The day before yesterday I went to my newly discovered machinery suppliers to get a 300mm brass rod, a HSS 1/4” tool blank, a 5/32x40tpi ME, no. 1 tap and die and a 3/16” taper reamer all for making the drain cocks. The guy said he’d have to order in the tap, die and reamer. Great I said. Next morning I get a phone call saying they’re in. Wow they must have a beam me up Scotty machine. Went in, he handed them over and said $388! I nearly fainted. How much I yelped. He did a check on the paperwork and said sorry $308! I suppose it’s my own fault for not asking for a quote but seriously? I said sorry but there’s no way I can afford that. He asked me if I was a member of the Canberra model engineering club. I said my membership is pending. He said in that case I can do them for $208 I said I was sorry for any trouble caused but I couldn’t take them. Really embarrassed. I only paid $57 for a full set of BA taps and dies!
So, I decided to use 4BA instead and I’ll try and make my own reamer. The American guy’s compound build that I’m copying shows them but doesn’t say how he makes them but I’m guessing he machines the taper onto a mild steel rod then grinds it just over half way across at an angle then hardens it. ??? Any advice would be appreciated.
I used his microscope photos based on the size of his 5/32 ME thread to gauge the dimensions of a cock and made a pattern which I will repeat if I’ve got it near enough right.
This is my take. It’s overall protrusion from the cladding is 0.530”. Diameter of globe (rugby ball actually) is 0.260”. Is this anywhere nearly right??




It took me 3 hours to grind that 1/4” HSS blank down to that size and shape. My quenching water pot actually got hot and my fingers are really sore. I’ve got a really big bench grinder with a course and fine 9” wheels.
Jerry C.