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Drum retaining screws - Printable Version

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Drum retaining screws - Viteran - 03-11-2018

The drum retaining screws I have are not long enough to screw into the hub of my Ruby,they are 1/2” and I need
9/16”.
I intended to look for some at the NEC but when offering the screws up ( without the hub) they do not grip cleanly. The question is what thread and size should they be as I do not want to force in a screw of the wrong thread.they appear to be  a BA “0” thread.
If this thread is correct then I can use a tap to clean them up
Replies would be appreciated.
Ian


RE: Drum retaining screws - Graham Honnor - 03-11-2018

Ian

It should be a 1/4" BSF.

Graham


RE: Drum retaining screws - Viteran - 03-11-2018

Thanks for that. I actually offered up a 1/4 “ BSF  bolt to see if the thread would fit but it started to jam so I backed off.
I should be able to get some BSF screws at the NEC and will clean the threads up with a tap now I know what I should be doing.
Ian


RE: Drum retaining screws - Nick Turley - 04-11-2018

Our trusted A7 supplier's have these.


RE: Drum retaining screws - Tony Betts - 04-11-2018

Many people will not realise that originally there were TWO different lengths of these screws.

As the girling cast iron drums are thicker, austin fitted longer screws.

Be careful when buying you get the correct length.

I find it a good idea to trial fit the hub to the drum off the car, then you can see if threads are two long. And can grind off the excess.

Tony.


RE: Drum retaining screws - Parazine - 08-11-2018

Early drums were not retained with screws (prior to some time in 1927 I think). So if you come across 1" drums without screwholes or hubs with countersunk screwholes, they belong to the early cars. I guess they take a different length screw again.
I presume 6" drums were similar but have not had the chance to play with them.....