I'm using a couple of pieces of 3/4" rod to make pins for a project. They screw into an underlying part throughan upeer piece with with thier tops flust to the surface of the upper part. I need a way to screw them in, seems like a hex socket wouls work best, or maybe a 1/4 or 3/8 square sochet would do it>
I only have two of these to do so I don't wan't to invest $$$ in a "real" broach, anyone here had any luck using an old hex key as a broach?
Anyone got a better idea?
Thanks,
H.
How about drilling/countersinking and threading a hole in the rod, then epoxy a flathead allen screw in?
Another solution is to face the rod, and drill three axial blind holes in an equilateral pattern, just a little oversize of 1/8". Then make a wrench with three holes 0.126", with short .125" dowel pins inserted. Two-pin wrenches are more common, but the three-pin variety has better stability...
Pin spanner, just two simple holes to mill.
Another idea: just cut a slot for a large screwdriver.
I broached the hex hole for the adjusting screw with an Allen wrench ground flat on the end:
I think that steel soft enough to broach is too soft to withstand much tightening, which isn't an issue for the adjusting screw here. For a fastener I'd go with the suggested slot or two dowel pin spanner and make the wrench from the same diameter stock in the same fixture setup.
jsw
Howard Eisenhauer wrote in rec.crafts.metalworking on Sat, 02 Jul 2011 23:06:56 -0300:
No, use a new one. Cut and face the end square, then using a carbide drill or lathe bit, make a slight dish on the face.
Drill a hole in your workpiece slightly larger than the across flats size of your hex broach. Counter sink to larger than your across points of the hex broach.
not as good as a real broach, but it can work.
The concave end might make it cut more easily but a flat or slightly convex end should help the tool stay centered. If it doesn't cut you can easily regrind it.
jsw
Won't work.... unless you have an undersize key to go into the on-size hole.....
How about something really high tech and elaborate.... like a slot....
I've done it a number of times with a hex key ground flat on the end and pressed in with a press and the range of materials was stainless steel, steel, and brass. When I've used a hex key rather than milling a hex broach I try and pick a key that's slightly oversize or make sure I have a key that is slightly smaller to use in the hex socket. You could also try finding a close metric or inch key slightly larger for use as the broach.
A 1/8" Allen wrench fits the socket in my boring head easily. I think I just wiggled the broaching wrench to open up the hex socket a bit.
jsw
Thanks for all the input folks. I did the chopped off allen key trick & it worked like a charm :) I chucked the pins into the lathe & ran the "broach" in with the tail stock. This was actually easier for me to do than trying to cut a decent slot in the ends or tapping/coutersinking for an allen head screw (which I don't have any handy anyhow :()
FYI the only key I had avaialble to sacrifice of course turned out to be smaller than the any of my good ones but tapping & wiggling the biggest one I had into the holes opened them up nicely.
H.
=========== You might want to consider modifying a stripper/shoulder bolt by turning the head down to body diameter.
For an example see
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