Peter Tovey

I think 3/8 UNC should fit microphone, I think it's 3/8 UNC for the small one and 5/8 UNF for the large one. UNC being coarse 3/8-16 and 3/8 UNF 3/8-24 teeth per Inch.

3/8 UNC and Whitworth are both 16TPI but I don't think that's true of all diameters.

 

 

The mic threads should be BSW if 3/8", although there are an increasing number being made as UNC. Think it derives from camera tripod mounts which are either 1/4" or 3/8" Whitworth. For the short length of thread engagement and low torque in this application they're essentially interchangeable. The thread angles are 5 degrees different (55° BSW and 60° UNC). Thread pitch is the same for all common sizes except 1/2".

The drill size for a 3/8" BSW helicoil is conveniently 9.9mm. So you could drill out half the length of an M10 studding connector nut, helicoil insert to 3/8", and screw in a stub of 3/8" stud with a dollop of threadlocker. Job done.

Locker and Riley are the boyo's. They also did some foyer work at the Palladium.

 

Hayles and Howe are the other likely candidates for the repair work, I should think. Have done a lot of theatre work, including some repairs for me.