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Greater Pull-Out Force: 10-32 or 10-24

Greater Pull-Out Force: 10-32 or 10-24

Greater Pull-Out Force: 10-32 or 10-24

(OP)
Which Thread would provide greater resistance to pullout: 10-24 or 10-32?

10-24 would give you fewer threads that are coarser.
10-32 would give you more threads that are finer.

We are tapping into a thin sheet of stainless steel.

Thanks for the help.

RE: Greater Pull-Out Force: 10-32 or 10-24

How thin? A 1/16" thick plate would only catch 1 1/2 threads at 10-24 and 2 treads at 10-32. Neither will hold much force.

Timing has a lot to do with the outcome of a rain dance.

RE: Greater Pull-Out Force: 10-32 or 10-24

Are these fasteners self-drilling?

The question is moot.  If you are relying on sheet metal screws in thin sheet metal to resist axial loads, you will be disappointed.  A simple physical test of these components will provide the actual values and prove the point.

RE: Greater Pull-Out Force: 10-32 or 10-24

(OP)
The sheet metal is only ~1/16" thick.
We are tapping out the hole firts.

2 screws are being used to attach a handle to a metal part that only weighs about 1-2 pounds.

So it works ok for the load. I was just wondering if we would get better results with the coarser or finer thread.

As paddingtongreen states, we can only get 1-1/2 to 2 threads. But do you think it would be better to have 1-1/2 coarse threads or 2 fine threads.

Thanks

RE: Greater Pull-Out Force: 10-32 or 10-24

10-24 will hold better.

RE: Greater Pull-Out Force: 10-32 or 10-24

A properly tapped hole includes a chamfer, so the working thread length is probably even less than 1/16". Depending on what the "handle" and "part" are used for, and how often they are used, there may be some issues that are not revealed at assembly, or even during funtional tests, but will be the topic of serious conversations next year

I'd test several samples through a lifetime of cycles at the anticipated working load, twice the working load, then using the part to manually crush one hundred pounds of ice cubes on the kitchen counter. Then I'd feel like the "expert."

RE: Greater Pull-Out Force: 10-32 or 10-24

Odd that you want to tap the hole - For a thin steel piece - it's not really thick enough to be called a "plate" at 1/16 inch - you would actually get much more engagement area with a self-tapping (stainless steel) sheet metal screw.  

No hole to drill.  (Or a pre-hole the diameter of the sheet metal screw shank)
No tapping expense and time and setup.  
No tapping machinery, or badly threaded holes.
No rework.
Wider threads on a sheet metal screw than on either a 10-32 or 10-24.

Alterate:  Use a car body type clip with attached nut.  Nutcert (I think) is a supplier.   Better engagement, cheaper, faster, stronger.  (Not as elegant looking.)

RE: Greater Pull-Out Force: 10-32 or 10-24

There is a great selection of captive nuts for use with thin stainless steel sheet. We also extrude holes in thinner sheets to increase the pullout. You can easily get 2x material thickness with extruded holes.  

RE: Greater Pull-Out Force: 10-32 or 10-24

Why not use PEM nuts?

V

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