stupid question time re BSW bolts

[scammell man]

where do people buy their BSW bolts, especially large and unusual sizes? It appears most people are passing of UNC as BSW as they fit, well at least they do up. However they will not give the proper strength and are not always a substitute for a proper BSW bolt / machine bolt.

[81119]

Try G F M advertise in Old Glory helpfull chap Tel 01302 556406 ask for George , he will awnser upto 9pm as he deals with many in the heritage world, supplies many types of hardware.

Or write to :

G F M
Bristol House
11 Roman Road
Bennetthorpe
Doncaster
DN4 5HA

[scammell man]

yep top bloke

I think my requirement stretched him, but he has come back with an acceptable solution.

I think George took it as a personal challendge!

thank you

[81119]

Glad to be able to help !

Yep top bloke, nearly time to talk to him about another order !!

[buzzy bee]

UNC has one thread in 6 different to BSW or the other way around doesn't it?

[weidner]

Originally Posted by buzzy bee

UNC has one thread in 6 different to BSW or the other way around doesn't it?

The pitches are the same in the smaller sizes , except for the Joker . 1/2" BSW is 12 tpi , 1/2" UNC is 13 tpi . Tell this to the blind idiot who ruined every nut and bolt in a whole drawerful which we used for clamping jobs onto our milling machines .

BSW thread angle is 55 degrees , UNC is 60 degrees .

[Burrell2551]

Make them ! Its the only way if you want to get the old hex sizes right.
Mcreadys still have the old hex sizes of steel bar in stock in quite a few specs.

The OLD sizes are as follows

W Size Bar AF size
3/8" 0.710"
7/16" 0.820"
1/2" 0.920"
9/16" 1.010"
5/8" 1.100"
3/4" 1.300"
7/8" 1.480"
1.00" 1.670"

If you have a lathe this is an easy, but slightly boring job ! I tap under power and have use of a die box for the bolts and studs. Also, buy a tipped part off tool (the blade in block type). You will rip through hex bar in seconds when parting off.

[steamy1]

Easy to make as you describe, but what if he needs high tensile, not so easy.

[Burrell2551]

Originally Posted by steamy1

Easy to make as you describe, but what if he needs high tensile, not so easy.

I agree in part..some grades you cant obtain that easily.

I tend to buy EN8 (but note - boiler studs should be en3b/32)

Tensile strength of En8 = minimum of 500N/mm2 (around 35 TSI) - OK this is not as much as an 8.8 bolt but I would have thought this was more than enough for most applications we would be dealing with in this hobby for fixings... and certainly I would guess better than anything the original makers used. (maybe outside carrot bolts for cylinder in some cases carl ?)