Bean Cobb lock retaining screw

Hello ¡¡

I recently bought a set of Bean Cobb leg irons.
Most of the plating had gone and one of the shackles would not open with the provided key. The seller had warned me about this condition.

Once I collected the irons I used a good quantity of sewing machine light oil and the lock finally opened.

Then I proceeded to remove the locks for proper cleaning, but in one of them the head of the retaining screw sheared and I will have to drill the remaining shank in order to remove the lock.

I wonder if someone has data about these screws and its threads. It is a commercial screw that may be purchased directly ?

I have tried to determine the thread data but it is not easy even using a thread gauge. It seems to be a 0.5 mm pitch. But being an American product this seems rare.

As I live in Spain, a solution might be to rethread to a bigger size in order to use a metric screw. But I would like to stick to the originals if possible.

I would appretiate your Ideas.

Best regards.

Hi, I haven't been able to work out the thread either but I don't have access to small machine screw info. I am sure that another US collector could help with that, John Bushey is quite a master. I do know that the countersunk head of the screw is larger than normal to modern screws ( proportionate to the thread diameter ) and also the angle is different, more acute.

In the past I acquired half cuffs or broken cuffs, just to get to the screws. I also re-threaded one pair and used modern screws, Didnt look right.

Ian