Tank Badge Screw Size

pwaltham · Post by **pwaltham** » Fri Mar 26, 2004 1:07 pm

Can anyone tell me the correct size, thread type and head for the tank badge screws for a 1960 AJS model 31DL.

The ones currently fitted are a phillips head, countersunk, but appear to be a metric thread (and loose in the holes).[:0]

Is this correct[?]

I know that the spares scheme sells them but if armed with the correct info I may be able to get some from a stainless fastenings stall at Rufforth, sometime.

Thanks[:)]

Biscuit · Post by **Biscuit** » Fri Mar 26, 2004 2:20 pm

Hi Peter, not sure of the 1960 models, but my '56 has 3 BA oval headed screws, that is C/S screws with a slightly domed head.

MikeM. · Post by **MikeM.** » Sat Mar 27, 2004 6:32 pm

The thread is the same i.e. 3BA, you will probably be able to get them in stainless ( I have bought them at Kempton), but you might find that the heads are slightly bigger than the originals and you may need to countersink the badges a little more.

MikeM.

MikeM. · Post by **MikeM.** » Sat Mar 27, 2004 6:43 pm

ps: The correct name for the type of screw head that Alan described is I beleive is Instrument Maker. Mind you whether those selling said screws at Auto-jumbles call them that is another question.

MikeM.

Biscuit · Post by **Biscuit** » Sun Mar 28, 2004 9:37 pm

Hi Michael, Would'nt disagree with you on the name of the screws, there are as many names for screws and bolts as there are grains of sand in an hour glass. My description comes from 'Machinery's Handbook' which is an American publication. I would suggest however that instrument screws would be chemically or heat treated blue or black or nickel plated. If the badges are of the overlarge, garish and chromed type, would not enlarging the counter sinks compromise the integrity (I like that. have to use it again!!!) of the chrome?.[:I][:I]

Eric · Post by **Eric** » Tue Mar 30, 2004 12:16 am

My book says they are called Countersunk Raised Head or are sometimes called Instrument screws. [:)] That should solve the name problem anyway. The 3 BA size whilst a standard size was very little used, so I would think the chances of finding many around other than from the Spares Scheme is a bit remote. [:D]

pwaltham · Post by **pwaltham** » Tue Mar 30, 2004 11:17 am

Many thanks to everyone for your efforts.
I just might save a lot of legwork and simply order them from the spares scheme.......... they have got to be the right ones.
Thanks again[:)]

MikeM. · Post by **MikeM.** » Tue Mar 30, 2004 10:17 pm

The badges on the 1960 twin I have is of the plastic type so it's easy to countersink them. I have bought said screws from both Spares Scheme (zinc plated) and also Kempton(stainless). The Club ones were the same as the originals in size (and so they should be), where as the heads of the stainless ones were bigger in diameter. Hence the need to increase the countersink slightly.

MikeM.

MikeM. · Post by **MikeM.** » Tue Mar 30, 2004 10:21 pm

The badges on the 1960 twin I have is of the plastic type so it's easy to countersink them. I have bought said screws from both Spares Scheme (zinc plated) and also Kempton(stainless). The Club ones were the same as the originals in size (and so they should be), where as the heads of the stainless ones were bigger in diameter. Hence the need to increase the countersink slightly.

MikeM.