What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Die size to thread SSP-120?

Amazon-1

Active Member
I am working on the engine baffles. The plans call for cutting threads into the ends of SSP-120 stainless steel pins.

I don't own a tap and die set and to date have not needed one anywhere on the build. I would prefer not to have to spend 50 to 100 dollars on a tap and die set for this one small task and am hoping to just buy the one die I will need for this.

Does anyone know the size die needed? I mic'd the pins at .117".

Thanks,

Bruce
 
Major dia

Major dia for 6-32 is 0.138"
Major dia for 5-40 is 0.125"
Major dia for 4-40 is 0.112"

If your major dia is 0.117", probably a #5-40. A 4-40 would be to tight and probably break the rod.

Having an undersized (0.117") for a #5-40 would reduce the thread strength enough to concern me.

Just my $0.02
 
Last edited:
I just did this last night. It is definitely 6-32. It was somewhat difficult to cut the threads in the stainless pin but with some lube and elbow grease it was completed. Putting the baffles on the engine this afternoon.
 
Thanks for the clarification. Hopefully the blanks are bigger that the 0.117" dia mentioned earlier.

actually you shouldn't hope that. Plenty of thread engagement wih 6-32 at that OD, for this application. Even at that diameter, it is very difficult to hold that rod while you make threads, without a lathe chuck. It would be REALLY VERY difficult if that rod were at the major OD for 6-32.
 
Last edited:
I found the metal lock nuts to be less secure on these threaded rods than I would like. I ended up using jam nuts with the metal lock nuts.

Could just be my particular die set but an easy fix.
 
Threading baffle rod

Just threaded mine yesterday.6-32 die worked good bevel rod ends before starting die. Use lube and 1 turn then back up to clean chips.336537E8-29B6-487B-BC83-B7276CA9B7CC.jpeg
 
I am working on the engine baffles. The plans call for cutting threads into the ends of SSP-120 stainless steel pins.

I don't own a tap and die set and to date have not needed one anywhere on the build. I would prefer not to have to spend 50 to 100 dollars on a tap and die set for this one small task and am hoping to just buy the one die I will need for this.

Does anyone know the size die needed? I mic'd the pins at .117".

Thanks,

Bruce

For future reference, another option I used was to buy stainless threaded rod from Mc Master-Carr. It has worked great. Just cut to length and bend it.
 
For future reference, another option I used was to buy stainless threaded rod from Mc Master-Carr. It has worked great. Just cut to length and bend it.

Just make sure it stays far away from other parts and the engine.
Stainless threaded rod with the addition of vibration would just about be the equivalent of a hack saw blade.
 
Back
Top