Looking for a bolt its not m16 its something else im guessing unc unf bsw or bsf

Pics in hope someone can identify it

Its 15.1 mm about .6 of and inch

And shoulder size is also important as needs to be 3 inch's long before theres thread (the lenth of thread is not that important as it can be cut but aprox inch give or take

Any ideas the thread type is not overly important as long as i can get a locking nut for it

19/32" is 0.5937" or 15.08mm, could it be that?

What does it do?
What's it from?
What's the thread on the end (to understand if it's supposed to be metric or imperial)?
What's the size of the head (as above)?

Is it intentionally S shaped?

Set your calipers to an inch.

Dig the tip into one of the threads. Count the number until the inch is up. (Or use a half inch as applicable)

Then measure the major diameter (od) of the thread.

Look at random thread tables until you find somthing that matches.

That's what I generally attempt to do anyway. Thread gauges can help with the counting if you have one.

When you think you've got it right, see if you can find a known nut to confirm with.

Edit -

Metric (as you may expect!) doesn't work in TPI but rather the metric distance between the threads. So measure ten and see if you can make any sense of it that way also.

The thread looks smaller than the shank, could be 15mm(+rust) shank with a M14x1.5 or a 19/32" shank with a 9/16bsf thread.

Measure the thread OD and between the points of as many complete threads as you can, from the picture that looks like 8 so about 12.5mm/8= 1.56 close to 1.5mm or 16tpi pitch.

The bolt will be a special with the thread/shank step, easy enough to made out of another bolt, knowing the thread dia/pitch required and the finished shank diameter

We need the thread diameter - as above it looks to have been turned below shank dia before threadcutting. I’d guess 9/16”. A thread gauge and knowing the origin usually lead you to the answer.

Looking like the 1/2 whit thread I turned up for Fizzy many moons ago .

thanks for the reply every one sorry im late back to the party work was nuts

this is for work a flail type unit on the back of a tractor that holds the teeth on old unit that you can get replacment teeth for (im assuming as there standard size )

but the bolts are a differant matter no one there knows what bolts they are and a couple have bent broken so we have decided to replace the lot in one go

to try and asnwer a few questions it should not be bent no and yes the shank does seam to be slightly smaller than the shank (smooth part 3 inch bit)

making it would be out the question as we need 20 or more of them (and we have not got lathe for that)

The bolt has nothing on the top just rust

More pics

If counting the thread etc im going to have to get another bolt out as this one is mangled but its the size lenth of shaft im most intrested in as said as long as i can get a lock nuts the thread/ pitch not much of an issue but if working out the pitch thread leads to what bolt it would be worth doing

A random bolt selection I once had, had a few of those sort of oddity bolt, with a smaller diameter thread and a bigger shank. They appeared to be manufactured, not hand made. So maybe someone still has something that would suit. Though finding x20 might be hard.

You say that the top thread isn't important, but, presumably its diameter is? Otherwise, just use any bolt you can find that had the right length and diameter shank.

Or... considering so many are breaking/bending, could you drill the lot out to 16mm and use m16 fine?

A random bolt selection I once had, had a few of those sort of oddity bolt, with a smaller diameter thread and a bigger shank. They appeared to be manufactured, not hand made. So maybe someone still has something that would suit. Though finding x20 might be hard.

You say that the top thread isn't important, but, presumably its diameter is? Otherwise, just use any bolt you can find that had the right length and diameter shank.

Or... considering so many are breaking/bending, could you drill the lot out to 16mm and use m16 fine?

They're called shoulder bolts but nothing about this one appears to be standard. The lack of maker's mark on the heads might mean they're all specials, then you have to consider was the flail manufactured with a non standard bolt, or has it been modified in the past?

@angellonewolf, what's the bore of the teeth? Have you got a good new one on hand?

From your measurements, it's definitely imperial at least.

a flail type unit on the back of a tractor

If they're the bolts that hold the flails on, they'll almost certainly be specials for that purpose (and probably quite strong).

Are they anything like this?

Part# 1496

(Plenty of people selling them.)

I think that is the most niche company I've heard of.
Certainly not the school careers advice list.

There are three standard pitches of metric thread.

If thats from an old Bomford ISTR they were specials, and came with nuts

I think that is the most niche company I've heard of.
Certainly not the school careers advice list.

Maybe thats a good thing these days ?