Has anyone got a single 2" long 5/8" BSF grub screw I can exchange for currency? My local (usually pretty good) fastenings stockist is unable to come up with the goods. If I really have to I can die sink a hex socket into a bit of HT 5/8" BSF studding cut from a bolt (that I'll have to buy from them) but I'd rather not as it means the bore of making a tool.
(This is a pivot adjusting screw on an Edwards 4 foot x 14 gauge box pan folder I am resurrecting)
I recently made two brass carb jets that need a hex recess and tight-fitting key to hold them in place while being installed. The tooling I made to broach the hex consisted of a 6-hole sheet metal index disk bored to fit my lathe's spindle thread, secured by the collet holder removal nut, and a hex key one size smaller ground flat on the end.
I held the disk in each of the 6 positions with a cobbled-up index pin made from brazing rod and broached out the hex at 0.001" per hand-fed cut with the sharpened hex key in a boring bar holder. The key cuts with the angle that's toward the operator and set to center height. After a few passes all around I ran in the shop-made 90-degree-point D bit, which originally formed the recess and the lead-in to the metering hole, to knock off the shavings.
6 index holes around a circle is very simple to step out with dividers still set to the radius of the circle, in case you've forgotten your Euclid.
If I hadd put a hex socket into a 5/8 screw I would tap the end of the screw and use a 7/16 or 3/8 set screw threaded into the larger screw and retained with Loctite. Eric
If the chosen high tensile steel is too difficult to tap, maybe you could machine or grind a male hex section on the end and use a modified socket head cap screw for the wrench. Then you could shape it with a carbide flycutter and not risk a more delicate and expensive tool. jsw
Thanks chaps for the suggestions, but if I end up having to put a hex recess into the end of the HT stud, I will use my die sinker EDM machine as the tooling just needs to be a copper or graphite hex with a hole down the middle for flushing. I might even get away for a one off with a bit of hex brass bar :)
"Andrew Mawson" wrote in message news: snipped-for-privacy@bt.com...
Nice that you have it. We have to make assumptions when someone asks how to do a simple operation, such as that they are an amateur with only a hobbyist lathe and/or mill. I have a surface grinder but rarely suggest an answer that needs one. jsw
Thanks Jim. Most of the people on this newsgroup know me as I've been here for rather a long time. (15-20 years) The problem comes when people come via google groups and think that it is a forum :)
Well I don't know why I didn't suggest just pulling out your EDM. I mean that's what I would do . If I had an EDM machine. EDM would make a nice and easy job for making the female hex shape. Cheers, Eric
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