Identify a thread

[rick]

On my McCulloch chainsaw, the outer casings are held in by screws .... which go into U Spreader Nuts (though I would describe better as push-on 'C Clips' captive nuts) They look like:

The screws appear to be self-tapper thread for rather than machine screws ..... I measured one and it is 5.17 diameter 14 tpi, which matches pretty well with a No 12 Self Tapper ..

does 5.17 - 14tpi seem right for a No 12 ?

Second Q is where can I buy self-tapper U clip / C-Clip nuts

McCulloch want £6.8 for a single clip !

[The Nomad]

Ah! Tinnerman's aka 'sheet nuts' aka 'speed nuts'.

Ebay?

Avpx

[Graham.]

I've always called them Spire nuts.

[Rob Morley]

I typed no.12 nut into eBay search and came up with this:

'm sure there are many others, but £2.25 for 10 delivered seems a reasonable small-quantity price.

[newshound]

Although a fiver for 100 from RS is even better value. You could even bag up the surplus in fives or tens and put them on eBay!

The "tpi" is not usually critical for self tappers, the main thing is that you want the "core" diameter to be similar to that of the "hole". I never deliberately throw self-tappers away for this reason, they all go into a big jar.

[Rob Morley]

Here too, although they'll be in a variety of jars and tins scattered around the place - most of my "that might be useful one day" stuff is.

[FMurtz]

[Brian Gaff]

Blimey, I through a box load of these things away a couple of years ago, they were black and used to be used to hold the back covers on old crt TV sets and of course every time you took the back of you lost a nut as the clamping action that was supposed to retain it on the metal part within nearly always either broke or slipped off. Brian

[rick]

I was searching for c-clip or U-nut and they were 5mm, 6mmm etc. should have searched for No12

Just ordered pack of 5