prop zinc screw size

[elk]

I bought a few spare prop zincs from Boatzincs.com but didn't realize the screw didn't come with them.
Is anyone able to measure one of their spare zinc holding screws so I can go to my local hardware store and buy a few. I figure a dab of cured 5200 will work as a thread locker.

Thanks,

[Chips Ahoy!]

The prop zinc is a CAMP P-5 on my boat....Hull 232 2004.
I always have to order this special.
It is held on by a 3/4" castle nut that is made of brass specifically for Catalina.

I just bought a couple of replacements (after 12 years on the first one) from Catalinadirect.
Prop Shaft Castle Nut 3/4" (#K1951):

It fits perfectly.

There is no set screw...never was that I know of.
Using 5200 doesn't sound like a good idea...it will be a bitch to get off.
Underwater...probably impossible.
Just a thought.

-George

[elk]

The screw is a 5/16"-18x1" socket head stainless. A dab of 5200 on the first few threads and let dry, is a good thread locker. No problem getting it off.