螺纹拧紧力矩计算

螺纹联接的拧紧力矩计算

M t＝K×P0×d×10－3 N.m

K:拧紧力系数d：螺纹公称直径

P0：预紧力

P0＝σ0×A s A s也可由下面表查出

A s＝π×d s2/4 d s:螺纹部分危险剖面的计算直径

d s＝（d2＋d3）/2 d3= d1－H/6 H：螺纹牙的公称工作高度

σ0＝（0.5～0.7）σs σs――――螺栓材料的屈服极限N/mm2（与强度等级相关，材质决定）K值查表：(K值计算公式略)

K值

摩擦表面状况

有润滑无润滑

精加工表面0.10 0.12

一般加工表面0.13~0.15 0.18~0.21

表面氧化0.20 0.24

镀锌0.18 0.22 干燥的粗加工表面 0.26~0.3 σs查表：

螺纹性能等级 3.6 4.6 4.8 5.6 5.8 6.88.89.810.912.9

σs 或σ0.2N/mm21802403203004004806407209001080

As查表：

螺纹公称直径d/mm3 3.545678101214161820222427303336公称应力截面积As/mm2 5.036.788.7814.220.128.936.65884.3115157192245303353459561694817通过计算得到螺栓联接拧紧力矩如下表所示：

表面被氧化（无润滑）的螺纹联接的拧紧力矩值（单位：N.m）

性能

等级 3.6 4.6 4.8 5.6 5.8 6.88.89.810.912.9

螺纹

直径

d/mm min max min max min max min max min max min max min max min max min max min max 30.330.460.430.610.580.810.540.760.72 1.010.87 1.22 1.16 1.62 1.30 1.83 1.63 2.28 1.96 2.74 3.50.510.720.680.960.91 1.280.85 1.20 1.14 1.59 1.37 1.91 1.82 2.55 2.05 2.87 2.56 3.59 3.08 4.31 40.76 1.06 1.01 1.42 1.35 1.89 1.26 1.77 1.69 2.36 2.02 2.83 2.70 3.78 3.03 4.25 3.79 5.31 4.55 6.37

5 1.53 2.15 2.04 2.8

6 2.73 3.82 2.56 3.58 3.41 4.7

7 4.09 5.73 5.457.63 6.138.597.6710.749.2012.88

6 2.60 3.65 3.4

7 4.86 4.63 6.4

8 4.34 6.08 5.798.10 6.959.739.2612.9710.4214.5913.0218.2315.6321.88

7 4.37 6.12 5.838.167.7710.887.2810.209.7113.5911.6516.3115.5421.7517.4824.4721.8530.5926.2236.71

8 6.328.858.4311.8111.2415.7410.5414.7614.0519.6816.8723.6122.4931.4825.3035.4231.6244.2737.9553.13 1012.5317.5416.7023.3922.2731.1820.8829.2327.8438.9833.4146.7744.5462.3650.1170.1662.6487.7075.17105.24 1221.8530.5929.1340.7938.8554.3836.4250.9848.5667.9858.2781.5877.69108.7787.40122.36109.25152.95131.10183.54 1434.7848.6946.3764.9261.8286.5557.9681.1477.28108.1992.74129.83123.65173.11139.10194.75173.88243.43208.66292.12 1654.2675.9672.35101.2896.46135.0590.43126.60120.58168.81144.69202.57192.92270.09217.04303.85271.30379.81325.56455.78 1874.65104.5199.53139.35132.71185.79124.42174.18165.89232.24199.07278.69265.42371.59298.60418.04373.25522.55447.90627.06 20105.84148.18141.12197.57188.16263.42176.40246.96235.20329.28282.24395.14376.32526.85423.36592.70529.20740.88635.04889.06 22143.99201.58191.98268.77255.97358.36239.98335.97319.97447.96383.96537.55511.95716.73575.94806.32719.931007.90863.911209.48 24183.00256.19243.99341.59325.32455.45304.99426.99406.66569.32487.99683.18650.65910.91731.981024.77914.981280.971097.971537.16 27267.69374.76356.92499.69475.89666.25446.15624.61594.86832.81713.84999.37951.781332.501070.761499.061338.441873.821606.132248.59 30363.53508.94484.70678.59646.27904.78605.88848.23807.841130.98969.411357.171292.541809.561454.112035.761817.642544.702181.173053.64 33494.68692.56659.58923.41879.441231.21824.471154.261099.301539.011319.161846.821758.872462.421978.732770.232473.423462.782968.104155.34 36635.30889.42847.071185.891129.421581.191058.831482.361411.781976.491694.132371.782258.843162.382541.203557.683176.504447.093811.805336.51