Can anyone enlighten a poor yank about threads in the size of 5/16-26 TPI? This is called out for the piston gland nut on the Stuart Turner model 10V casting set I am currently working on.
I have been trying to locate a tap and die for this size and have looked within the BSW, BSF, and BA series of thread forms to no avail. Of course they are also not to be found in the american system UNC or UNF types here. I have found most every other TPI but 26.
I suppose I can always substitute the UNF 5/16-24 size, but I have been faithful in all other instructions for size of threads and such with this engine.
This is one of two Stuart casting sets I inherited from my Dad, the other being a model 10H. The 10H had been started by him back in about 1970, but is only about 1/3 complete. The 10V was still untouched in its original box. I know they are quite old sets now. The price listed on the included instructions for an unmachined set was 1
- 3/4 Purchase Tax. They cost a lot more now I see. I really do not want to mess these up.
My grand plan is to finish them both as a matched set. So far so good, but I'm not that far into it at all. Mostly focused now on planning, research, and gathering tools, and as I said, I still need to get one more tap & die, 5/16-26. Any hints, or other help at all, would be most welcome at this point. I know my questions must sound like I'm a real newbie, sorry bout that. I suppose most of you guys built your first Stuart Double Ten at age 5, hooked it up to your Mum's tea kettle, and hob-nailed it into a home-built cedar-strip launch for lazy summer cruises on the channel. ;-). Do be gentle.
With kindest regards, Paul Schiller