美制螺纹标准对照表
美制螺纹尺寸对照表
最小最大最小最大 8-320.15710.16310.13990.14280.1248(0.164-32) 3.9903 4.1427 3.5535 3.6271 3.1699 10-240.18180.1890.15860.16190.1379(0.190-24) 4.6177 4.8006 4.0284 4.1123 3.5027 12-240.20780.2150.18450.18790.1639(0.216-24) 5.2781 5.461 4.6863 4.7727 4.1631 1/4-200.24080.24890.21270.21640.1876(0.250-20) 6.1163 6.3221 5.4026 5.4966 4.765 5/16-180.30260.31130.27120.27520.2431(0.3175-18)7.6867.907 6.8885 6.9901 6.1747 3/8-160.36430.37370.32870.33310.297(0.375-16)9.25329.4928.3498.46077.5438 7/16-140.42580.43610.3850.38970.3485(0.4375-14)10.815311.07699.7799.89848.8519 1/2-130.48760.49850.44350.44850.4041(0.50-13)12.38512.661911.264911.391910.26419/16-120.54950.56090.50160.50680.4587(0.5625-12)13.957314.246912.740612.872711.651 5/8-110.61130.62340.55890.56440.5119(0.625-11)15.52715.834414.196114.335813.0023 3/4-100.73530.74820.67730.68320.6255(0.750-10)18.676619.004317.203417.353315.8877 7/8-90.85920.87310.79460.80090.7368(0.875-9)21.823722.176720.182820.342918.71471"-80.9830.9980.910.91680.8446(1.000-8)24.968225.349223.11423.286721.4528最小最大最小最大 8-360.15770.16320.14240.14520.1291(0.164-36) 4.0056 4.1453 3.617 3.6881 3.2791 10-320.18310.18910.16580.16880.1508(0.190-32) 4.6507 4.8031 4.2113 4.2875 3.8303 12-280.20850.2150.18860.19180.1712美制外螺纹（2A）常用规格极限尺寸表（粗牙）公称尺寸和每英寸牙数螺纹系列代号大径极限中径极限小径max 1.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。
美制螺纹标准对照表
美制螺纹标准对照表美制外螺纹（2A）常用规格极限尺寸表（粗牙）公称尺寸和每英寸牙数螺纹系列代号大径极限中径极限小径max螺胚直径最小最大最小最大最小最大8-32UNC 0.1571 0.1631 0.1399 0.1428 0.12483.58 3.61(0.164-32) 3.9903 4.1427 3.5535 3.6271 3.169910-24 0.1818 0.1890 0.1586 0.1619 0.13794.07 4.10(0.190-24) 4.6177 4.8006 4.0284 4.1123 3.502712-24 0.2078 0.2150 0.1845 0.1879 0.16394.72 4.75(0.216-24) 5.2781 5.4610 4.6863 4.7727 4.16311/4-20 0.2408 0.2489 0.2127 0.2164 0.18765.45 5.48(0.250-20) 6.1163 6.3221 5.4026 5.4966 4.76505/16-18 0.3026 0.3113 0.2712 0.2752 0.24316.94 6.98(0.3175-18) 7.6860 7.9070 6.8885 6.9901 6.17473/8-16 0.3643 0.3737 0.3287 0.3331 0.29708.40 8.44(0.375-16) 9.2532 9.4920 8.3490 8.4607 7.54387/16-14 0.4258 0.4361 0.3850 0.3897 0.34859.83 9.87(0.4375-14) 10.8153 11.0769 9.7790 9.8984 8.85191/2-13 0.4876 0.4985 0.4435 0.4485 0.404111.34 11.38(0.50-13) 12.3850 12.6619 11.2649 11.3919 10.26419/16-12 0.5495 0.5609 0.5016 0.5068 0.458712.80 12.84(0.5625-12) 13.9573 14.2469 12.7406 12.8727 11.65105/8-11 0.6113 0.6234 0.5589 0.5644 0.511914.27 14.32(0.625-11) 15.5270 15.8344 14.1961 14.3358 13.00233/4-10 0.7353 0.7482 0.6773 0.6832 0.625517.28 17.33(0.750-10) 18.6766 19.0043 17.2034 17.3533 15.88777/8-9 0.8592 0.8731 0.7946 0.8009 0.736820.27 20.32(0.875-9) 21.8237 22.1767 20.1828 20.3429 18.71471"-8 0.9830 0.9980 0.9100 0.9168 0.844623.22 23.27(1.000-8) 24.9682 25.3492 23.1140 23.2867 21.45281.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。
美制统一螺纹表UNC,UNF
第 2 页，共 45 页
美制标准系列统一螺
公称 基本大经 牙数 系列 直径 D，d(in) n 代号 9/16 0.5625 9/16 0.5625 5/8 5/8 5/8 5/8 5/8 5/8 5/8 5/8 0.6250 0.6250 0.6250 0.6250 0.6250 0.6250 0.6250 0.6250 28 32 11 12 16 18 20 24 28 32 12 16 20 24 28 32 10 12 16 20 28 32 12 16 UN UN UNC UN UN UNF UN UNEF UN UN UN UN UN UNEF UN UN UNC UN UNF UNEF UN UN UN UN 基本中经 D2，d2 0.5393 0.5422 0.5660 0.5709 0.5844 0.5889 0.5925 0.5979 0.6018 0.6047 0.6334 0.6469 0.6550 0.6604 0.6643 0.6672 0.6850 0.6959 0.7094 0.7175 0.7268 0.7297 0.7584 0.7719 UNR外螺纹设 内螺纹基本小 计牙型小径 径D1 d3(参考) 0.5238 0.5287 0.5266 0.5348 0.5573 0.5649 0.5709 0.5799 0.5863 0.5912 0.5973 0.6198 0.6334 0.6424 0.6488 0.6537 0.6417 0.6598 0.6823 0.6959 0.7113 0.7162 0.7223 0.7448 0.5187 0.5242 0.5135 0.5228 0.5483 0.5568 0.5637 0.5739 0.5812 0.5867 0.5853 0.6108 0.6262 0.6364 0.6437 0.6492 0.6273 0.6478 0.6733 0.6887 0.7062 0.7117 0.7103 0.7358 公制对照表(mm) 基本大经 D，d 14.2875 14.2875 15.8750 15.8750 15.8750 15.8750 15.8750 15.8750 15.8750 15.8750 17.4625 17.4625 17.4625 17.4625 17.4625 17.4625 19.0500 19.0500 19.0500 19.0500 19.0500 19.0500 20.6375 20.6375 (内)小径D1 13.3055 13.4282 13.3753 13.5836 14.1565 14.3474 14.5002 14.7293 14.8930 15.0157 15.1711 15.7440 16.0877 16.3168 16.4805 16.6032 16.3004 16.7586 17.3315 17.6752 18.0680 18.1907 18.3461 18.9190 (外)小径d3 13.3055 13.4282 13.3753 13.5836 14.1565 14.3474 14.5002 14.7293 14.8930 15.0157 15.1711 15.7440 16.0877 16.3168 16.4805 16.6032 16.3004 16.7586 17.3315 17.6752 18.0680 18.1907 18.3461 18.9190 螺距P 0.9071 0.7938 2.3091 2.1167 1.5875 1.4111 1.2700 1.0583 0.9071 0.7938 2.1167 1.5875 1.2700 1.0583 0.9071 0.7938 2.5400 2.1167 1.5875 1.2700 0.9071 0.7938 2.1167 1.5875 中经公差 容隙 2A 0.003715 0.003521 0.005501 0.005443 0.004769 0.004652 0.004324 0.004004 0.003759 0.003565 0.005485 0.004811 0.004366 0.004046 0.003801 0.003607 0.005894 0.005524 0.005024 0.004405 0.003840 0.003646 0.005561 0.004887 es 1A和2A 0.001115 0.001056 0.001650 0.001633 0.001431 0.001396 0.001297 0.001201 0.001128 0.001070 0.001646 0.001443 0.001310 0.001214 0.001140 0.001082 0.001768 0.001657 0.001507 0.001322 0.001152 0.001094 0.001668 0.001466
美制螺纹标准对照表(精品)
美制螺纹标准对照表美制外螺纹(２A)常用规格极限尺寸表(粗牙）公称尺寸和每英寸牙数螺纹系列代号大径极限中径极限小径maｘ螺胚直径最小最大最小最大最小最大8－32UNC ０.１571０.1６310.13990.14２80.１２48３.５８３.61(0.16４－32)3.９9０3４.1４27３.5５３53．62７13.16９910-240.1818０.18９00.15860.16１9０.１3794.07４.1０(0.190-24)4.6１774．80064.02844.1123３.５02７12-2４０．２0780.21500.1８４50.18790.1639４.724．7５(0.216－24)5.27８15．46104.６8６34.７727４．16３1１／4-20０.２４0．２4890.21270.21６４0.1876５．45５.4808(０.250 -20)6.11６3６.3２２1５.40265．４9６6４.76５05/１6-180.3０260.3113０．2７１20.27520.243１6.946.98(０．31 75-18)７.68607.90７６.８８856.99016．１7４73/8-1 60.36430．3７３70.32870.3３3１０．２９70８．408.44(0.375-16)9.25329.49２０8.34908.46０77.54３87／16-140.42580.４３61０.３8５0０.3897０.３48５9.839.87(０．437５-14)10．8１5311．076９９.779９.８9848.８5191/2－１30.４8760．4９８50.44350.44８50.404111．3411.３8(0．50-13)12.3850１2.661９11.26４９11．3９1９10.2641９/16－０．０.560０．５0．５００.451１１2５49５9０1６６8８7２．８02．84(０．5６25-1２)１3.957３１４．２46912.740612.8７2711．６5105／８-1１0．６1１3０.623４０.55890.56４40．５11914.27１4．3２(0．625 -11)15.527０1５.83４414.196114．3３581３.00233／4-100.73530.74820.6７7３0.６832０.6２5５17.28１７.33(0.７5０-10）18.676619.004317.2０3417.35３315.8８77７/８-9０．859２０.87310.79460.800９0.７36820．27２0.32(0.８７5-9)21．82372２.17６720．1８2８20．3429１8.714７１"-8０.９０.9９800．９１0０0.91680．84４623.222３．83027(1.０00-8）２4.968225.３49223.114０23．２86721.4５281.螺胚直径指滚丝前的尺寸,数值为依经验公式计算而得，在实践中需验证。
美制螺纹标准对照表
美制螺纹标准对照表美制外螺纹（2A）常用规格极限尺寸表（粗牙）公称尺寸和每英寸牙数螺纹系列代号大径极限中径极限小径max螺胚直径最小最大最小最大最小最大8-32UNC 0.15710.16310.13990.14280.12483.58 3.61(0.164-32) 3.9903 4.1427 3.5535 3.6271 3.169910-240.18180.18900.15860.16190.13794.07 4.10 (0.190-24) 4.6177 4.8006 4.0284 4.1123 3.502712-240.20780.21500.18450.18790.16394.72 4.75 (0.216-24)5.2781 5.4610 4.6863 4.7727 4.16311/4-200.24080.24890.21270.21640.18765.45 5.48 (0.250-20)6.1163 6.3221 5.4026 5.4966 4.76505/16-180.30260.31130.27120.27520.24316.94 6.98 (0.3175-18)7.68607.9070 6.8885 6.9901 6.17473/8-160.36430.37370.32870.33310.29708.408.44 (0.375-16)9.25329.49208.34908.46077.54387/16-140.42580.43610.38500.38970.34859.839.87 (0.4375-14)10.815311.07699.77909.89848.85191/2-130.48760.49850.44350.44850.404111.3411.38 (0.50-13)12.385012.661911.264911.391910.26419/16-120.54950.56090.50160.50680.458712.8012.84 (0.5625-12)13.957314.246912.740612.872711.65105/8-110.61130.62340.55890.56440.511914.2714.32 (0.625-11)15.527015.834414.196114.335813.00233/4-100.73530.74820.67730.68320.625517.2817.33 (0.750-10)18.676619.004317.203417.353315.88777/8-90.85920.87310.79460.80090.736820.2720.32 (0.875-9)21.823722.176720.182820.342918.71471"-80.98300.99800.91000.91680.844623.2223.27 (1.000-8)24.968225.349223.114023.286721.45281.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。
美制螺纹标准
美制螺纹美制标准螺纹（也称统一制螺纹）量规用于检测螺纹的内外牙，螺纹牙形角60度，由外径、每英寸牙数、精度组合表示，如1/4-20UNC-2B，表示1/4英寸外径、每英寸20牙、2B精度内螺纹塞规，若是左旋旋向，应加LH表示。
美制内螺纹默认精度为2B，3B紧密级亦可提供，此外美制外螺纹的默认精度为2A，紧密级精度为3A，订货时注明精度，不提供精度按默认精度提供。
美制螺纹系列众多，美制粗牙（UNC）、美制细牙（UNF）、美制特细牙（UNEF）、美制不变螺距螺纹（UN）、美制特殊螺纹（UNS）。
还有一些美制牙将另外描叙。
第二次世界大战中，盟军的武器和装备所使用的螺纹主要有两种：一种是英国的惠氏螺纹（BSW、BSF）；另一种是美国国家螺纹（UNC、UNF、UNEF、UN、UNS）；由于两种螺纹的标准不统一，给盟军造成了严重的经济损失和人员伤亡。
二战结束以后，美国、英国和加拿大等盟国马上制定了统一的螺纹标准，由于当时美国的经济实力和军事实力在盟军中占主导地位，统一制螺纹主要是依据美国国家螺纹标准制定的，因此，在紧固螺纹领域，统一制螺纹开始挤占英国惠氏螺纹的使用市场，惠氏螺纹的圆弧牙顶和牙底牙型，叫英国吃了苦果；另外，澳大利亚、马来西亚、印度尼西亚、阿根廷、智利、比利时、匈牙利、意大利、瑞典、捷克等各国家也制定了惠氏螺纹国家标准。
现在世界各国使用惠氏螺纹（BSW、BSF）的国家在不断减少，取而代之的是统一制螺纹（UNC、UNF、UNEF、UN、UNS）。
美制螺纹（UNC、UNF、UNEF、UN、UNS）相关规格：NO：0-80UNF、NO：1-64UNC、NO：2-56UNC、NO：3-48UNC、NO：4-40UNC、NO：4-48UNF、NO：5-40UNC、NO：6-32UNC、NO：6-40UNF、NO：8-32UNC、NO：8-36UNC、NO：10-24UNC、NO：10-32UNF、NO：10-40UNS、NO：12-24UNC、NO：12-28UNF、NO：12-36UNS、1/4-20UNC、1/4-24UNS、1/4-28UNF、1/4-32UNEF、5/16-18UNC、5/16-20UN、5/16-24UNF、5/16-27UNS、5/16-32UNEF、3/8-16UNC、3/8-20UN、3/8-24UNF、3/8-32UNEF、7/16-14UNC、7/16-20UNF、7/16-24UNS、7/16-28UNEF、1/2-12UNS、1/2-13UNC、1/2-16UN、1/2-20UNF、1/2-28UNEF、9/16-12UNC、9/16-18UNF、9/16-24UNEF、5/8-11UNC、5/8-18UNF、5/8-24UNEF、3/4-10UNC、3/4-16UNF、3/4-20UNEF、3/4-24UNS、7/8-14UNF、7/8-20UNEF、7/8-24UNS、15/16-28UN、1"-8UNC、1"-12UNF、1"-20UNEF、1-1/8-12UNF、1-1/8-16UN、1-1/4-7UNC、1-1/4-12UNF、1-1/2-6UNC等等。
美制螺纹对照表.xls
螺纹小径螺纹外径MaxMin Max Min Max Min Max Min Max Min 1-64UNC640.2360.3972A 1.83896 1.74244 1.58242 1.53162 1.366522B 1.42494 1.58242 1.59766 1.6637 1.8542 1.3973A1.8542 1.75768 1.59766 1.55956 1.381763B 1.42494 1.58242 1.59766 1.64592 1.8542 1.3971-72UNF720.210.3532A 1.83896 1.75006 1.61036 1.5621 1.419862B 1.4732 1.6129 1.6256 1.6891 1.8542 1.51133A1.8542 1.7653 1.6256 1.59004 1.43513B 1.4732 1.6129 1.6256 1.67386 1.8542 1.51132-56UNC560.2710.4542A 2.16916 2.06502 1.87452 1.82118 1.630682B 1.69418 1.87198 1.88976 1.96088 2.1844 1.70183A2.1844 2.08026 1.88976 1.84912 1.645923B 1.69418 1.87198 1.88976 1.9431 2.1844 1.70182-64UNF640.2360.3972A 2.16916 2.07264 1.91262 1.86182 1.696722B 1.75514 1.91262 1.92786 1.99644 2.1844 1.7783A2.1844 2.08788 1.92786 1.88976 1.711963B 1.75514 1.91262 1.92786 1.97866 2.1844 1.7783-48UNC480.3150.5292A 2.49682 2.38252 2.15392 2.0955 1.864362B 1.94056 2.1463 2.1717 2.2479 2.5146 1.99393A2.5146 2.4003 2.1717 2.12852 1.882143B 1.94056 2.1463 2.1717 2.22758 2.5146 1.99393-56UNF560.2710.4542A 2.49682 2.39268 2.20218 2.1463 1.958342B 2.02438 2.1971 2.21996 2.29108 2.5146 2.05743A2.5146 2.41046 2.21996 2.17932 1.976123B 2.02438 2.1971 2.21996 2.2733 2.5146 2.05744-40UNC400.3780.6352A 2.82448 2.69494 2.413 2.3495 2.067562B 2.15646 2.38506 2.43332 2.51714 2.8448 2.18443A2.8448 2.71526 2.43332 2.38506 2.087883B 2.15646 2.38506 2.43332 2.49428 2.8448 2.18444-48UNF480.3150.5292A 2.82702 2.71272 2.48412 2.42316 2.194562B 2.27076 2.45872 2.5019 2.58064 2.8448 2.26063A2.8448 2.7305 2.5019 2.45618 2.212343B 2.27076 2.45872 2.5019 2.56032 2.8448 2.26065-40UNC400.3780.6352A 3.15468 3.02514 2.7432 2.67716 2.397762B 2.48666 2.69748 2.76352 2.84734 3.175 2.52733A3.175 3.04546 2.76352 2.71526 2.418083B 2.48666 2.69748 2.76352 2.82702 3.175 2.52735-44UNF440.3440.5772A 3.15722 3.0353 2.7813 2.7178 2.468882B 2.55016 2.74066 2.79908 2.88036 3.175 2.57813A3.175 3.05308 2.79908 2.75082 2.486663B 2.55016 2.74066 2.54508 2.86004 3.175 2.57816-32UNC320.4720.7942A 3.48488 3.33248 2.96926 2.89814 2.542B 2.6416 2.8956 2.98958 3.08356 3.5052 2.70513A3.5052 3.3528 2.98958 2.93624 2.560323B 2.6416 2.8956 2.98958 3.05816 3.5052 2.70516-40UNF400.3780.6352A 3.48488 3.35534 3.0734 3.00736 2.727962B 2.8194 3.0226 3.09372 3.18008 3.5052 2.87023A3.50523.375663.093723.042922.748283B2.81943.012443.093723.157223.50522.8702公称直径螺纹规格牙数牙高螺距公差代号螺纹外径钻孔直径0.073（#1）1.8540.086(#2)2.1840.099(3#)2.515螺纹中经公差代号螺纹小径螺纹中径0.112(#4)2.8450.125(#5)3.1750.138(#6）3.505螺纹小径螺纹外径MaxMin Max Min Max Min Max Min Max Min 公称直径螺纹规格牙数牙高螺距公差代号螺纹外径钻孔直径螺纹中经公差代号螺纹小径螺纹中径8-32UNC320.4720.7842A 4.14274 3.99034 3.62712 3.55346 3.197862B 3.302 3.5306 3.64998 3.7465 4.1656 3.45443A4.1656 4.0132 3.64998 3.5941 3.220723B 3.302 3.52806 3.64998 3.7211 4.1656 3.45448-36UNF360.4210.7062A 4.14528 4.00558 3.68808 3.61696 3.304542B 3.4036 3.6068 3.7084 3.79984 4.1656 3.45443A4.1656 4.0259 3.7084 3.65506 3.324863B 3.4036 3.59664 3.7084 3.77698 4.1656 3.454410-24UNC240.631.0582A 4.8006 4.61772 4.11226 4.02844 3.540762B 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11.988812.44612.9133614.00860814.287512.303763A14.287513.9979412.9133612.814311.767823B 11.988812.3012212.9133613.0454414.287512.303769/16-14UNS 14 1.081 1.8142A 14.249413.9877813.0708412.9438412.09042B 12.31912.725413.1089413.2740414.287512.303769/16-16UN160.861.5882A 14.2519414.0131813.220713.1013212.359642B 12.57312.928613.2562613.411214.287512.73A14.287514.0487413.2562613.1673612.39523B 12.57312.801613.2562613.373114.287512.79/16-18UNF180.8411.4111A 14.2519413.919213.33513.1622812.5731B 12.750813.08113.3705613.5966214.287513.096242A14.25981414.0309613.33513.220712.5732B 12.750813.08113.3705613.5204214.287513.096243A14.287514.0665213.3705613.284212.608563B 12.750812.9692413.3705613.4823214.287513.096249/16-20UN200.7561.272A 14.2544814.0487413.4289813.322312.743182B 12.903213.20813.46213.601714.287513.096243A14.287514.0817613.46213.3807212.77623B 12.903213.1114813.46213.5661414.287513.096249/16-24UNEF240.631.0582A 14.2570214.0741413.5686813.4696212.997182B 13.131813.385813.5991613.728714.287513.096243A14.287514.1046213.5991613.525513.027663B 13.131813.3197613.5991613.6956814.287513.096249/16-27UNS 270.560.9412A 14.2595614.0893813.6474213.5534413.139422B 13.258813.487413.6753613.7972814.287513.492489/16-28UN280.540.9072A14.2595614.0944613.6702813.576313.177522B13.309613.512813.6982213.8201414.287513.4924812.70.5625"14.288螺纹小径螺纹外径MaxMin Max Min Max Min MaxMinMaxMin 公称直径螺纹规格牙数牙高螺距公差代号螺纹外径钻孔直径螺纹中经公差代号螺纹小径螺纹中径3A14.287514.122413.6982213.627113.205463B 13.309613.4645413.6982213.7896614.287513.492489/16-32UN320.4720.7842A 14.262114.109713.7464813.6575813.317222B 13.436613.614413.7718813.8861814.287513.492483A14.287514.135113.7718813.7058413.342623B 13.436613.5737613.7718813.8582414.287513.492485/8-11UNC111.3752.3091A 15.8343615.3720814.3357614.1249413.086081B 13.385813.868414.376414.6481815.87513.492482A 15.8343615.5270214.3357614.1960613.086082B 13.385813.868414.376414.5592815.87513.492483A15.87515.5676614.376414.2722613.126723B 13.385813.6931414.376414.5135615.87513.492485/8-12UN121.262.1172A 15.8343615.544814.4602214.3230613.314682B 13.58914.046214.5008614.681215.87513.891263A15.87515.5854414.5008614.3967213.355323B 13.58913.8760214.5008614.6354815.87513.891265/8-14UNS 14 1.081 1.8142A 15.836915.5752814.6583414.528813.67792B 13.919214.325614.6964414.86458815.87513.891265/8-16UN160.861.5882A 15.8394415.6006814.808214.6862813.947142B 14.147814.503414.8437615.0012415.87514.28753A15.87515.6362414.8437614.7523213.98273B 14.147814.3814814.8437614.960615.87514.28755/8-18UNF180.8411.4111A 15.8394415.506714.922514.744714.16051B 14.35114.681214.9580615.189215.87514.683742A 15.8394415.6184614.922514.8031214.16052B 14.35114.681214.9580615.1104615.87514.683743A 15.87515.6032214.9580614.8691614.196063B 14.35114.554214.9580615.0723615.87514.683745/8-16UN200.7561.272A 15.8419815.6362415.0164814.9072614.330682B 14.503414.782815.049515.1917415.87514.683743A15.87515.6692615.049514.9682214.36373B 14.503414.6989815.049515.1561815.87514.683745/8-24UNEF240.631.0582A 15.8445215.6616415.1561815.0545814.584682B 14.73214.98615.1866615.3187415.87514.683743A15.87515.6921215.1866615.1104614.615163B 14.73214.9072615.1866615.2857215.87514.683745/8-27UNS 270.560.9412A 15.8470615.6768815.2349215.138414.726922B 14.85915.087615.2628615.3898615.87515.079985/8-28UN280.540.9072A 15.8470615.6819615.2577815.1612614.765022B 14.884415.11315.2857215.4101815.87515.079983A15.87515.709915.2857215.214614.792963B 14.884415.0520415.2857215.379715.87515.079985/8-32UN320.4720.7842A 15.8470615.6946615.3314415.2414.902182B 15.011415.214615.3593815.4762215.87515.079983A15.87515.722615.3593815.290814.930123B 15.011415.1612615.3593815.4482815.87515.0799811/16-12UN121.262.1172A17.4218617.132316.0477215.9105614.902182B15.163815.62116.0883616.268717.462515.476220.625"15.875螺纹小径螺纹外径MaxMinMaxMinMaxMin Max MinMaxMin 公称直径螺纹规格牙数牙高螺距公差代号螺纹外径钻孔直径螺纹中经公差代号螺纹小径螺纹中径3A17.462517.1729416.0883615.9842214.942823B 15.163815.455916.0883616.2229817.462515.4762211/16-16UN160.861.5882A 17.4269417.1881816.395716.2737815.534642B 15.74816.103616.4312616.5887417.462515.8753A17.462517.2237416.4312616.3398215.57023B 15.74815.9613616.4312616.548117.4625 1.587511/16-20UN200.7561.272A 17.4294817.2237416.6039816.4947615.918182B 16.078216.38316.63716.7792417.462516.271243A17.462517.2567616.63716.5557215.95123B 16.078216.2864816.63716.7436817.462516.2712411/16-24UNEF240.631.0582A 17.4320217.2491416.7436816.6420816.172182B 16.306816.560816.4947616.9062417.462516.271243A9.842517.2796216.7741616.6979616.30683B 16.306816.4947616.7741616.8732217.462516.2712411/16-28UN280.540.9072A 17.4345617.2694616.8452816.7487616.48462B 16.484616.687816.8732216.9976817.462516.667483A17.462517.297416.8732216.802116.48463B 16.484616.6395416.8732216.967217.462516.6674811/16-32UN320.4720.7942A 17.4345617.2821616.9189416.827516.489682B 16.611616.789416.9468817.0637217.462516.667483A17.462517.310116.9468816.878316.517623B 16.611616.7487616.9468817.0357817.462516.667483/4-10UNC101.5132.541A 19.0042818.5115217.3532817.1297615.979141B 16.306816.840217.39917.691119.0516.667482A 19.0042818.6766217.3532817.2034215.979142B 16.306816.840217.39917.5945819.0516.667483A19.0518.7223417.39917.2872416.024863B 16.306816.624317.39917.5437819.0516.667483/4-12UN121.262.1172A 19.0068218.7172617.6326817.4929816.487142B 16.76417.221217.6758617.8587419.0517.066263A19.0518.7604417.6758617.5717216.530323B 16.76417.0357817.6758617.8130219.0517.066263/4-14UNS 14 1.081 1.8142A 19.011918.7502817.8333417.703816.59892B 17.094217.475217.8714418.0416219.0517.066263/4-16UNF160.861.5881A 19.011918.6512217.9806617.7901617.11961B 17.322817.678418.0187618.2676819.0517.46252A19.011918.7731417.9806617.8536617.11962B 17.322817.678418.0187618.1838619.0517.46253A19.0518.8112418.0187617.9222417.15773B 17.322817.5463218.0187618.1432219.0517.46253/4-18UNS 180.841 1.4112A 19.0144418.7934618.326117.9806617.33552B 17.52617.856218.1330618.2854619.0517.46253/4-20UNEF200.7561.272A 19.0169818.8112418.1914818.0797217.505682B 17.678417.957818.224518.3692819.0517.858743A19.0518.8442618.224518.1406817.53873B 17.678417.8739818.224518.3337219.0517.858743/4-24UNEF240.631.0582A19.0195218.8366418.3311818.2270417.759682B17.90718.16118.3616618.4962819.0517.858740.6875"17.4630.75"19.05螺纹小径螺纹外径MaxMinMaxMinMaxMin Max Min Max Min 公称直径螺纹规格牙数牙高螺距公差代号螺纹外径钻孔直径螺纹中经公差代号螺纹小径螺纹中径3A19.0195218.8493418.4073818.3083217.899383B 18.03418.262618.4378618.567419.0517.858743/4-28UN280.540.9072A 19.0195218.8544218.4302418.3337217.937482B 18.059418.28818.4607218.5877219.0518.254983A19.0518.884918.4607218.3870617.967963B 18.059418.2270418.4607218.554719.0518.254983/4-32UN320.4720.7842A 19.0220618.8696618.5064418.41518.077182B 18.186418.389618.5343818.6537619.0518.254983A19.0518.897618.5343818.465818.105123B 18.186418.3362618.5343818.6258219.0518.2549813/16-10UNC101.5132.542A 20.5917820.2641218.986518.8366417.612362B 17.894318.427718.986519.278620.637518.254983A20.637520.3098419.0322218.9204617.520923B 17.894318.427718.986519.1820820.637518.2549813/16-12UN121.262.1172A 20.5943220.3047619.2201819.0804818.201642B 18.338818.79619.2633619.4462420.637518.653763A20.637520.3479419.2633619.1592218.117823B 18.338818.6156619.2633619.4005220.637518.6537613/16-16UN160.861.5882A 20.599420.3606419.5681619.443718.70712B 18.92319.278619.6062619.7662820.637519.053A20.637520.3987419.6062619.5148218.74523B 18.92319.1338219.6062619.7256420.637519.0513/16-20UNEF200.7561.272A 20.6044820.3987419.7789819.6672219.093182B 19.253219.55819.81219.9567820.637519.446243A20.637520.4317619.81219.7281819.12623B 19.253219.4614819.81219.9212220.637519.4462413/16-28UN280.540.9072A 20.6070220.4419220.0177419.9212219.524982B 19.659619.862820.0482220.1752220.637519.842483A20.637520.421620.0482219.9745619.555463B 19.659619.8145420.0482220.142220.637519.8424813/16-32UN320.4720.7842A 20.6095620.4571620.0939420.002519.664682B 19.786619.964420.1218820.2412620.637519.842483A20.637520.485120.1218820.053319.692623B 19.786619.9237620.1218820.2133220.637519.842487/8-9UNC91.682.8221A 22.1767421.6484220.3428620.1015618.816321B 19.17719.761220.8483220.7035422.22519.446242A 22.1767421.8236820.3428620.1828418.816322B 19.17719.761220.8483220.599422.22519.446243A22.22521.8719420.3911220.2717418.864583B 19.17719.5097420.8483220.5460622.22519.446247/8-10UNS 10 1.513 2.542A 22.1792821.8516220.5282820.3758819.156682B 19.481820.015220.57420.7721222.22519.842487/8-12UN121.262.1172A 22.1818221.8922620.8076820.6679819.662142B 19.93920.396220.8508621.0337422.22520.241263A22.22521.9354420.8508620.7467219.705323B 19.93920.1879220.8508620.9880222.22520.241267/8-14UNF141.0811.8141A22.1843621.7906621.005820.8000620.025361B20.269220.675621.0464421.3156822.22520.63750.8125"20.638螺纹小径螺纹外径MaxMinMax MinMaxMin Max MinMaxMin 公称直径螺纹规格牙数牙高螺距公差代号螺纹外径钻孔直径螺纹中经公差代号螺纹小径螺纹中径2A 22.1843621.9227421.005820.8686420.025362B 20.269220.675621.0464421.2242422.22520.63753A22.22521.9633821.0464420.942320.0663B 20.269220.4927221.0464421.1810622.22520.63757/8-16UN160.861.5882A 22.186921.9481421.1556621.031220.0662B 20.497820.853421.1937621.3537822.22520.63753A22.22521.9862421.1937621.1023220.33273B 20.497820.7213221.1937621.3131422.22520.63757/8-18UNS 180.841 1.4112A 22.1894421.9684621.272521.1556620.51052B 20.70121.031221.3080621.4604622.22521.033747/8-20UNEF200.7561.272A 22.1919821.9862421.3664821.2547220.680682B 20.853421.132821.399521.5442822.22521.033743A22.22522.0192621.399521.3156820.71373B 20.853421.0489821.399521.5087222.22521.033747/8-24UNS 240.63 1.0582A 22.1945222.0116421.5061821.4020420.934682B 21.08221.33621.5366621.6712822.22521.033747/8-27UNS 270.560.9412A 22.1945222.0243421.5823821.4833221.074382B 21.20921.437621.6128621.742422.22521.429987/8-28UN280.540.9072A 22.1945222.0294221.6052421.5087221.112482B 21.234421.46321.6357221.7627222.22521.429983A22.22522.059921.6357221.5620621.142963B 21.234421.4020421.6357221.729722.22521.429987/8-32UN320.4720.7842A 22.1970622.0446621.6814421.5921.252182B 21.361421.564621.7093821.8287622.22521.429983A22.22522.072621.7093821.640821.280123B 21.361421.5112621.7093821.8008222.22521.4299815/16-9UNC91.682.8222A 23.7693223.4162621.9354421.7754220.40892B 22.136121.348721.9786222.186923.812521.033743A23.812523.4594421.9786221.8592420.452083B 22.136121.0972421.9786222.1335623.812521.0337415/16-12UN121.262.1172A 23.7693223.4797622.3951822.250421.249642B 21.513821.97122.4383622.6263223.812521.828763A23.812523.5229422.4383622.3342221.292823B 21.513821.780522.4383622.5780623.812521.8287615/16-16UN160.861.5882A 23.774423.5356422.7431622.6161621.88212B 22.09822.453622.7812622.9463623.812524.7653A23.812523.5737422.7812622.6872821.92023B 22.09822.3088222.7812622.9057223.812522.22515/16-20UNEF200.7561.272A 23.7769423.571222.9514422.8371422.265642B 22.428222.73322.98723.1368623.812522.2253A23.812523.6067622.98722.9006422.30123B 22.428222.6364822.98723.0987623.812522.22515/16-28UN280.540.9072A 23.7820223.6169223.1927423.0911422.699982B 22.834623.037823.2232223.355323.812523.017483A23.812523.647423.2232223.1470222.730463B 22.834622.9895423.2232223.3222823.812523.0174815/16-32UN320.4720.7842A23.7845623.6321623.2689423.1724222.839682B22.961623.139423.2968823.4213423.812523.017480.875"22.2250.9375"23.813。
美制螺纹标准对照表
5/8-18
3/4-16
7/8-14
1"-12
1.底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、青铜等较硬料取大值。
2.标记示例：10-32UNF-2B(或、3/8-24UNF-2B(或
2.标记示例：10-24UNC-2B(或、3/8-16UNC-2B(或
美制内螺纹（2B）常用规格极限尺寸表（细牙）
公称尺寸和每英寸牙数
螺纹系列代号
小径极限
中径极限
大径min
底孔直径
最小
最大
最小
最大
最小
最大
8-36
UNF
10-32
12-28
1/4-28
5/16-24
3/8-24
7/16-20
1/2-20
美制内螺纹（2B）常用规格极限尺寸表（粗牙）
公称尺寸和每英寸牙数
螺纹系列代号
小径极限
中径极限
大径min
底孔直径
最小
最大
最小
最大
最小
最大
8-32
UNC
/16-18
3/8-16
7/16-14
1/2-13
9/16-12
5/8-11
3/4-10
7/8-9
1"-8
1.底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、青铜等较硬料取大值。
1.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。
2.标记示例：10-24UNC-2A(或、3/8-16UNC-2A(或
（注：表中上行斜体数值单位为英寸，下行为毫米）
美制外螺纹（2A）常用规格极限尺寸表（细牙）
公称尺寸和每英寸牙数
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5/8-18
3/4-16
7/8-14
1"-12
1.底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、青铜等较硬料取大值。
2.标记示例：10-32UNF-2B(或、3/8-24UNF-2B(或
精心搜集整理，只为你的需要
1.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。
2.标记示例：10-24UNC-2A(或、3/8-16UNC-2A(或
（注：表中上行斜体数值单位为英寸，下行为毫米）
美制外螺纹（2A）常用规格极限尺寸表（细牙）
公称尺寸和每英寸牙数
螺纹系列代号
大径极限
中径极限
小径max
螺胚直径
最小
2.标记示例：10-24UNC-2B(或、3/8-16UNC-2B(或
美制内螺纹（2B）常用规格极限尺寸表（细牙）
公称尺寸和每英寸牙数螺纹ຫໍສະໝຸດ 列代号小径极限中径极限
大径min
底孔直径
最小
最大
最小
最大
最小
最大
8-36
UNF
10-32
12-28
1/4-28
5/16-24
3/8-24
7/16-20
1/2-20
美制螺纹标准对照表
美制外螺纹（2A）常用规格极限尺寸表（粗牙）
公称尺寸和每英寸牙数
螺纹系列代号
大径极限
中径极限
小径max
螺胚直径
最小
最大
最小
最大
最小
最大
8-32
UNC
10-24
12-24
1/4-20
5/16-18
3/8-16
7/16-14
1/2-13
9/16-12
5/8-11
3/4-10
7/8-9
1"-8
最大
最小
最大
最小
最大
8-36
UNF
10-32
12-28
1/4-28
5/16-24
3/8-24
7/16-20
1/2-20
9/16-18
5/8-18
3/4-16
7/8-14
1"-12
1.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。
2.标记示例：10-32UNF-2A(或、3/8-24UNF-2A(或
美制内螺纹（2B）常用规格极限尺寸表（粗牙）
公称尺寸和每英寸牙数
螺纹系列代号
小径极限
中径极限
大径min
底孔直径
最小
最大
最小
最大
最小
最大
8-32
UNC
10-24
12-24
1/4-20
5/16-18
3/8-16
7/16-14
1/2-13
9/16-12
5/8-11
3/4-10
7/8-9
1"-8
1.底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、青铜等较硬料取大值。