Bolt shear strength

Ken&Laura Chaddock snipped-for-privacy@hfx.eastlink.ca

wrt bolt vs screw

From Machinery's Handbook, 21st Edition, page 1131:

Distinction without difference, perhaps?

If you take a hex-headed 1/2 in rod, threaded some length for 13 tpi, and use it with a nut to secure two pieces of material, its a bolt. If you remove the bolt, toss the nut, and use the rod alone to secure two pieces of material, one of which is threaded to 1/2- 13, now its a screw.

Reminds of the "distinction" between mandril and arbor. FM

Not misleading. The fact is aerospace fastener specs refer to fully threaded fastners as screws and fasteners with unthreaded shanks as bolts. Applications for both types of fasteners can overlap.

The heads on screws and bolts are both under compression for preloaded joints. You are correct as far as moving parts and applying torque.

"Jonathan Barnes" snipped-for-privacy@ATnetcomuk.co.uk

I. There's no reason you can't have a set screw with a "shank" (unthreaded portion of its length).

And

II. The carriage bolts I'm familiar with (New England) have a round head under which there is a short, squared length, with no point at the threaded end. (There's also a varient on theme called the "lag screw," which has not been mentioned yet in this thread.)

And

III. I agree. This discussion is about usage, which is never screwed down tight. "Bolt" and "screw" are generic terms; they have multiple meanings that won't be pinned down by MH or some trade text.

Frank Morrison

In England, a set screw is always fully threaded .

-- Jonathan

Barnes's theorem; for every foolproof device there is a fool greater than the proof.

To reply remove AT

Dear Jonathan Barnes:

A short search comes up with this UK site:

Everyone's hands are dirty, apparently.

David A. Smith

Sure set screws generally are full threaded. But the point above is that a set screw CAN have an unthreaded shank. Certain application may require a 'bolt' type set screw.