We’ve all been there – you’re working on a project and wondering how much to torque something so either we don’t bother or just take a guess. What I only found out recently was that in 2017, NASA published a really cool guide called “Installation Torque Tables for Noncritical Applications” – with the document ID as NASA/TM—2017-219475.
The document provides the torque specifications for a ton of general purpose fasteners that do not have an exact specification assigned – hence the term non-critical. As you can imagine, they get very specific in critical/risky situations.
At any rate, given the size of the bolt or screw, the thread pitch, the material and the depth, they provide a reference torque specification you can follow for both metric (M6, M8, M10, etc.) and SAE (#8, #10, 1/8, 1/4, 3/8, etc.) fasteners. Note, they provide an assembly torque (which is a 65% load from failure) and 100% torque. I use the assembly torque spec.
They also recommend that the depth of thread engagement be 1.5x the diameter of the fastener. So a 1/4″ (0.25″) fastener should have at least 0.25″ x 1.5 = .375″ (3/8″).
Kudos to the two authors and to NASA for making it available. The PDF is a cool reference document and one I use whenever I can’t find a specific torque value for a given application. All you machinists and engineers – you know way more than me so please let me know if you have other resources you recommend.
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