Joined: Dec 2017 Posts: 100 Threads: 16
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Location: South yorkshire
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
Joined: Aug 2017 Posts: 90 Threads: 17
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Location: Hereford
Ian
It should be a 1/4" BSF.
Graham
Joined: Dec 2017 Posts: 100 Threads: 16
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Location: South yorkshire
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
Joined: Aug 2017 Posts: 504 Threads: 13
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Our trusted A7 supplier's have these.
Joined: Aug 2017 Posts: 1,808 Threads: 99
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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.
Joined: Aug 2017 Posts: 888 Threads: 48
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Location: North Wiltshire
Car type: 1927 Chummy, 1938 Big Seven 1/2 a Trials Chummy
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.....
