.11724.23923.67823.76814.054 161-11.5NPTF30.82631.91032.47432.56217.34331.46130.41129.72529.81316.787 20 1.1/4-11.5NPTF39.55140.67341.19941.28717.95340.21839.13638.48238.57017.295 24 1.1/2-11.5NPTF45.62146.76947.26947.35718.37746.28745.20744.55144.64017.295 322-11.5NPTF57.63358.83459.28159.36919.21558.32557.21956.58956.67717.701 40 2.1/2-8NPTF69.07670.88271.47671.55928.89370.15968.48167.67667.75926.848 483-8NPTF84.85286.75787.25287.33530.48086.06884.25783.58583.66828.981备注：1.表中外螺纹的完整螺纹长度包括不超过一个螺距长度的倒角2.表中内螺纹的完整螺纹长度不包括在中径线和倒角交线外的锥口孔。
螺纹符号尺寸公差对照表
螺纹代号对照表国外螺纹的代号和标注识别1.英制螺纹(螺纹牙型角 55 度)BSW----英国标准惠氏螺纹(粗牙) BSF --- 英国标准惠氏螺纹(细牙)R----锥管外螺纹(旧代号ZG、KG) RC -- 锥管内螺纹(旧代号ZG、KG)G - 直管螺纹(外螺纹分A、B 两面级,丝锥分 G、G-D)2.美制螺纹（螺纹牙型 60 度）UNC---统一制粗牙螺纹（代替NC）UNF -- 统一制细牙螺纹（代替NF）UNEF---统一制超细牙螺纹UN - 统一制不变螺距螺纹UNS---统一制特殊螺纹NPT -- 美国标准锥管螺纹NPSC---美国标准管接头用直管螺纹NGT -- 气瓶用锥螺纹NPTF---干密封锥管螺纹NPSF -- 干密封燃油直管螺纹NPSM---美国标准机械连接用直管螺纹NPTR - 美国标准导杆采用锥管螺纹NPSL---美国标准管锁紧螺母用直管螺纹NPSH -- 美国标准软管连接用直管螺纹3.其它螺纹SM----缝纫机螺纹PZ --- 气瓶用锥螺纹51－201－气门芯螺纹标注示例55°圆柱管螺纹是非螺纹密封管螺纹，属惠氏螺纹家族。
米制和英寸制国家均广泛采用。
用于输送液体、气体、和安装电线的管接头和管子的连接。
国家标准可查阅 GB/T7307-2001。
完整的标记由螺纹特征代号（G）、螺纹尺寸代号、中径公差等级代号（内螺纹省略不标注，外螺纹代号为A 和B）和旋向代号组成：尺寸代号为 3/4 的A 级、右旋、非密封圆柱外螺纹标注为：G3/4A螺纹中的 3/8、1/2、3/4 标记是指螺纹尺寸的直径，单位是英寸。
行内人通常用“分” 来称呼螺纹尺寸，一寸等于 8 分，1/2 寸就是4 分，以此类推55°圆锥管螺纹是螺纹密封管螺纹，属惠氏螺纹家族。
该系列螺纹在世界上应用广泛，常用于水及煤气管行业。
锥度规定为 1：16.国家标准可查阅 GB/T7306-2000。
完整的标记由螺纹特征代号、螺纹尺寸代号和旋向代号组成：英制密封圆柱内螺纹的特征代号为R P；英制密封圆锥内螺纹的特征代号为R C；英制密封圆锥外螺纹的特征代号为R1（与英制密封圆柱内螺纹配合使用）R2（与英制密封圆锥内螺纹配合使用）尺寸代号为 3/4 的左旋、英制密封圆柱内螺纹：R P3/4－LH英制密封管螺纹有两种配合方式，“柱/锥”和“锥/锥”.两种英制密封管螺纹使用不同的螺纹环规（圆柱螺纹环规和圆锥螺纹环规）和螺纹塞规（基准平面的位置不同，两者基准平面相距半牙）.欧洲国家主要采用“柱/锥”配合螺纹；而欧洲以外国家则主要采用“锥/ 锥”配合螺纹.同一个密封管螺纹件，欧洲国家检验合格的管螺纹，欧洲以外国家检验则可能不合格.国际贸易中一定要注意这种差异否则可能出现废品.1994 年前，ISO 的英制密封管螺纹标准及其量规标准是按“锥/锥”配合体系设计的.我国的英制密封管螺纹产品可以直截进入国际市场.而欧洲国家的管螺纹的管螺纹产品则处于不利的地位.2000 年以后，ISO 的英制密封管螺纹标准及其量规标准是按“柱/锥”配合题系设计的.我国原有的英制密封管螺纹产品进入国际市场就会遇到困难.为此，我国于 2000 年修订了英制密封管螺纹国家标准.将原来的一个螺纹标准变为两个螺纹标准，以此提示设计者要注意两种配合螺纹的不同和正确选用. 日本在 1999 年修定英制密封管螺纹标准时，仍然坚持采用 1994 年前的 ISO 标准.所以， 2000 年以后的国际英制密封管螺纹市场更加复杂，国内厂家要备加小心.英制密封管螺纹有两种配合方式：圆柱内螺纹与圆锥外螺纹组成“柱/锥”配合；圆锥内螺纹与圆锥外螺纹组成“锥/锥”配合. 目前的 ISO 英制密封管螺纹量规标准（ISO 7-2：2000）是按“柱/锥”配合体系设计的. 对密封管螺纹，利用 RP/R1，RC/R2 分别表示“柱/锥” 和“锥/锥”螺纹副。
螺纹符号尺寸公差对照表
螺纹符号尺⼨公差对照表螺纹代号对照表国外螺纹的代号和标注识别1.英制螺纹(螺纹⽛型⾓ 55 度)BSW----英国标准惠⽒螺纹(粗⽛) BSF --- 英国标准惠⽒螺纹(细⽛)R----锥管外螺纹(旧代号ZG、KG) RC -- 锥管内螺纹(旧代号ZG、KG)G - 直管螺纹(外螺纹分A、B 两⾯级,丝锥分 G、G-D)2.美制螺纹（螺纹⽛型 60 度）UNC---统⼀制粗⽛螺纹（代替NC）UNF -- 统⼀制细⽛螺纹（代替NF）UNEF---统⼀制超细⽛螺纹UN - 统⼀制不变螺距螺纹UNS---统⼀制特殊螺纹NPT -- 美国标准锥管螺纹NPSC---美国标准管接头⽤直管螺纹NGT -- ⽓瓶⽤锥螺纹NPTF---⼲密封锥管螺纹NPSF -- ⼲密封燃油直管螺纹NPSM---美国标准机械连接⽤直管螺纹NPTR - 美国标准导杆采⽤锥管螺纹NPSL---美国标准管锁紧螺母⽤直管螺纹NPSH --美国标准软管连接⽤直管螺纹3.其它螺纹SM----缝纫机螺纹PZ --- ⽓瓶⽤锥螺纹51－201－⽓门芯螺纹标注⽰例55°圆柱管螺纹是⾮螺纹密封管螺纹，属惠⽒螺纹家族。
⽶制和英⼨制国家均⼴泛采⽤。
⽤于输送液体、⽓体、和安装电线的管接头和管⼦的连接。
国家标准可查阅 GB/T7307-2001。
完整的标记由螺纹特征代号（G）、螺纹尺⼨代号、中径公差等级代号（内螺纹省略不标注，外螺纹代号为A 和B）和旋向代号组成：尺⼨代号为 3/4 的A 级、右旋、⾮密封圆柱外螺纹标注为：G3/4A螺纹中的 3/8、1/2、3/4 标记是指螺纹尺⼨的直径，单位是英⼨。
⾏内⼈通常⽤“分” 来称呼螺纹尺⼨，⼀⼨等于 8 分，1/2 ⼨就是4 分，以此类推55°圆锥管螺纹是螺纹密封管螺纹，属惠⽒螺纹家族。
该系列螺纹在世界上应⽤⼴泛，常⽤于⽔及煤⽓管⾏业。
锥度规定为1：16.国家标准可查阅 GB/T7306-2000。
螺纹中径对照表
螺纹中径对照表公制螺纹美制NPSM螺纹（美国标准ANSI B1.20.1机械连接用直管螺纹60度）NPT布锥管螺纹标号螺纹代号基面上的直径螺纹长度端面大径大径中径小径管端至基面长有效长度02 Z1/8*27 10.242 9.489 8.736 4.102 6.703 9.986 04 Z1/4*18 13.616 12.487 11.385 5.786 10.206 13.254 06 Z3/8*18 17.055 15.926 14.797 6.096 10.358 16.674 08 Z1/2*14 21.223 19.772 18.321 8.128 13.556 20.715 12 Z3/4*14 26.568 25.117 23.666 8.611 13.861 26.030 16 Z1*11.5 33.228 31.461 29.694 10.160 17.343 32.593 20 Z1.1/4*1.5 41.985 40.218 38.451 10.668 17.953 41.318 24 Z1.1/2*11.5 48.054 46.287 44.520 10.668 18.377 47.38732 Z2*11.5 60.092 58.325 56.558 11.074 19.215 59.400 40 Z2.1/2*8 72.699 70.159 67.619 17.323 28.892 71.616 48 Z3*8 88.608 86.068 83.528 19.456 30.480 87.39255度英锥管螺纹55度英锥管螺纹美制螺纹可拆式芯子与套筒连接螺纹新西兰B09内螺纹标号你螺纹代号大径MIN中径MIN中径MAX小径MIN小径MAXB-09 0.860in*14 21.844 20.683 20.841 19.522NPTF+密封管螺纹备注：1.表中外螺纹的完整螺纹长度包括不超过一个螺距长度的倒角2.表中内螺纹的完整螺纹长度不包括在中径线和倒角交线外的锥口孔。
常用螺纹尺寸及公差汇总表
1.11/16*12UN
24
2*12UN
SAE螺纹
06
5/8×18UNF
12
1.1/16*14UNF
其他美制螺纹
9/16*16UN
7/8*12UN
2.1/4*12UN
可拆式芯子与套筒连接螺纹
软管编号
螺纹代号
外螺纹
内螺纹
公差品级2B
年夜径
中径
小径
小径
中径
年夜径
最年夜
最小
最年夜
最小
最小
最年夜
最小
最年夜
最年夜值
02
1/8-27NPSM
04
1/4-18NPSM
06
3/8-18NPSM
08
1/2-14NPSM
12
3/4-14NPSM
16
20
24
32
40
48
3-8NPSM
NPT布锥管螺纹
标号
螺纹代号
基面上的直径
螺纹长度
端面年夜径
年夜径
中径
小径
管端至基面长有效长度Βιβλιοθήκη 02Z1/8*27
04
Z1/4*18
06
Z3/8*18
06
G3/8*19
0.125, 0
0.445, 0
08
G1/2*14
0.142, 0
0.541, 0
10
G5/8*14
0.142, 0
0.541, 0
12
G3/4*14
0.142, 0
0.541, 0
16
G1*11
0.180, 0
0.640, 0
20
螺纹符号尺寸公差对照表
如 M10、M16 等；细牙普通螺纹用螺纹代号（M）和公称直径×螺距表示，如 M10×1、
M20×1.5 等。完整的螺纹标记是由螺纹特征代号和公差带代号及旋合长度代号组成的，如
M20×1.5-6g-S。M：螺纹代号；20：公称直径；1.5：螺纹导程；6g：公差带等级；S： 旋合长度（中等旋合长度不标注）。
5H/6H/7H
最小
3.242 4.134 4.917 6.647 8.917 8.647 8.376 10.376 10.106 12.376 11.835 14.376 13.835 16.376 15.294 18.375 17.294
推荐麻花 钻直径
3.3 4.2 5 6.8 9 8.8 8.5 10.5 10.2 12.5 12 14.5 14 16.5 15.5 18.5 17.5
英制密封管螺纹有两种配合方式：圆柱内螺纹与圆锥外螺纹组成“柱/锥”配合；圆锥内 螺纹与圆锥外螺纹组成“锥/锥”配合. 目前的 ISO 英制密封管螺纹量规标准（ISO 7-2： 2000）是按“柱/锥”配合体系设计的. 对密封管螺纹，利用 RP/R1，RC/R2 分别表示“柱 /锥” 和“锥/锥”螺纹副。
基本偏差用于特殊场合，如较厚的镀层，一般很少用。
2、g 常用来镀 6-9um 的薄镀层，如产品图纸要求是 6h 的螺栓，其镀前螺纹采用 6g
的公差带。
3、螺纹配合最好组合成 H/g、H/h 或 G/h，对于螺栓、螺母等精制紧固件螺纹，标
准 推荐采用 6H/6g 的配合。
4/8
基本大径/mm ＞≤ 2.8 5.6 5.6 11.2
-180
6G
+293
+28
6e
-63
英制螺纹尺寸公差表
英制螺纹尺寸公差表单位：毫米规格代号系列代号等级螺距外螺纹内螺纹名义直径每英寸牙数外径中径内径小径中径大径1 0.060—80 （0#—80）UNF2 0.3175 1.5113 –0.08128 1.30556 –0.04572 1.12268 1.1811+0.12446 1.3182 +0.05842 1.5243 0.3175 1.5240 –0.08128 1.3182 –0.03302 1.13538 1.1811 +0.12446 1.3182 +0.04318 1.5242 0.073—64 （1#—64）UNC 2 0.396875 1.83896 –0.09652 1.58242 –0.0508 1.35128 1.42494+0.15748 1.59766 +0.06604 1.8542 3 0.396875 1.8542 –0.09652 1.59766 –0.0381 1.36652 1.42494+0.15748 1.59766 +0.04826 1.85423 0.073—72 （1#—72）UNF 2 0.352777 1.83896 –0.0889 1.61036 –0.04826 1.40716 1.4732 +0.1397 1.6256 +0.0635 1.85423 0.352777 1.8542 –0.0889 1.6256 –0.03556 1.4224 1.4732 +0.1397 1.6256 +0.04826 1.85424 0.086—56 （2#—56）UNC 2 0.453571 2.16916 –0.10414 1.87452 –0.05334 1.6129 1.69418 +0.1778 1.88976 +0.07112 2.18443 0.453571 2.1844 –0.10414 1.88976 –0.04064 1.62814 1.69418 +0.1778 1.88976 +0.05334 2.18445 0.086—64 （2#—64）UNF 2 0.396875 2.16916 –0.09652 1.91262 –0.0508 1.68148 1.75514 +0.15748 1.92786 +0.06858 2.18443 0.396875 2.1844 –0.09652 1.92786 –0.0381 1.69672 1.75514 +0.15748 1.92786 +0.0508 2.18446 0.099—48 （3#—48）UNC 2 0.529166 2.49682 –0.1143 2.15392 –0.05842 1.84658 1.94056 +0.20574 2.1717 +0.07620 2.51463 0.529166 2.5146 –0.1143 2.1717 –0.04318 1.86436 1.94056 +0.20574 2.1717 +0.05588 2.51467 0.099—56 （3#—56）UNF 2 0.453571 2.49682 –0.10414 2.20218 –0.05588 1.94056 2.02438 +0.17272 2.21996 +0.07112 2.51463 0.453571 2.5146 –0.10414 2.21996 –0.04064 1.95834 2.02438 +0.17272 2.21996 +0.05334 2.51468 0.112—40 （4#—40）UNC 2 0.635 2.82448 –0.12954 2.413 –0.0635 2.0447 2.15646 +0.2286 2.43332 +0.08382 2.84483 0.635 2.8448 –0.12954 2.43332 –0.04826 2.06502 2.15646 +0.2286 2.43332 +0.06096 2.84489 0.112—48 （4#—48）UNF 2 0.529166 2.82702 –0.1143 2.48412 –0.06096 2.17678 2.27076 +0.18796 2.5019 +0.07874 2.84483 0.529166 2.8448 –0.1143 2.5019 –0.04572 2.19456 2.27076 +0.18796 2.5019 +0.05842 2.844810 0.125—40 （5#—40）UNC 2 0.635 3.15468 –0.12954 2.7432 –0.06604 2.3749 2.48666 +0.21082 2.76352 +0.08382 3.1753 0.635 3.175 –0.12954 2.76352 –0.04826 2.39522 2.48666 +0.21082 2.76352 +0.0635 3.17511 0.125—44 （5#—44）UNF 2 0.577273 3.15722 –0.12192 2.7813 –0.0635 2.44856 2.55016 +0.1905 2.79908 +0.08128 3.1753 0.577273 3.175 –0.12192 2.79908 –0.04826 2.46634 2.55016 +0.1905 2.79908 +0.06096 3.17512 0.138—32 （6#—32）UNC 2 0.79375 3.48488 –0.1524 2.96926 –0.07112 2.51206 2.6416+0.254 2.98958 +0.09398 3.50523 0.79375 3.5052 –0.1524 2.98958 –0.05334 2.53238 2.6416+0.254 2.98958 +0.06858 3.505213 0.138—40 （6#—40）UNF 2 0.635 3.48488 –0.12954 3.0734 –0.06604 2.7051 2.8194+0.2032 3.09372 +0.08636 3.50523 0.635 3.5052 –0.12954 3.09372 –0.0508 2.72542 2.8194 +0.19304 3.09372 +0.0635 3.5052序号 规格代号系列 代号 等级 螺距 外螺纹 内螺纹 名义直径 每英寸牙数外径 中径 内径 小径 中径 大径 14 0.164—32 （8#—32）UNC 2 0.79375 4.14274 –0.1524 3.62712 –0.07366 3.16992 3.302 +0.2286 3.64998 +0.09652 4.1656 3 0.79375 4.1656 –0.1524 3.64998 –0.05588 3.19278 3.302 +0.22606 3.64998 +0.07112 4.1656 15 0.164—36 （8#—36）UNF 2 0.70555 4.14528 –0.1397 3.68808 –0.07112 3.27914 3.4036 +0.2032 3.7084 +0.09144 4.1656 3 0.70555 4.1656 –0.1397 3.7084 –0.05334 3.29946 3.4036 +0.19304 3.7084 +0.06858 4.1656 16 0.190—24 （10#—24）UNC 2 1.05833 4.8006 –0.18288 4.11226 –0.08382 3.50266 3.683 +0.2794 4.13766 +0.10922 4.826 3 1.05833 4.826 –0.18288 4.13766 –0.0635 3.52806 3.683 +0.2667 4.13766 +0.08128 4.826 17 0.190—32（10#—32）UNF 2 0.79375 4.80314 –0.1524 4.28752 –0.0762 3.83032 3.9624 +0.20324.31038 +0.09906 4.826 3 0.79375 4.826 –0.1524 4.31038 –0.05842 3.85318 3.9624 +0.205744.31038 +0.07366 4.826 18 0.216—24 UNC 2 1.058335.461 –0.18288 4.77266 –0.08636 4.16306 4.3434 +0.2544.79806 +0.111765.4864 3 1.05833 5.4864 –0.18288 4.79806 –0.06604 4.18846 4.3434 +0.246384.79806 +0.83825.4864 19 0.216—28 UNF 2 0.90714 5.461 –0.1651 4.87172 –0.08128 4.34848 4.4958 +0.22864.89712 +0.106685.4864 3 0.90714 5.4864 –0.1651 4.89712 –0.06096 4.37388 4.4958 +0.220984.89712 +0.078745.4864 20 0.216—32 UNEF 2 0.79375 5.46354 –0.1524 4.94792 –0.07874 4.49072 4.6228 +0.20324.97078 +0.104145.4864 3 0.79375 5.4864 –0.1524 4.97078 –0.06096 4.51358 4.6228 +0.19054.97078 +0.078745.4864 21 0.250—20 1/4—20 UNC 1 1.276.32206 –0.30988 5.49656 –0.14224 4.76504 4.9784 +0.27945.5245 +0.185426.35 2 1.27 6.32206 –0.20574 5.49656 –0.09398 4.76504 4.9784 +0.27945.5245 +0.124466.35 3 1.27 6.35 –0.20574 5.5245 –0.07112 4.79298 4.9784 +0.271785.5245 +0.091446.35 22 0.250—28 1/4—28UNF 1 0.90714 6.3246 –0.24892 5.73532 –0.127 5.21208 5.3594 +0.22865.76072 +0.16516.35 2 0.90714 6.3246 –0.1651 5.73532 –0.08382 5.21208 5.3594 +0.22865.76072 +0.109226.35 3 0.90714 6.35 –0.1651 5.76072 –0.0635 5.23748 5.3594 +0.20325.76072 +0.081286.35 23 0.250—32 1/4—32UNEF 2 0.79375 6.3246 –0.1524 5.80898 –0.8128 5.35178 5.4864 +0.20325.83438 +0.106686.35 3 0.79375 6.35 –0.1524 5.83438 –0.6096 5.37718 5.4864 +0.175265.83438 +0.078746.35 24 .3125－18 5/16－18UNC 1 1.411117.90702 –0.33274 6.99008 –0.15494 6.17474 6.4008 +0.33027.02056 +0.200667.9375 2 1.411117.90702 –0.22098 6.99008 –0.1016 6.17474 6.4008 +0.33027.02056 +0.134627.9375 3 1.411117.9375 –0.220987.02056 –0.0762 6.20522 6.4008 +0.27947.02056 +0.099067.9375序号 规格代号系列 代号 等级 螺距 外螺纹 内螺纹 名义直径 每英寸牙数外径 中径 内径 小径 中径 大径 25 .3125—20 5/16—20UN 21.27 7.90702 –0.205747.08152 –0.1016 6.35 6.5532 +0.30487.112 +0.132087.9375 31.27 7.9375 –0.205747.112 –0.0762 6.38048 6.5532 +0.2547.112 +0.099067.9375 26 .3125—24 5/16—24UNF 11.0583337.90956 –0.274327.22122 –0.1397 6.61162 6.7818 +0.2547.24916 +0.180347.9375 21.0583337.90956 –0.182887.22122 –0.09398 6.61162 6.7818 +0.2547.24916 +0.121927.9375 31.0583337.9375 –0.182887.24916 –0.6858 6.63956 6.7818 +0.21336 7.24916 +0.091447.9375 27 .3125—28 5/16—28UN 20.90714 7.9121 –0.16517.32282 –0.8636 6.79958 6.9596 +0.20327.34822 +0.111767.9375 30.90714 7.9375 –0.16517.34822 –0.06604 6.82498 6.9596 +0.17018 7.34822 +0.083827.9375 28 .3125—32 5/16—32UNEF 20.79375 7.9121 –0.15247.39648 –0.08128 6.93928 7.0866 +0.17787.42188 +0.106687.9375 30.79375 7.9375 –0.15247.42188 –0.06096 6.96468 7.0866 +0.14478 7.42188 +0.78747.9375 29 0.375—16 3/8—16 UNC 11.5875 9.49198 –0.360688.46074 –0.1651 7.5438 7.7978 +0.35568.49376 +0.21599.525 21.5875 9.49198 –0.238768.46074 –0.11176 7.5438 7.7978 +0.35568.49376 +0.144789.525 31.5875 9.525 –0.238768.49376 –0.08382 7.57682 7.7978 +0.28448 8.49376 +0.109229.525 30 0.375—20 3/8—20UN 21.27 9.49452 –0.205748.66902 –0.10414 7.9375 8.1534 +0.27948.6995 +0.137169.525 31.27 9.525 –0.205748.6995 –0.07874 7.96798 8.1534 +0.22098 8.6995 +0.10169.525 31 0.375—24 3/8—24UNF 11.0583339.49706 –0.274328.80872 –0.14478 8.19912 8.382 +0.2548.83666 +0.18796 9.525 21.0583339.49706 –0.182888.80872 –0.09652 8.19912 8.382 +0.2548.83666 +0.12466 9.525 31.0583339.525 –0.182888.83666 –0.07366 8.22706 8.382 +0.182888.83666 +0.09398 9.525 32 0.375—28 3/8—28UN 20.90714 9.49706 –0.16518.90778 –0.09144 8.38454 8.5344 +0.22868.93572 +0.116849.525 30.90714 9.525 –0.16518.93572 –0.06858 8.41248 8.5344 +0.16764 8.93572 +0.08899.525 33 0.375—32 3/8—32UNEF 20.79375 9.4996 –0.15248.98398 –0.08636 8.52678 8.6614 +0.20329.00938 +0.111769.525 30.79375 9.525 –0.15249.00938 –0.0635 8.55218 8.6614 +0.14986 9.00938 +0.083829.525 34 0.4375—14 UNC 11.81428611.07694 –0.39379.89838 –0.18034 8.8519 9.144 +0.40649.93394 +0.2336811.1125 2 1.81428611.07694 –0.261629.89838 –0.11938 8.8519 9.144 +0.40649.93394 +0.1549411.1125 3 1.81428611.1125 –0.261629.93394 –0.0889 8.88746 9.144 +0.297189.93394 +0.1168411.1125 35 0.4375—16 UN 2 1.5875 11.07694 –0.2387610.0457 –0.11684 9.12876 9.398 +0.355610.08126 +0.1498611.1125 3 1.5875 11.1125 –0.2387610.08126 –0.08636 9.16432 9.398 +0.25410.08126 +0.114311.1125号 代号 级名义直径 每英寸牙数 外径 中径 内径 小径 中径 大径 36 0.4375—20 UNF 11.27 11.07948 –0.3098810.25398 –0.160029.52246 9.7282 +0.304810.287 +0.2057411.1125 2 1.27 11.07948 –0.2057410.25398 –0.106689.52246 9.7282 +0.304810.287 +0.1371611.1125 3 1.27 11.1125 –0.2057410.287 –0.078749.55548 9.7282 +0.21844 10.287 +0.1041411.1125 37 0.4375—28 UNEF 2 0.90714311.08456 –0.165110.49528 –0.091449.97204 10.1346 +0.203210.52322 +0.1168411.1125 3 0.90714311.1125 –0.165110.52322 –0.068589.99998 10.1346 +0.154910.52322 +0.0889 11.1125 38 0.4375—32 UN 2 0.79375 11.0871 –0.152410.57148 –0.0863610.11248 10.2616 +0.177810.59688 +0.1117611.1125 3 0.79375 11.1125 –0.152410.59688 –0.0635 10.1396810.2616 +0.137210.59688 +0.0838211.1125 39 0.500—13 UNC 1 1.95384612.6619 –0.4140211.3919 –0.1879610.2641410.5918 +0.431811.43 +0.2463812.7 2 1.95384612.6619 –0.2768611.3919 –0.12710.2641410.5918 +0.431811.43 +0.165112.7 3 1.95384612.700 –0.2768611.43 –0.0939810.3022410.5918 +0.289611.43 +0.1219212.7 40 0.500—16 UN 2 1.5875 12.66444 –0.2387611.6332 –0.1193810.7162610.9728 +0.355611.66876 +0.1549412.7 3 1.5875 12.700 –0.2387611.66876 –0.088910.7518210.9728 +0.251511.66876 +0.1168412.7 41 0.500—20 UNF 1 1.27 12.66698 –0.3098811.84148 –0.1625611.10996 11.3284 +0.431811.8745 +0.2133612.7 2 1.27 12.66698 –0.2057411.84148 –0.1092211.10996 11.3284 +0.431811.8745 +0.1422412.7 3 1.27 12.700 –0.2057411.8745 –0.0812811.14298 11.3284 +0.195611.8745 +0.1066812.7 42 0.500—28 UNEF 2 0.90714312.67206 –0.165112.08278 –0.0939811.55954 11.7094 +0.228612.11072 +0.1219212.7 3 0.90714312.700 –0.165112.11072 –0.0711211.58748 11.7094 +0.167612.11072 +0.0914412.7 43 0.500—32 UN 2 0.79375 12.6746 –0.152412.15898 –0.0889 11.70178 11.8364 +0.203212.18438 +0.114312.7 3 0.79375 12.700 –0.152412.18438 –0.0660411.72718 11.8364 +0.149812.18438 +0.0863612.7 44 0.5625—12 UNC 1 2.11666714.24686 –0.4368812.87272 –0.1981211.65098 11.9888 +0.457212.91336 +0.2590814.2875 2 2.11666714.24686 –0.2895612.87272 –0.1320811.65098 11.9888 +0.457212.91336 +0.1727214.2875 3 2.11666714.2875 –0.2895612.91336 –0.0990611.70178 11.9888 +0.312412.91336 +0.1295414.2875 45 0.5625—16 UN 2 1.5875 14.25194 –0.2387613.2207 –0.1193812.3037612.573 +0.355613.25626 +0.1549414.2875 3 1.5875 14.2875 –0.2387613.25626 –0.0889 12.3393212.573 +0.228613.25626 +0.1168414.2875号 代号 级名义直径 每英寸牙数 外径 中径 内径 小径 中径 大径 46 0.5625—18 UNF 11.41111 14.25194 –0.3327413.335 –0.17272 12.5196612.7508 +0.330213.37056 +0.2260614.2875 2 1.41111 14.25194 –0.2209813.335 –0.1143 12.5196612.7508 +0.330213.37056 +0.1498614.2875 3 1.41111 14.2875 –0.2209813.37056 –0.8636 12.5552212.7508 +0.218413.37056 +0.1117614.2875 47 0.5625—20 UN 2 1.27 14.25448 –0.2057413.42898 –0.10668 12.6974612.9032 +0.304813.462 +0.139714.2875 3 1.27 14.2875 –0.2057413.462 –0.08128 12.7304812.9032 +0.208313.462 +0.1041414.2875 48 0.5625—24 UNEF 2 1.05833 14.25702 –0.1828813.56868 –0.09906 12.9590813.1318 +0.25413.59916 +0.1295414.2875 3 1.05833 1402875 –0.1828813.59916 –0.07366 12.9895613.1318 +0.187913.59916 +0.0965214.2875 49 0.5625—28 UN 2 0.90714 14.25956 –0.165113.67028 –0.09398 13.1470413.3096 +0.203213.69822 +0.1168414.2875 3 0.90714 14.2875 –0.165113.69822 –0.07112 13.1749813.3096 +0.154913.69822 +0.0914414.2875 50 0.5625—32 UN 2 0.79375 14.2621 –0.152413.74648 –0.0889 13.2892813.4366 +0.177813.77188 +0.114314.2875 3 0.79375 14.2875 –0.152413.77188 –0.06604 13.3146813.4366 +0.137213.77188 +0.0863614.2875 51 0.625—11 UNC 1 2.30909 15.83436 –0.4622814.33576 –0.21082 13.0022613.3858 +0.482614.3764 +0.2717815.875 2 2.30909 15.83436 –0.3073414.33576 –0.1397 13.0022613.3858 +0.482614.3764 +0.1828815.875 3 2.30909 15.875 –0.3073414.3764 –0.10414 13.0429 13.3858 +0.307314.3764 +0.1371615.875 52 0.625—12 UN 2 2.11666715.83436 –0.2895614.46022 –0.13716 12.9844813.589 +0.457214.50086 +0.1803415.875 3 2.11666715.875 –0.2895614.50086 –0.10414 13.2791213.589 +0.2870214.50086 +0.1346215.875 53 0.625—16 UN 2 1.5875 15.83944 –0.2387614.8082 –0.12192 13.8912614.1478 +0.355614.84376 +0.1574815.875 3 1.5875 15.875 –0.2387614.84376 –0.09144 13.9268214.1478 +0.233714.84376 +0.1168415.875 54 0.625—18 UNF 1 1.41111115.83944 –0.3327414.9225 –0.1778 14.1071614.351 +0.330214.95806 +0.2311415.875 2 1.41111115.83944 –0.2209814.9225 –0.11938 14.1071614.351 +0.330214.95806 +0.152415.875 3 1.41111115.875 –0.2209814.95806 –0.0889 14.1427214.351 +0.203214.95806 +0.114315.875 55 0.625—20 UN 2 1.27 15.84198 –0.2057415.01648 –0.10922 14.2849614.5034 +0.279415.0495 +0.1422415.875 3 1.27 15.875 –0.2057415.0495 –0.08128 14.3179814.5034 +0.195615.0495 +0.1066815.875 56 0.625—24 UNEF 2 1.05833 15.84452 –0.1828815.15618 –0.1016 14.5465814.732 +0.25415.18666 +0.1320815.875 3 1.05833 15.875 –0.1828815.18666 –0.0762 14.5770614.732 +0.1752615.18666 +0.0990615.875序号 规格代号系列 代号 等级 螺距 外螺纹内螺纹 名义直径 每英寸牙数 外径中径 内径 小径 中径 大径 57 0.625—28 UN 2 0.90714315.84706 –0.165115.25778 –0.09652 14.7345414.8844 +0.228615.28572 +0.1244615.875 3 0.90714315.875 –0.165115.28572 –0.0711214.7624814.8844 +0.167615.28572 +0.0939815.875 58 0.625—32 UN 2 0.79375 15.84706 –0.152415.33144 –0.0914414.8742415.0114 +0.203215.35938 +0.1168415.875 3 0.79375 15.875 –0.152415.35938 –0.0685814.9021815.0114 +0.149915.35938 +0.088915.875 59 0.6875—12 UN 2 2.11667 17.42186 –0.2895616.04772 –0.1371614.8259815.1638 +0.457216.08836 +0.1803417.4625 3 2.11667 17.4625 –0.2895616.08836 –0.1041414.8666215.1638 +0.292116.08836 +0.1346217.4625 60 0.6875—16 UN 2 1.5875 17.42694 –0.2387616.3957 –0.12192 15.4787615.748 +0.355616.43126 +0.1574817.4625 3 1.5875 17.4625 –0.2387616.43126 –0.0914415.5143215.748 +0.21336 16.43126 +0.1168417.4625 61 0.6875—20 UN 2 1.27 17.42948 –0.2057416.60398 –0.1092 15.8724616.0782 +0.304816.637 +0.1422417.4625 3 1.27 17.4625 –0.2057416.637 –0.08128 15.9054816.0782 +0.208316.637 +0.1066817.4625 62 0.6875—24 UNEF 2 1.05833317.43202 –0.1828816.74368 –0.1016 16.1340816.3068 +0.25416.77416 +0.1320817.4625 3 1.05833317.4625 –0.1828816.77416 –0.0762 16.1645616.3068 +0.188016.77416 +0.0990617.4625 63 0.6875—28 UN 2 0.90714317.43456 –0.165116.84528 –0.09652 16.3220416.4846 +0.203216.87322 +0.1246617.4625 3 0.90714317.4625 –0.165116.87322 –0.07112 16.3499816.4846 +0.154916.87322 +0.0939817.4625 64 0.6875—32 UN 2 0.79375 17.43456 –0.152416.91894 –0.09144 16.4617416.6116 +0.177816.94688 +0.1168417.4625 3 0.79375 17.4625 –0.152416.94688 –0.06858 16.4896816.6116 +0.137216.94688 +0.088917.4625 65 0.750—10 UNC 1 2.54 19.00428 –0.4927617.35328 –0.22352 15.8877 16.3068 +0.533417.399 +0.292119.05 2 2.54 19.00428 –0.3276617.35328 –0.14986 15.8877 16.3068 +0.533417.399 +0.1955819.05 3 2.54 19.05 –0.3276617.399 –0.11176 15.9334216.3068 +0.317517.399 +0.1447819.05 66 0.750—12 UN 2 2.11666719.00682 –0.2895617.63268 –0.1397 16.4109416.764 +0.457217.67586 +0.1828819.05 3 2.11666719.05 –0.2895617.67586 –0.10414 16.4541216.764 +0.27178 17.67586 +0.1371619.05 67 0.750—16 UNF 1 1.5875 19.0119 –0.3606817.98066 –0.1905 17.0637217.3228 +0.355618.01876 +0.2489219.05 2 1.5875 19.0119 –0.2387617.98066 –0.127 17.0637217.3228 +0.355618.01876 +0.165119.05 3 1.5875 19.05 –0.2387618.01876 –0.09652 17.1018217.3228 +0.223518.01876 +0.1244619.05 68 0.750—20 UNEF 2 1.27 19.01698 –0.2057418.19148 –0.11176 17.4599617.6784 +0.279418.2245 +0.1447819.05 3 1.27 19.05 –0.2057418.2245 –0.08382 17.4929817.6784 +0.195618.2245 +0.1092219.05序号 规格代号系列 代号 等级 螺距 外螺纹内螺纹 名义直径 每英寸牙数 外径中径 内径 小径 中径 大径 69 0.750—28 UN 2 0.90714319.0195 –0.165118.43024 –0.09652 17.907 18.0594 +0.228618.46072 +0.127 19.05 3 0.90714319.05 –0.165118.46072 –0.0736617.9374818.0594 +0.167618.46072 +0.0939819.05 70 0.750—32 UN 2 0.79375 19.02206 –0.152418.50644 –0.0914418.0492418.1864 +0.203218.53438 +0.1193819.05 3 0.79375 19.05 –0.152418.53438 –0.0685818.0771818.1864 +0.149918.53438 +0.0914419.05 71 0.8125—12 UN 2 2.11666720.59432 –0.2895619.22018 –0.1397 17.9984418.3388 +0.457219.26336 +0.1828820.6375 3 2.11666720.6375 –0.2895619.26336 –0.1041418.0416218.3388 +0.276919.26336 +0.1371620.6375 72 0.8125—16 UN 2 1.5875 20.5994 –0.2387619.56816 –0.1244618.6512218.923 +0.355619.60626 +0.1600220.6375 3 1.5875 20.6375 –0.2387619.60626 –0.0914418.6893218.923 +0.21082 19.60626 +0.1193820.6375 73 0.8125—20 UNEF 2 1.27 20.60448 –0.2057419.77898 –0.1117619.0474619.2532 +0.304819.812 +0.1447820.6375 3 1.27 20.6375 –0.2057419.812 –0.8382 19.0804819.2532 +0.208319.812 +0.1092220.6375 74 0.8125—28 UN 2 0.90714320.607 –0.165120.01774 –0.0965219.4945 19.6596 +0.203220.04822 +0.12720.6375 3 0.90714320.6375 –0.165120.04822 –0.0736619.5249819.6596 +0.154920.04822 +0.0939820.6375 75 0.8125—32 UN 2 0.79375 20.60956 –0.152420.09394 –0.0914419.6367419.7866 +0.177820.12188 +0.1193820.6375 3 0.79375 20.6375 –0.152420.12188 –0.0685819.6646819.7866 +0.137220.12188 +0.0914420.6375 76 0.875—9 UNC 1 2.82222222.17674 –0.5283220.34286 –0.2413 18.7147219.177 +0.5842 20.39112 +0.3124222.225 2 2.82222222.17674 –0.3530620.34286 –0.1600218.7147219.177 +0.5842 20.39112 +0.2082822.225 3 2.82222222.225 –0.3530620.39112 –0.1193818.7629819.177 +0.33274 20.39112 +0.1549422.225 77 0.875—12 UN 2 2.11666722.18182 –0.2895620.80768 –0.1397 19.5859419.939 +0.457220.85086 +0.1828822.225 3 2.11666722.225 –0.2895620.85086 –0.10414 19.6291219.939 +0.2590820.85086 +0.1371622.225 78 0.875—14 UNF 1 1.81428622.18436 –0.393721.0058 –0.20574 19.9593220.2692 +0.406421.04644 +0.2692422.225 2 1.81428622.18436 –0.2616221.0058 –0.13716 19.9593220.2692 +0.406421.04644 +0.177822.225 3 1.81428622.225 –0.2616221.04644 –0.10414 19.9999620.2692 +0.223521.04644 +0.1346222.225 79 0.875—16 UN 2 1.5875 22.1869 –0.2387621.15566 –0.12446 20.2387220.4978 +0.355621.19376 +0.1600222.225 3 1.5875 22.225 –0.2387621.19376 –0.09144 20.2768220.4978 +0.223521.19376 +0.1193822.225 80 0.875—20 UNEF 2 1.27 22.19198 –0.2057421.36648 –0.11176 20.6349620.8534 +0.279421.3995 +0.1447822.225 3 1.27 22.225 –0.2057421.3995 –0.08382 20.6679820.8534 +0.195621.3995 +0.1092222.225。
螺纹中径对照表
螺纹中径对照表公制螺纹美制NPSM螺纹（美国标准ANSI B1.20.1机械连接用直管螺纹60度）NPT布锥管螺纹标号螺纹代号基面上的直径螺纹长度端面大径大径中径小径管端至基面长有效长度02 Z1/8*27 10.242 9.489 8.736 4.102 6.703 9.986 04 Z1/4*18 13.616 12.487 11.385 5.786 10.206 13.254 06 Z3/8*18 17.055 15.926 14.797 6.096 10.358 16.674 08 Z1/2*14 21.223 19.772 18.321 8.128 13.556 20.715 12 Z3/4*14 26.568 25.117 23.666 8.611 13.861 26.030 16 Z1*11.5 33.228 31.461 29.694 10.160 17.343 32.593 20 Z1.1/4*1.5 41.985 40.218 38.451 10.668 17.953 41.318 24 Z1.1/2*11.5 48.054 46.287 44.520 10.668 18.377 47.38732 Z2*11.5 60.092 58.325 56.558 11.074 19.215 59.400 40 Z2.1/2*8 72.699 70.159 67.619 17.323 28.892 71.616 48 Z3*8 88.608 86.068 83.528 19.456 30.480 87.39255度英锥管螺纹55度英锥管螺纹美制螺纹可拆式芯子与套筒连接螺纹新西兰B09内螺纹标号你螺纹代号大径MIN中径MIN中径MAX小径MIN小径MAXB-09 0.860in*14 21.844 20.683 20.841 19.522NPTF+密封管螺纹备注：1.表中外螺纹的完整螺纹长度包括不超过一个螺距长度的倒角2.表中内螺纹的完整螺纹长度不包括在中径线和倒角交线外的锥口孔。
螺纹中径公差等级大全对照表
对于一般紧固件及管接头等通用件有广泛应用。
注意，以上表格中的数值仅供参考，实际应用中可能因具体使用环境和技术需求而有所不同。在实际操作时，建议参考相关行业标准和规范进行准确测量和计算。
+-5.76 ~ +-35.5(公称直径< Φ1.6mm为±1.28~±2.4μm)
中等精度，广泛用于各种机械零件制造。
IT6
+-2.4 - +-14.8（根据需要加浮动符号“～”）
对部分需要可调整尺寸精度的部件适用的中等偏低的公差等级
IT5(基孔制)（Z35钢标注在位置E/C），≤D4 ≥T3级管螺纹:（孔）、六角（薄型）; FJG垫圈、LH内六角圆柱头螺钉等材料也用此标准
螺纹中径公差等级大全对照表
公差等级
中径公差（μm）
适用范围
IT01
±4.8 - ±76.4
高精度、高稳定性，适用于精密机械部件和高端产品制造
IT00
±3.2 - ±57.9
次高等级，适用于一般精度要求的场合
IT9
+-1.6 - +-35.5
低精度要求，适用于普通连接件或非关键部位
IT8~IT7(从高到)
螺纹中径对照表
螺纹中径对照表公制螺纹美制NPSM螺纹（美国标准ANSI B1.20.1机械连接用直管螺纹60度）NPT布锥管螺纹标号螺纹代号基面上的直径螺纹长度端面大径大径中径小径管端至基面长有效长度02 Z1/8*27 10.242 9.489 8.736 4.102 6.703 9.986 04 Z1/4*18 13.616 12.487 11.385 5.786 10.206 13.254 06 Z3/8*18 17.055 15.926 14.797 6.096 10.358 16.674 08 Z1/2*14 21.223 19.772 18.321 8.128 13.556 20.715 12 Z3/4*14 26.568 25.117 23.666 8.611 13.861 26.030 16 Z1*11.5 33.228 31.461 29.694 10.160 17.343 32.593 20 Z1.1/4*1.5 41.985 40.218 38.451 10.668 17.953 41.318 24 Z1.1/2*11.5 48.054 46.287 44.520 10.668 18.377 47.38732 Z2*11.5 60.092 58.325 56.558 11.074 19.215 59.400 40 Z2.1/2*8 72.699 70.159 67.619 17.323 28.892 71.616 48 Z3*8 88.608 86.068 83.528 19.456 30.480 87.39255度英锥管螺纹55度英锥管螺纹美制螺纹可拆式芯子与套筒连接螺纹新西兰B09内螺纹标号你螺纹代号大径MIN中径MIN中径MAX小径MIN小径MAXB-09 0.860in*14 21.844 20.683 20.841 19.522NPTF+密封管螺纹备注：1.表中外螺纹的完整螺纹长度包括不超过一个螺距长度的倒角2.表中内螺纹的完整螺纹长度不包括在中径线和倒角交线外的锥口孔。
螺纹尺寸和公差
M米制粗牙螺纹基本牙型与尺寸和公差带H=^|-P=0,866025PHi=H=0.5r3l-'8H2=二0.61®川2dd2=D2=d-0.64952P di=d-2H=d-1t22687P「处—=0J4434代号（大径）d=D 螺距P螺纹中径d2=D2夕卜螺纹小径di内螺纹小径D1外螺纹全齿高H2配合齿高H1螺纹中径尺寸（6H公差带级别）丝锥螺纹中径（H2公差带级别为例）min max min maxM3 0.5 2.672 2.387 2.459 0.307 0.271 2.675 2.775 2.699 2.714 M3.5 0.6 3.110 2.764 2.850 0.368 0.325 3.110 3.222 3.137 3.155 M4 0.7 3.545 3.141 3.242 0.429 0.379 3.545 3.663 3.574 3.593 M5 0.8 4.480 4.019 4.134 0.491 0.433 4.480 4.605 4.510 5.530 M6 1.0 5.350 4.773 4.937 0.613 0.541 5.350 5.500 5.385 5.408 M7 1.0 6.350 5.773 5.937 0.613 0.541 6.350 6.500 6.385 6.408 M8 1.25 7.188 6.466 6.647 0.767 0.677 7.188 7.348 7.226 7.251 M10 1.5 9.026 8.160 8.376 0.920 0.812 9.026 9.206 9.068 9.096 M12 1.75 10.863 9.853 10.106 1.074 0.947 10.863 11.063 10.911 10.943 M14 2.0 12.701 11.546 11.835 1.227 1.083 12.701 12.913 12.752 12.786 M16 2.0 14.701 13.546 13.835 1.227 1.083 14.701 14.913 14.752 14.786 M18 2.5 16.373 14.933 15.294 1.534 1.353 16.376 16.600 16.430 16.466 M20 2.5 18.376 16.933 17.294 1.534 1.353 18.376 18.600 18.430 18.466 M22 2.5 20.376 18.933 19.294 1.534 1.353 20.376 20.600 20.430 20.466MF 米制细牙螺纹基本牙型与尺寸和公差带H=^-P=0,866025PH I =4-H=O.;：rjPcH ：=吕4：：：6刖、卅d2=D2=d-0.649b2Pdi=d-2H =d-k22687P r 匕—=0.-1-13^111b代号（大径） d=D 螺距 P 螺纹中径d2=D2 夕卜螺纹小径di内螺纹小径 D1 外螺纹全齿高H2 配合齿高H1 螺纹中径尺寸（6H 公差带级别）丝锥螺纹中径 （H2公差带级别为例）min max min max M3 0.35 2.773 2.571 2.621 0.215 0.189 2.773 2.863 2.794 2.809 M3.5 0.35 2.273 3.071 3.121 0.215 0.189 3.273 3.363 3.294 3.309 M4 0.5 3.675 3.387 3.459 0.307 0.271 3.675 3.775 3.699 3.714 M5 0.5 4.675 4.387 4.459 0.307 0.271 4.675 4.775 4.699 4.714 M6 0.75 5.513 5.080 5.188 0.460 0.406 5.513 5.645 5.545 5.566 M8 1.0 7.350 6.773 6.917 0.613 0.541 7.350 7.500 7.385 7.408 M10 1.0 9.350 8.773 8.917 0.613 0.541 9.350 9.500 9.385 9.408 M10 1.25 9.188 8.466 8.647 0.767 0.677 9.188 9.348 9.226 9.251 M12 1.25 11.188 10.466 10.647 0.767 0.677 11.188 11.368 11.226 11.251 M12 1.5 11.026 10.160 10.376 0.920 0.812 11.026 11.216 11.068 11.096 M14 1.5 13.026 12.160 12.376 0.920 0.812 13.026 13.216 13.068 13.096 M16 1.5 15.026 14.160 14.376 0.920 0.812 15.026 15.216 15.068 15.096 M18 1.5 17.026 16.160 16.376 0.920 0.812 17.026 17.216 17.068 17.096 M18 2.0 16.701 15.546 15.835 1.227 1.083 16.701 16.913 16.752 16.786 M20 1.5 19.026 18.160 18.376 0.920 0.812 19.026 19.216 19.068 19.096 M20 2.0 18.701 17.546 17.835 1.227 1.083 18.701 18.913 18.752 18.786 M221.521.02620.16020.3760.9200.81221.02621.21621.06821.096内螺纹外螺纹夕卜曝H=^p=0.866025P H I =工H 二N541即o H/=4H=0.61343^Z--1d2=D2=cl-C i .6/1952Pd 1=d-2H=d-1.22687P 「K tL =O ,14434P代号 （螺纹直径一 25.4m 内牙数）螺距P 螺纹大径d=D 螺纹中径d2=D2 内螺纹小径D1夕卜螺纹小径d1 螺纹中径尺寸 丝锥螺纹中径2B3Bm in 2B max 3B max min max N0.5—40 0.635 3.175 2.746 2.487 2.395 2.764 2.847 2.827 2.776 2.789 NO.6—32 0.794 3.505 2.990 2.647 2.532 2.990 3.084 3.058 3.105 3.028 NO.8—32 0.794 4.166 3.650 3.307 3.193 3.650 3.746 3.721 3.675 3.688 NO.10—24 1.058 4.826 4.138 3.680 3.528 4.138 4.247 4.219 4.963 4.176 NO.12—24 1.058 5.486 4.798 4.341 4.188 4.798 4.910 4.882 4.823 4.836 UNCl/4〃-20 1.270 6.350 5.524 4.976 4.793 5.524 5.646 5.616 5.575 5.588 UNC5/16〃-18 1.411 7.938 7.021 6.411 6.205 7.021 7.155 7.120 7.071 7.084 UNC3/8"-16 1.588 9.525 8.494 7.805 7.577 8.494 8.639 8.603 8.545 8.557 UNC7/16"-14 1.814 11.112 9.934 9.149 8.887 9.934 10.089 10.051 9.985 9.997 UNC1/2"-13 1.954 12.700 11.430 10.584 10.302 11.430 11.595 11.552 11.481 11.494 UNC9/16"-12 2.117 14.288 12.913 11.996 11.692 12.913 13.086 13.043 12.964 12.977 UNC5/8"-11 2.309 15.875 14.376 13.376 13.043 14.376 14.559 14.514 14.427 14.440 UNC3/4"-10 2.540 19.050 17.399 16.229 15.933 17.399 17.595 17.544 17.450 17.463 UNC7/8"-9 2.822 22.225 20.390 19.169 18.763 20.391 20.599 20.546 20.455 20.467 UNC1"-83.17525.40023.33821.96321.50423.33823.56123.50523.40123.414内f纹H=^|-P=0.866025PHi=等H二!1541芥□H2=TTY H=0.613-1,P d2=D2=d-0.6d952Pdi=d-2H=d-h2268r哉H=0.ri'13-1J6代号（螺纹直径一25.4m内牙数）螺距P螺纹大径d=D螺纹中径d2=D2内螺纹小径D1夕卜螺纹小径d1螺纹中径尺寸丝锥螺纹中径（2级）2B3Bmin2Bmax3Bmaxmin maxNO.5—44 0.577 3.175 2.799 2.550 2.466 2.799 2.880 2.860 2.812 2.824 NO.6—40 0.635 3.505 3.094 2.817 2.725 3.094 3.180 3.157 3.108 3.119 NO.8—36 0.706 4.166 3.708 3.401 3.299 3.708 3.800 3.777 3.721 3.734 NO.10—32 0.794 4.826 4.310 3.976 3.853 4.310 4.409 4.384 4.336 4.348 NO.12—28 0.907 5.486 4.897 4.503 4.374 4.897 5.004 4.976 4.923 4.935 UNCl/4〃-28 0.907 6.350 5.761 5.367 5.237 5.761 5.870 5.842 5.799 5.812 UNC5/16〃-24 1.058 7.938 7.249 6.792 6.640 7.249 7.371 7.341 7.287 7.300 UNC3/8"-24 1.058 9.525 8.837 8.379 8.227 8.837 8.961 8.931 8.875 8.887 UNC7/16"-20 1.270 11.112 10.287 9.738 9.555 10.287 10.424 10.391 10.338 10.351 UNC1/2"-20 1.270 12.700 11.874 11.326 11.143 11.874 12.017 11.981 11.925 11.938 UNC9/16"-18 1.411 14.288 13.371 12.761 12.555 13.371 13.520 13.482 13.421 13.434 UNC5/8"-18 1.411 15.875 14.958 14.348 14.143 14.958 15.110 15.072 15.009 15.022 UNC3/4"-16 1.588 19.050 18.019 17.330 17.102 18.019 18.184 18.143 18.070 18.082 UNC7/8"-14 1.814 22.225 21.046 20.262 20.000 21.046 21.224 21.181 21.110 21.123 UNC1"-12 2.117 25.400 24.026 23.109 22.804 24.026 24.219 24.171 24.089 24.102G(BSP)非螺纹密封的管螺纹基本牙型与尺寸内蝶纹25.4卩―每内牙数H=0.96049PH1=0+640327P10J37329PH/6=0.160082螺纹代号每25.4mm内牙数螺距Pmm螺纹大径d=Dmm螺纹中径d2=D2mm螺纹小径d1=D1mmH1mmR~mm螺纹中径公差带丝锥螺纹中径公差带min max min maxG1/8〃28 0.907 9.728 9.147 8.566 0.581 0.125 9.147 9.254 9.177 9.194 G1/4〃19 1.337 13.147 12.301 11.445 0.856 0.184 12.301 12.426 12.366 12.356 G3/8〃19 1.337 16.662 15.806 14.950 0.856 0.184 15.806 15.933 15.801 15.861 G1/2〃14 1.814 20.955 19.793 18.631 1.162 0.249 19.793 19.935 19.828 19.848 G5/8〃14 1.814 22.911 21.749 20.587 1.162 0.249 21.749 21.891 21.784 21.804 G3/4〃14 1.814 26.441 25.279 24.117 1.162 0.249 25.279 25.421 25.314 25.334 G7/8〃14 1.814 32.201 29.039 27.877 1.162 0.249 29.039 29.181 29.074 29.094 G1〃11 2.309 33.249 31.770 30.291 1.479 0.317 31.770 31.950 31.815 31.839 G1-1/8〃11 2.309 37.897 36.418 34.939 1.479 0.317 36.418 36.598 36.463 36.487 G1-1/4〃11 2.309 41.910 40.431 38.952 1.479 0.317 40.431 40.611 40.476 40.500 G1-3/8〃11 2.309 44.323 42.844 41.365 1.479 0.317 42.844 43.024 42.889 42.913 G1-1/2〃11 2.309 47.803 46.324 44.845 1.479 0.317 46.324 46.504 46.374 46.398 G1-3/4〃11 2.309 53.746 52.267 50.788 1.479 0.317 52.267 52.447 52.327 52.354 G2〃11 2.309 59.614 58.135 56.656 1.479 0.317 58.135 58.315 58.195 58.222丝锥图标与符号说明:螺纹类型:螺孔型式M——米制粗牙普通螺纹T1通孔一-W1.2dMF ——―米制细牙普通螺纹T2通孔一--W2dUNC —―统一粗牙螺纹B1不通孔-——W1.2dUNF —―统一细牙螺纹B2不通孔-——W1.8dG(BSP)—―非螺纹密封的管螺纹B3不通孔-——W2.2dW(BSW)-―惠氏螺纹NPT ———60°牙形角圆锥管螺纹d为螺纹大径RP ——用螺纹密封的圆柱管螺纹RC(BSPT)――用螺纹密封的圆柱管螺纹EC ——安装钢丝螺套用内螺纹螺纹齿形角:丝锥类别:60°55 N——加工普通结构钢、软的灰铸铁中等硬度的有色金属H――加工特别硬的、硬而韧的材料W――加工特别软与韧的材料丝锥结构种类：丝锥切削锥长度：直槽丝锥螺尖丝锥螺旋槽丝锥跳牙丝锥A型带冷却孔丝锥（用于不通孔）B型带冷却孔丝锥（用于通孔）挤压丝锥带油槽挤压丝锥钻攻复合丝锥X——（5〜6P）Y——（4~5P）Z——（2〜3P）丝锥柄部采用的标准GB4267DIN10-1丝锥螺纹公差带等级：丝锥采用的标准：中国国家标准中国机械行业标准JB国际标准ISO德国标准带级别的螺纹丝锥材料：HSS——普通高速钢HSS-E——高性能高速钢HSS-PM——粉末冶金高速钢Hm硬质合金丝锥刃倾角、螺旋角：螺尖丝锥的刃倾角入1——12°入2——18°螺旋槽丝锥的螺旋角B1——20°B2——30B3——40°H1——适合加工米制内螺纹4H5H公差带级别的螺纹H2——适合加工米制内螺纹5G6H公差带级别的螺纹H3——适合加工米制内螺纹6G7H7G带级别的螺纹1——适合加工统一螺纹内螺纹1B公差级别的螺纹2——适合加工统一螺纹内螺纹2B公差级别的螺纹W2――适合加工惠氏内螺纹中等级公差级别的螺纹W3――适合加工惠氏内螺纹普通级公差级别的螺纹。
常用螺纹尺寸与公差汇总表
0.-0.125
0，-0.250
0，-0.250
0，-0.250
06
G3/8*19
16.662
15.806
14.950
0.125，0
0.445，0
0，-0.125
0，-0.250
0，-0.250
0，-0.250
08
G1/2*14
20.955
19.793
18.631
0.142，0
0.541，0
M33*1.5
33
32.026
31.376
0,+0.200
0,+0.300
0,+0.250
0,+0.375
-0.032,-0.182
-0.032,-0.268
M36*1.5
36
35.026
34.376
0,+0.200
0,+0.300
0,+0.250
0,+0.375
-0.032,-0.182
-0.032,-0.268
M39*1.5
39
38.026
37.376
0,+0.200
0,+0.300
0,+0.250
0,+0.375
-0.032,-0.182
-0.032,-0.268
M42*1.5
42
41.026
40.376
0,+0.200
0,+0.300
0,+0.250
0,+0.375
-0.032,-0.182
-0.032,-0.268
新_旧普通螺纹国标公差对照表
6H 比 2 级大 25%~50%，5H
P≤0.8 时近似相 等
6H，由于 TD2 不得 大于 0.25P 所以
内
2级
时用 4H，P=0.25 用 5H
（都是零）
与 2 级近似相等 4H 比 2 级小 11% 5H 比 2 级大 12%
P>0.8 时 6H 比 2 级大 20~30%
P≤0.25 时大于 5H 的公差不列出， P<0.5 时 6H 的公差
新、旧普通螺纹国标公差对照表
GB197-63 新国标公差带 极限偏差对比 中径公差对比 精度等级
顶径公差对比
备注
P≤0.8 时 5H 比 1
1级
4H5H
下偏差重合 （都是零）
4H 比 1 级大 25~55%
级约小 20%， P>0.8 时相差±
10% 尽可能优先选用
6H 或 5H6H p=0.2 下偏差重合
7h6h
上偏差重合
近似相等，P 小 时稍小，P 大时 稍大，相差± 10%个别达到
20% 6h 比 3 级小 35% 7h 比 3 级小 20%
8h 比 3 级大 7~20%，6h 与 3
级差±13%
过渡期用 8h，一般 应优先选 6g6h，由
于 Td2 不得大于 Td，所以 P≤0.3 时， 大于 6h 的公差不列
时，4h 稍小 P 大时，4h 稍大， 相差 10%个别达
4h 比 1 级小 30~40%
螺
2级
20%
近似相等，P 小
上偏差重合 时，6h6g 稍小
6h
（都是零） P 大时，6g 稍大，
相差 10%个别达
近似相等
优先选用 6g
螺纹基本尺寸对照表
英制管螺纹基本尺寸及公差（牙形角55º） BSPP螺纹代号基本直径内螺纹外螺纹大径中径小径中径公差小径公差A级B级中径公差大径公差中径公差大径公差G1/8″×289.7289.1478.566+0.170+0.282-0.107-0.214-0.214-0.214G1/4″×1913.15712.30111.445+0.125+0.445-0.125-0.250-0.2500-0.250G3/8″×1916.66215.80614.950+0.125+0.445-0.125-0.250-0.250-0.250G1/2″×1420.95519.79318.631+0.142+0.541-0.142-0.284-0.284-0.284G5/8″×1422.91121.74920.587+0.142+0.541-0.142-0.284-0.284-0.284G3/4″×1426.44125.27924.117+0.142+0.541-0.142-0.284-0.284-0.284G1″×1133.24931.77030.291+0.180+0.640-0.180-0.360-0.360-0.360G1.1/4″×1141.91040.43138.952+0.180+0.640-0.180-0.360-0.360-0.360G1.1/2″×1147.80346.32444.854+0.180+0.640-0.180-0.360-0.360-0.360G2″×1159.61458.13556.656+0.180+0.640-0.180-0.360-0.360-0.360G2.1/2”X1175.18473.70572.226+0.217+0.640-0.217-0.434-0.434-0.434G3”X1187.88486.40584.926+0.217+0.640-0.217-0.434-0.434-0.434G3.1/2”X11100.33098.85197.372+0.217+0.640-0.217-0.434-0.434-0.434英制锥管螺纹基本尺寸及公差（牙形角55º） BSPT螺纹代号基面上的直径基准长度有效螺纹长度圆锥内螺纹基面轴向位移偏差（±mm）大径中径小径基本最大最小基本最大最小R1/8″×289.7289.1478.566 4.0 4.9 3.1 6.57.4 5.6 1.1 R1/4″×1913.15712.30111.445 6.07.3 4.79.711.08.4 1.7 R3/8″×1916.66215.80614.950 6.47.7 5.110.111.48.8 1.7 R1/2″×1420.95519.79318.6318.210.0 6.413.215.011.4 2.3 R3/4″×1426.44125.27924.1179.511.37.714.516.312.7 2.3 R1″×1133.24931.77030.29110.412.78.116.819.114.5 2.9 R1.1/4″×1141.91040.43138.95212.715.010.419.121.416.8 2.9 R1.1/2″×1147.80346.32444.84512.715.010.419.121.416.8 2.9 R2″×1159.61458.13556.65615.918.213.623.425.721.1 2.9 R2.1/2”X1175.18473.70572.22617.521.014.026.730.223.2 3.5 R3”X1187.88486.40584.92620.624.117.129.833.326.3 3.5 R3.1/2”X11100.33098.85197.37222.225.718.731.434.927.9 3.5美制管螺纹基本尺寸及公差（牙形角60º） UN(F)螺纹代号外螺纹内螺纹公差等级公差等级2A2B大径中径小径小径中径大径最大最小最大最小最小最大最小最大JIC螺纹7/16″×20UNF11.07910.87410.25410.1479.5689.72810.03310.28710.42411.113 1/2″×20UNF12.66712.46111.84111.73211.15611.32811.60811.87512.01712.7 9/16″×18UNF14.25214.03113.33513.22112.57312.75113.08113.37113.5214.288 3/4″×16UNF19.01218.77317.98117.85417.1217.32317.67818.01918.18419.05 7/8″×14UNF22.18421.92321.00620.86920.02520.26920.67621.04621.22422.225 1-1/16″×12UN26.94426.65525.5725.42524.42524.68925.14625.61325.80126.988 1-5/16″×12UN33.29433.00531.9231.77330.77531.03931.49631.96332.15433.338 1-5/8″×12UN41.22940.9439.88539.70538.7138.98939.44639.90140.09441.275 1-7/8″×12UN47.57947.2946.20546.05345.0645.33945.79646.25146.44947.625 2-1/2″×12UN63.45263.16262.07861.9260.93261.21461.67162.12662.33263.5ORFS螺纹9/16″×18UNF14.25214.03113.33513.22112.57312.75113.08113.37113.5214.288 11/16″×16UN17.42717.18816.39616.27415.53515.74816.10416.43116.58917.463 13/16″×16UN20.59920.36119.56819.44418.70718.92319.27919.60619.76620.638 1″×14UNF25.35725.09524.17824.03623.19523.44423.82524.22124.40725.4 1-3/16″×12UN30.11929.8328.74528.59827.627.86428.32128.78828.97930.163 1-7/16″×12UN36.46736.17735.09334.94333.94734.21434.67135.13835.33136.513 1-11/16″×12UN42.81742.52741.44341.2940.29740.56441.02141.48841.68642.863 2″×12UN50.75450.46549.3849.22548.23548.51448.97149.42649.62750.8SAE螺纹5/8″×18UNF15.83915.61814.92314.80314.16114.35114.68114.95815.1115.875 1-1/16″×14UN26.94726.68325.74325.60824.7424.96825.37525.78325.96126.987其它美制螺纹9/16″×16UN14.25214.01313.22113.10112.3612.57312.92913.25613.41114.288 7/8″×12UN22.18221.89220.80820.66819.66219.93920.39620.85121.03422.225 2-1/4″×12UN57.10456.81555.7355.57554.58554.86455.32155.77655.97657.15注：UNC粗牙螺纹系列，UNF细牙螺纹系列， UNEF超细牙螺纹系列， UN不变螺距系列布锥管螺纹基本尺寸及公差(牙形角60º) NPT螺纹代号基面上的直径螺纹长度大径中径小径有效长度管端至基面长Z1/8″×2710.2729.5198.7667 4.572 Z1/4″×1813.57212.44311.3149.5 5.080 Z3/8″×1817.05515.92614.79710.5 6.096 Z1/2″×1421.22319.77218.32113.58.028 Z3/4″×1426.56825.11723.666148.611 Z1″×11.533.22831.46129.69417.510.160 Z1.1/4″×11.541.98540.21838.4511810.688 Z1.1/2″×11.548.05446.28744.52018.510.688 Z2″×11.560.09258.32556.5581911.074公制螺纹基本尺寸及公差(牙形角60º) M螺纹代号基本直径内螺纹外螺纹大径中径小径公差等级公差等级6H7H6g中径公差小径公差中径公差小径公差中径公差大径公差M10X1109.3508.917+0.150+0.236+0.190+0.300-0.026-0.138-0.026-0.206M12X11211.35010.917+0.160+0.236+0.200+0.300-0.026-0.144-0.026-0.206M14X11413.35012.917+0.160+0.236+0.200+0.300-0.026-0.144-0.026-0.206M12X1.251211.18810.647+0.180+0.265+0.224+0.335-0.028-0.160-0.028-0.240M14X1.251413.18812.647+0.180+0.265+0.224+0.335-0.028-0.160-0.028-0.240M12X1.51211.02610.376+0.190+0.300+0.236+0.375-0.032-0.172-0.032-0.268M14X1.51413.02612.376+0.190+0.300+0.236+0.375-0.032-0.172-0.032-0.268M16X1.51615.02614.376+0.190+0.300+0.236+0.375-0.032-0.172-0.032-0.268M18X1.51817.02616.373+0.190+0.300+0.236+0.375-0.032-0.172-0.032-0.268M20X1.52019.02618.376+0.190+0.300+0.236+0.375-0.032-0.172-0.032-0.268M22X1.52221.02620.376+0.190+0.300+0.236+0.375-0.032-0.172-0.032-0.268M24X1.52423.02622.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M26X1.52625.02624.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M27X1.52726.02625.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M30X1.53029.02628.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M33X1.53332.02631.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M36X1.53635.02634.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M39X1.53938.02637.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M42X1.54241.02640.376+0.200+0.300+0.250+0.375-0.032-0.182-0.032-0.268M27X22725.70124.835+0.224+0.375+0.280+0.475-0.038-0.208-0.038-0.318M30X23028.70127.835+0.224+0.375+0.280+0.475-0.038-0.208-0.038-0.318M33X23331.70130.835+0.224+0.375+0.280+0.475-0.038-0.0380000-0.208-0.318M36X23634.70133.835+0.224+0.375+0.280+0.475-0.038-0.208-0.038-0.318M39X23937.70136.835+0.224+0.375+0.280+0.475-0.038-0.208-0.038-0.318M42X24240.70139.835+0.224+0.375+0.280+0.475-0.038-0.208-0.038-0.318M45X24543.70142.835+0.224+0.375+0.280+0.475-0.038-0.208-0.038-0.318M52X25250.70149.835+0.236+0.375+0.300+0.475-0.038-0.218-0.038-0.318M60X26058.70157.835+0.236+0.375+0.300+0.475-0.038-0.218-0.038-0.318M64X26462.70161.835+0.236+0.375+0.300+0.475-0.038-0.218-0.038-0.318M72X27270.70169.835+0.236+0.375+0.300+0.475-0.038-0.218-0.038-0.318。
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各种公差带的丝锥所能加工的内螺纹公差带对照表：
用于丝锥切出的螺纹精度不仅取决于丝锥本身的精度，而且还取决于其它许多因素，这些因素与刀具（切削锥径向跳动，中径尺寸，前角，磨纯度等）以及使用情况（工件材料，切削用量，切削液，机床精度，夹紧方式，丝锥辅具的结构，操作者的熟练程度等)有关，因此并不完全根据被加工内螺纹的公差等级来确定丝锥螺纹的精度等级。
成量工具
用于丝锥切出的螺纹精度不仅取决于丝锥本身的精度，而且还取决于其它许多因素，这些因素与刀具（切削锥径向跳动，中径尺寸，前角，磨纯度等）以及使用情况（工件材料，切削用量，切削液，机床精度，夹紧方式，丝锥辅具的结构，操作者的熟练程度等)有关，因此并不完全根据被加工内螺纹的公差等级来确定丝锥螺纹的精度等级。
由于影响螺纹精度的因素很多，表中所列仅供选择丝锥时做参考。
应按加工条件根据生产经验或通过试验，在标准所列范围内选用最适当的公差带的丝锥。
美制螺纹：
美制螺纹，又名统一螺纹。
1864年，美国人威利.赛特斯（Willian Sellers）参照英国惠氏螺纹标准体系制定了美国国家螺纹（N）。
这两种螺纹在直径与螺距系列和公差方面很相近。
起源：
美国国家螺纹的牙型（牙型角为60，削平高度为H/8）不同于
惠氏螺纹牙型（牙型角为55，削平高度为H/6）。
在美国工业影响的地区和行业，美国国家螺纹得到广泛应用。
第二次世界大战中，由于盟军所使用的螺纹标准不统一，后勤补给困难给盟军造成了严重的经济损失和人员伤亡。
二战刚结束，美国英国和加拿大等盟国马上着手制定盟国间统一的螺纹标准，于1948年颁布了统一螺纹标准。
由于当时美国的经济实力和军事实力在盟军内占主导地位，因此统一螺纹主要是依据美国国家螺纹标准而制定的，统一螺纹代号“UN”的前一个字母“U”来源于盟国间的“统一”；后一个字母“N”来源于美国国家螺纹的代号“N”。
从此，统一螺纹开始挤占英国惠氏螺纹原有的使用市场。