SP 109/156 BA Socket Head Screws

[mcgowman]

Anybody know if it still possible to obtain the socket/allen headed screws used on the diaphragm cover clams?

I located the ScubaPro part #: 01-101-128

Appears it was used on the SP 109/156 regs, as well as other purposes on the G200 and G250.

I have a 109 that came to me with phillips headed screws which are starting to get a bit difficult to work with. A socket/allen head replacement would be much better.

3rd party source would be fine, but don't know the specs to order correctly. Just preferring it be stainless steel.

Thanks in advance.

 

[The Ruttmeister]

Looks like a #4 x 1/2".

Take the parts to your local hardware store (assuming they have those big banks of drawers full of every screw) and check the fit. They usually have stainless.

I'm curious to see if the head fits.

 

[Angelo Farina]

Be aware that some 109s use metric screws (M3), some use American threads...
If you go to a serious mechanical part supplier they can measure the thread and order the replacement screws.

 

[happy-diver]

I have ground the diameter of screwdrivers to fit down into the clamp as I also have the heads of screws

 

[Luis H]

Like @Angelo Farina mention, some had metric screws and some had US standard screw (#4-40)

The #4-40 has a major diameter of 0.112 inches and 40 treads per inch is a pitch of 0.025 inches per thread.

The M3 has a major diameter of 0.1181 inches and a pitch of 0.5 mm (0.0197 inches).

So be careful not to confuse them.


They also came with three types of head: flat blade screw-driver, Phillips, and hex key (Allen wrench). My preference is the flat blade. I am not a fan of special tools, specially tiny hex keys.

You can get this ones if the are the US standard:

About Us

You can also get them from McMaster Carr.

 

[mcgowman]

Excellent info. Thank you all.