一、固定成型螺距误差的影响介绍挤压丝锥的资料,几乎都列出了锥棱过渡区螺纹的固定成型螺距误差Δt的计算式。这项Δt误差,已经超过切削丝锥允许的螺距累计误差一倍左右。而且,随螺距与锥角的增加而变大。就M2.5—2规格丝锥而言,切削丝锥允许累计误差单向值是0.012;挤压丝锥锥部斜角φ=12°时,计算Δt的单向值是0.025。机床刚性不足、精度不高或轴精向间隙大时,实际Δt First, the impact of fixed-forming pitch error Introduction to the information on the extrusion tap, almost all listed cone-edge transition zone fixed thread forming pitch error Δt formula. This Δt error has exceeded the allowable pitch pitch error of the cutting tap about one time. Moreover, with the pitch and cone angle increases. For M2.5-2 taps, the allowable unwinding error of the cutting tap is 0.012. When the bevel angle φ = 12 ° of the tap, the unidirectional value of Δt is 0.025. Insufficient rigidity of the machine, the accuracy is not high or when the shaft to the gap, the actual Δt