式中：n—螺纹有效圈数；[τ]—需用剪切强度，Mpa；S—一个螺距螺纹

式中：<br>n—螺纹有效圈数；<br>[τ]—需用剪切强度，Mpa；<br>S—一个螺距螺纹的剪切面积，mm2；<br>其中由于连接套采用的材料为4140，其最低屈服强度σ_s=930Mpa。其中为了安全选用较高的安全系数n=1.5，有

Where:<br>N - number of effective turns of thread;<br>[ τ]— Required shear strength, MPa;<br>S - shear area of one pitch thread, mm2;<br>Because the material of the connecting sleeve is 4140, its minimum yield strength is σ_ s=930Mpa。 For safety, a higher safety factor n = 1.5 is selected, including:

Type: N-effective number of turns of thread; [τ]-required shear strength, Mpa；; S-shear area of one pitch thread, mm2；; Because the connecting sleeve is made of 4140 material, its minimum yield strength σ _ s σ_s=930Mpa. Among them, a higher safety factor n=1.5 is selected for safety, and there are