Bolt Tigh­tening Torque Chart + Calcu­la­tor: Stan­dard Bolt Sizes at a Glance (Guide 2025)

Screw and Bolt Torque Table for Stan­dard Threads

The recom­men­ded tigh­tening torques below are a great start­ing point for figu­ring out how much torque you need.

This Chart gives the suggested maxi­mum torque values for threa­ded products, but it’s just a reference.

Bolt torque calculator

Select thread size and bolt grade to display the tigh­tening torque for stan­dard threads in [Nm].

What is torque?

Torque is a physi­cal force that indi­ca­tes how stron­gly a rota­tio­nal move­ment affects an object.

To calcu­late the torque (M) in Newton meters [N m], you will need the force (F) in Newtons [N] and the lever arm distance (l) measu­red perpen­di­cu­lar to the line of action in meters [m].

The direc­tion of the torque is indi­ca­ted by + (coun­ter­clock­wise) and — (clock­wise).

What strength clas­ses are there?

The strength clas­ses of screws deter­mine their tensile strength {R_m} and yield strength {R_e}.

In this repre­sen­ta­tion, the left number signi­fies the tensile strength, and the right number repres­ents the yield strength.

Thanks to the various number combi­na­ti­ons, diffe­rent types of bolts can be compared with each other.

How to calcu­late tensile strength?

To calcu­late tensile strength, simply multi­ply the left number of the strength class by 100.

How to calcu­late yield strength?

To calcu­late yield strength, multi­ply the left and right numbers, and then multi­ply the result by 10.

Table of strength clas­ses of bolts

The follo­wing table includes all the strength clas­ses mentio­ned in the screw torque table, along with their corre­spon­ding tensile strength and yield strength.

Which strength class suits which screw?

Screws made of alumi­num, stain­less steel, and tita­nium possess diffe­rent proper­ties due to their distinct mate­ri­als.

The follo­wing table is inten­ded to assist in assig­ning them to their respec­tive strength classes.

FAQ

When does a screw break?

When the permis­si­ble yield strength is excee­ded, the screw begins to deform, even­tually leading to the brea­king of the screw.

What is the torque for steel rims?

The correct torque for the wheel bolts of a steel rim on a vehicle can be found in the vehicle manual. Howe­ver, it usually ranges between 80 and 160 Newton meters.

How much N m can be applied by hand?

Using a screw­dri­ver, a mini­mum torque of 30 N m can be achie­ved. The longer the lever, the grea­ter the force that can be applied.

Which screws should be tigh­tened with how much N m?

To find out which screws should be tigh­tened with how much torque, it’s worth taking a look at the screw torque table depic­ted above. There, screws with their respec­tive strength clas­ses and corre­spon­ding torques can be easily read.

Where do I find the tigh­tening torque?

Normally, each manu­fac­tu­rer speci­fies the permis­si­ble tigh­tening torque of the screws on the pack­a­ging. If that’s not the case, it can be found in a screw torque table.

Why do I need a torque test­ing device for nutrunner?

Torque test­ing devices verify the accu­racy of torque wren­ches, elec­tric nutrun­ner, and cord­less nutrun­ner so that they can be cali­bra­ted accordingly.