mechanical calculators

Screw Torque Calculator

Calculate required torque for screw fastening

About this calculator

The Screw Torque Calculator determines the optimal torque value needed to properly fasten screws and bolts in mechanical assemblies. This tool helps engineers, technicians, and DIY enthusiasts ensure secure connections without over-tightening, which can damage threads or under-tightening, which compromises joint integrity. By calculating precise torque requirements based on screw specifications and material properties, users can achieve consistent, reliable fastening results while preventing costly failures or rework.

How to use

Enter the screw diameter, thread pitch, and material specifications into the calculator. Select the desired safety factor and friction coefficient based on your application requirements. The calculator will instantly compute the recommended torque value, ensuring optimal fastening strength for your specific screw and assembly conditions.

Frequently asked questions

What factors affect screw torque requirements?

Screw diameter, thread pitch, material strength, friction coefficient, and desired clamping force all influence the required torque value for proper fastening.

How does over-torquing damage screws?

Excessive torque can strip threads, stretch the screw beyond its elastic limit, or cause stress concentrations leading to premature failure.

What is the typical friction coefficient for steel screws?

Steel-on-steel friction coefficients typically range from 0.1 to 0.2, depending on surface finish, lubrication, and thread coating conditions.