'M' sizes. Help...

[allen]

When I want a bolt, I rummage through my box of bits, and find one that fits. Usually works.

But this time, I want 2 x wing bolts (or wing screws), which I haven't got, so I've got to buy them - but I haven't got much of a clue as to whether they're M6s, M8s, or M anythings.

Is there an easy way of finding out (without crossing the threads), or, hopefully, can you buy a pack of assorted wing screws?

Ta.

Allen.

[The Builder]

Difficult to say without measuring the thread pitch, Allen.
For metric bolts (M6, M8 etc) the number refers to the actual diameter of the bolt thread. A 6mm diameter will take an M6 wingnut.

Try one, it'll either go on easily or it'll stop after about a turn or so.

[Old_Geezer]

What you could do is invest in a set of small pots/boxes/whatever and spend a day checking against known threads so they are sorted for next time. I know I bought such things once, and one day I'm actually going to use them. I'm sure of it.

Of course the downside is that you do actually need to identify and maybe even buy, your reference threads.

[allen]

Thanks Builder, Geezer. I've even got an old micrometer somewhere, so I can measure the bolt in question, which should help.

Putting everything in boxes? Yes, I know. I've even got a supply of old Golden Virginia 2oz tins for the job. But my shed is a place of lost dreams, of unstarted projects, of timber and tools I'll never use; I should clear out the lot, but you know how it is. You look at something, and think 'well, maybe I'll get round to that in the summer/autumn/winter/etc.' I don't hoard things in the house, quite the opposite, but in the shed? Can't throw away a rusty bolt - just in case.


Allen.

[MichaelZZ]

Haven't you got a friendly neighbourhood DIY shop in your area? If I wanted the sort of thing you're after I would just pop in there and either show them my nut, bolt, etc and ask if they've got one that will fit. More often than not they'll be able to identify the size / thread but when they can't they'll say, "Have a rummage around, luv. See if you can find owt that fits!"
Which reminds me of the tabloid newspaper headline reporting the escape of an imate from a lunatic asylum who then went on to rape a laundry attendant; "Nut bolt, screws washer"

[allen]

Michael:

Homebase, Wickes, one or two similar ones whose names I've forgotten.

And no, they don't let you rummage through their box of bits.

Now, Frances Stores would have done so - but he closed down in 1980. If you've still got a neighbourhood hardware shop, nail him down!

A.

[allen]

Well, obviously my new knowledge of M sizes isn't adequate!

I bought some M4s, then some M5s. The M4s were small - just fell into the hole. The M5s were too big - I could maybe force them in, but on the micrometer they're a fair bit bigger than my original 'X' size. (I bought ordinary hex-bolts for this experiment rather than wing bolts, which are so expensive).

They're for a bike mirror, which is made in the US. Well, I suppose it might be made in China, but the 'BlackburnDesign.Com' website is American, and they don't say where they get their gear made.

So do the yanks use some sort of half-sized M bolts? As it seems what I want is an M4.5!

Any ideas, or shall I try and find another way round the small but annoying problem?

Thanks for the interest.


Allen.