Suggestions needed on how to create thread interference on 6-32 screw

Needed: Many thousands of 6-32 screws in which a 6-32 hex nut will only screw on up to a desired thread distance and no more.

1's or 2's I can do with a side cutter, etc.

I am thinking spot welding an imperfection on the thread or using a hammer or a press do slam ears or grooves.

Any experience along these lines?

Reply to
BoyntonStu
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For "many thousands" I would have them made with the correct amount of thread.

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Reply to
David Courtney

Many thousands - order them with threads that only go as far as you want?

Otherwise, yes, a mechanical deformation should work. Welding seems a bit iffy - crappy welds don't stick well, more extensive welds will probably warp the screw.

Reply to
Ecnerwal

No experience, but here's what I'd do...

Start with a small block of metal, drill a clearance hole for the screw, and a guide hole at right angles for a punch/swage. Make up and harden a punch to go through the guide hole and suitably bugger the threads. Clamp the block in an arbor press with the ram pushing the punch. Loose the workerbees on it.

Reply to
Jim Stewart

Great IF a custom shop can do them for ~ 1 cent each plus the cost of deformation.

Reply to
BoyntonStu

Do you think that more than 1 at a time could be buggered?

If so, would multiple holes or a slot be a good jig design?

I can 'see' a horizontal slot, screws sitting on their heads, riding vertically along on the slot, threads hanging down.

A 'pincer' tool at the appropriate thread height whose jaw come together horizontally is powered by a horizontal action arbor foot press or a ram.

What say you?

A problem might arise in feeding the stock screw and removing it when it has been buggered.

Reply to
BoyntonStu

I'm sure I could design something, but not in

5 minutes or for free (:

More than one at a time becomes a serious project.

Reply to
Jim Stewart

Similar, but faster, I think: same block with clearance hole - screw bottoms in hole, leaving enough exposed to grasp. same right angle hole for punch. Punch sits on a spring to keep it withdrawn.

To use: insert screw, hit punch with hammer, withdraw screw. Cycle time of 1.5 sec +-.

Bob

Reply to
Bob Engelhardt

Jim Stewart wrote in news:bfqdnc3AyMuW3dLanZ2dnUVZ snipped-for-privacy@omsoft.com:

100% agree. But the op really hasn't stated enough information to even do a concept from. My first thought....if you pinch/damage/dent the screw...you've just created the ideal place for it to fail prematurely.

Agreed, it also means much more $$$.

Reply to
Anthony

There's all that. Suggestions are free and low risk. Signing my name on a drawing is a different thing.

Reply to
Jim Stewart

run the nut into position and apply a drop of locktite.

or you need to make a little press to crunch a shape that the nut cant go past.

Reply to
Stealth Pilot

Reverse the sequence, put the dab of Loctite on first. You can buy screws with a drop of threadlocker preinstalled although I don't know the placement accuracy. Segways are assembled with them. The screw doesn't quite stop dead when it hits but you can't turn them by hand any more. With the stronger grades you need heat and Vise-Grips to get the screw out afterwards.

Reply to
Jim Wilkins

If the screw is first buggered you can supply the screws and nuts separately.

No wasted time/effort threading nuts onto screws.

Precise positioning (within a single thread ~ 0.013") is important.

Reply to
BoyntonStu

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