It Doesn't Matter How Many Years I Collect Stuff Just In Case ....

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Geoff_S

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..... I never have the thing I need!

I'll post this here as it is actually a screw from a machine.

Can anyone tell me what type of screw this is and where I can get one from. Yes, just the one so of course I will need a packet of them. Not a problem, I can stick the rest in my "just in case" box 🙂

I've tried Googling and can find plenty of self tappers, but not anything this small and flat ended.

IMG_3621.jpeg


IMG_3620.jpeg
 
Looks like a dome head machine screw to me Geoff, put that in google & it brings up many examples
Thanks Doug, that's worked just fine. I'm guessing M3/M4 so have gone for a small metric kit of them. I'm sure that I will have absolutely
no use for the rest of them 🙄
 
I've save the photo and enlarged it to enable me to better measure the image.

I estimate the OD to be 4.2mm and the pitch to be ~0.8mm. There are few options around that size - the OD is likely to be short of the 'nominal' so it could be an M4.5 which would be 0.75mm pitch but it might be a N° 8 UNC (32tpi) 0.794mm pitch - Nominal OD is 4.166mm = 0.164".

The photo is too poor to determine the thread form but you might be able to test it with a Thread Pitch Gauge. With only 5 crests available I would still expect you to see the difference between (say) 32 tpi and 30 tpi or 0.75mm --- that is assuming that you have access to a Thread Pitch Gauge (or two).

I suspect that it is unlikely to be a standard Metic screw though and I doubt that it is a self-tapper.
 
Where it came from might be a good clue. Bearing in mind its slightly offset to the left in relation to the rule I would guess its M4. And definitely a setscrew, not a self tapper. The length will be measured from the underside of the head, so I would say M4x8, which is a common size. Hard to tell from the images but lòoks to me to have a dual head, ie will take either a flat or phiĺips/pozi driver. If so that pretty much guarantees its metric.
 
..... I never have the thing I need!

I'll post this here as it is actually a screw from a machine.

Can anyone tell me what type of screw this is and where I can get one from. Yes, just the one so of course I will need a packet of them. Not a problem, I can stick the rest in my "just in case" box 🙂

I've tried Googling and can find plenty of self tappers, but not anything this small and flat ended.

View attachment 150713

View attachment 150714
Hello,
I suggest you contact Alton Bolt & Tools, in Alton Hampshire. They have a vast stock and have sorted me out in the past.
Regards
 
..... I never have the thing I need!

I'll post this here as it is actually a screw from a machine.

Can anyone tell me what type of screw this is and where I can get one from. Yes, just the one so of course I will need a packet of them. Not a problem, I can stick the rest in my "just in case" box 🙂

I've tried Googling and can find plenty of self tappers, but not anything this small and flat ended.

View attachment 150713

View attachment 150714
It is most likely UNC thread.
Regards
 
I'm guessing that as its a modern UK machine, it's going to be metric.

It is a bit of a problem regarding UK built stuff these days.
It has an almost equal chance of being either.

ETA ; As has already been said, the thread does look a bit coarse,
for it to be metric.
 
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I think I would lean towards Seascaper ie UNC, as seems a bit coarse for metric. An M4 machine screw would have a 0.7 mm thread pitch coarse (or 0.5mm pitch for fine). To me this would indicate you would expect 10 or 11 threads over the estimated 8mm length, wheras your photo seems to have no more than 5 or 6 threads. If you get stuck you could always drill the hole out to the nearest metric size up and re-tap. Then one of your spares will fit and you will have a "come-in-handy tap!
 
https://www.westfieldfasteners.co.u...MIvs674Za6_AIVhIBQBh2f8wzfEAAYASAAEgLwxfD_BwE
Th
..... I never have the thing I need!

I'll post this here as it is actually a screw from a machine.

Can anyone tell me what type of screw this is and where I can get one from. Yes, just the one so of course I will need a packet of them. Not a problem, I can stick the rest in my "just in case" box 🙂

I've tried Googling and can find plenty of self tappers, but not anything this small and flat ended.

View attachment 150713

View attachment 150714
https://www.westfieldfasteners.co.u...MIvs674Za6_AIVhIBQBh2f8wzfEAAYASAAEgLwxfD_BwE
This place has UNC in the size you need
Regards
 
Like @Geoff_S I've a few "spare... odds and ends" knocking about but never seem to have the right "spare". This thread (no pun intended) has made me decide to get a thread gauge. Seem quite reasonably priced considering the hair pulling to go through to determine size and thread 🤞😉
 
..... I never have the thing I need!

I'll post this here as it is actually a screw from a machine.

Can anyone tell me what type of screw this is and where I can get one from. Yes, just the one so of course I will need a packet of them. Not a problem, I can stick the rest in my "just in case" box 🙂

I've tried Googling and can find plenty of self tappers, but not anything this small and flat ended.
not to put the cat amongst the pigeons, having worked in a business that supplied fasteners, there is a reasonable chance that it was a custom order, so you may have to cut a machine screw down to length. I was surprised at the small numbers needed for this kind if order
 

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