Need 5/16-22 socket head screws

Subject says it all, I need to find at least 3 5/16-22 allen head cap
screws, about 1.5" long. I do NOT need 5/16-24 screws and this is not a
misprint, I really need 5/16-22. I think it is some english size, it's
to fit the back of an english 3-jaw lathe chuck.
Reply to
Nick Hull
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Nick, is it possible that this is an 8mmX1.25 thread pitch metric screw?
RJ
Reply to
Backlash
5/16-22 would be 5/16 BSF (British standard fine), Can't help with suppliers in the US but I know a local supplier in the UK that would probably have them on the shelf.
Nick Hull wrote:
Reply to
David Billington
Metric and Multistandard Corp, in Elmsoford NY.
Jim
Reply to
jim rozen
That would come closer to fitting a 20 TPI gauge, not a 22 TPI one. I come up with 1.1545 mm pitch as a direct conversion of 22 TPI. I agree that the 8mm is quite likely, and am now tempted to look in _Machinery's Handbook_ to see whether they document a 1.15 mm pitch.
Nope! And a quick check in the unified threads chart sows 5/16" fasteners at 18, 20, 24, 27, 28, 32, 35, 40, and 48 TPI, but no 5/16-22 listed at all.
If you really need that, perhaps it is time to single-point one on your lathe -- if you have something else to hold it while you mount the chuck.
But what were you measuring to get this 22 TPI figure?
Good Luck, DoN.
Reply to
DoN. Nichols
I was measuring a bolt that fit the internal threads, but I need an allen bolt.
Reply to
Nick Hull
I was measuring a bolt that fit the internal threads, but I need an allen bolt.
Reply to
Nick Hull
O.K. You've now got a pointer to what the thread origin is, thanks to another followup.
Good Luck, DoN.
Reply to
DoN. Nichols

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