1/4 20 one end threaded studs - Stainless

I already looked on McMaster and The closes they have is too long, and at

19.59 each way to expensive.

I have been buying generic stainless bolts at the local box store and cutting them off with my flexshaft and a fiber wheel, but I was kinda hoping to find some small boxes for a reasonable price. One less little thing to eat up time, and maybe have a nicer edge without grinding on the non threaded end. 3/4 length with 3/8 threaded is what I am hoping to find.

At the price from McMaster even counting my time its cheaper to buy bolts and cut them off... and the ones from McMaster would still need to be cut off.

Suggestions? Or should I just continue to throw bolts in my vise and cut them off as needed? Most common alloys are ok. They are just being used for alignment pins screwed into aluminum molds. No stress on the pins. I could use a little smaller (diameter not length) ones if the price was right.

I'ld like to buy about 50 at a time for common stainless bolt prices.

Reply to
Bob La Londe
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How about a jig that goes in the mill vise? Drop in bolt, tighten vice, traverse mill with a slitting saw in the spindle. I'll bet it wouldn't take 10 seconds per bolt to behead them once you got rolling.

Reply to
Don Foreman

That may wind up being the best option. Make up a bunch of alignment pins as a separate project.

Reply to
Bob La Londe

I use a parting tool in the lathe, then chamfer.

Richard W.

Reply to
Richard W.

On Sun, 20 Jun 2010 22:26:46 -0500, Don Foreman wrote the following:

Or a pneumatic vise jigged into a 4x6 bandsaw. Cut 'em off and run 'em through the grinder for a smoother chamfered edge.

Bob, have you asked a CNC Swiss screw shop for prices on such? In larger quantities, it might be far cheaper.

-- Peace of mind is that mental condition in which you have accepted the worst. -- Lin Yutang

Reply to
Larry Jaques

Check with Fastenal Industrial Supplies Steve

Reply to
Steve Lusardi

Just out of curiosity, why can't you use 50 cent SS dowel pins and press them in to one side, with a larger hole on the other side?

Reply to
Spehro Pefhany

I don't reckon there is any reason I can't. I just had not thought of it. I center punch my holes on the mill while machining and drill them out two different sizes already on the drill press now. No different I guess to do the same thing for a press in pin. Aluminum does expand and contract quite a bit with heat and these molds routinely go from room temp to having 300F+ plastic shot in them and then after the run is done cool back to room temp.

Reply to
Bob La Londe

I had not thought of Fastenal. They even have a local store front. I had already planned to check Copperstate Bolt. I'll check Fastenal too.

Reply to
Bob La Londe

CTE for aluminum is 23E-6/°C and for SS it's 17.3E-6/°C according to Wikipedia.

So the mismatch is 5.7E-6/°C. The differential expansion in a 0.25" pin for 100°C change would be 0.14 thou. That doesn't sound too bad, less than 10% of your typical 0.002" interference fit.

Reply to
Spehro Pefhany

Thank you. My next post was going to be to ask the information you just provided. Not only did you answer, you told me how to look up similar information for myself in the future. Thank you very much. Now if only the sometimers doesn't kick right before the next time I have to worry about heat expansion.... LOL.

Reply to
Bob La Londe

Well, I decided to give press fit pins a try. Neither Fastenal nor Copperstate Bolt had any in stock in the local stores. They both list them on their website. I guess its time to see what Google says is available.

Reply to
Bob La Londe

What's that Lassie? You say that Larry Jaques fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Mon, 21 Jun 2010 06:23:47 -0700:

This kind of thing would only take about 25sec each on a swiss lathe. Less than an hour to setup and program.

Reply to
dan

Are you making "alignment pins"? If so why not just use straight pins and press them in? That is how most pins used only for alignment are installed.

Cheers,

John D. Slocomb (jdslocombatgmail)

Reply to
J. D. Slocomb

McMaster has lots. Eg. 90145A540 $10 for 20 pieces in 18-8 SS.

I assume you have matching reamers for the two hole sizes.

Reply to
Spehro Pefhany

Well no, but for this application precision is not mandatory. I figured I'ld just keep drilling the 1/4 hole and improvise for the smaller hole. I didn't find the 18-8 1/4 by 3/4 for that on McMaster. The one I found sure looked like $20 each. Amazon listed a seller with them for about 25¢ each in bags of 25. 4 bags was $38 including priority shipping. I have also considered aluminum pins. Easy to cut to length and a tiny little spot weld on the back to hold them in place. Only problem with aluminum pins is that they will wear out more quickly.

Reply to
Bob La Londe

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