|John Rutzen||13/02/2019 12:41:10|
|78 forum posts|
Hi just a hint I thought I would pass on after wasting an hour today trying to thread some 8 BA studs. I was trying to grip 3/32 stainless, first in a chuck- no good, it wouldn't grip it. Then I tried a collet, worked but with difficulty. Then the die wouldn't cut the thread. I remembered then that I had 50 stainless steel M2.5 screws I had bought on eBay for very little money. They fitted the 3/32 holes in my Lion frames just great. The problem is the nuts are big and ugly but you can tap out 8BA nuts to M2.5 no bother. So problem solved. It works very well too with M3 cheap screws and tapped out 6BA nuts.
15321 forum posts
You can buy smaller hex head metric fixings from Polly and GHW which look more in keeping
|John Haine||13/02/2019 13:48:29|
|2500 forum posts|
A tip which might work for threading out small nuts - I have used it to drill out M2 nuts to make short spacers.
Chuck a socket that fits the hax in your 3 jaw or better a collet. Stack a row of the nuts into the hex and feed the drill into the threaded hole in the tailstock. As each nut gets drilled out it slides on to the drill. You can do as many as will fit in the socket in one go.
To thread I guess you'd drill out like this if needed, then put the nuts back in the socket and feed in the tap.
|Clive Brown 1||13/02/2019 14:55:52|
|229 forum posts|
3/32" dia. material is a bit big for an 8BA die, especially stainless. 7BA would be a better thread which I've often used in conjunction with 3/32 dia. rod.
|John Rutzen||13/02/2019 15:16:53|
|78 forum posts|
Hi, yes I tried turning it down to 2.2mm but still found I couldn't get the die to go on well. Maybe my die isn't quite what it should be. I wasn't suggesting buying 8BA nuts and re-threading them , it's just that I had about 200 of them from decades ago when they were cheap. The re-threaded 8BA nuts look very neat with the M.5 studs.
|thomas oliver 2||11/04/2019 20:01:19|
|102 forum posts|
Blunt dies are relatively easy to sharpen. Fit a grinding burr into your Dremel or drill which is slightly smaller than one of the holes. Figure out which is the cutting edge and run the burr through a few times. You can see the fresh surface which is ground and continue until it reaches the cutting edge. Repeat for other edges. Tapas can also be easily sharpened. A conical burr is best - fractionally less in radius than the flute radius.or the same. The trick is to run the burr in each flute TOWARDS the tip, then if it jumps it will not damage the cutting edge..The other way up, one slip and the tap is ruined.
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.