The iron was made from O-1 (oil hardening, Starret brand in this case) steel. I milled some detents at the back so it is easy to hold. An initial 20 degree bevel was milled. This angle is very low (I normally use 30) but this iron is for light cuts on end grain. Heat treatment was by the book: Heat to phase change temp (steel is no longer magnetic, around 1,500F). I use a oxy-acetylene rose bud. Hold at that temp for a bit and quench in oil (I use a gallon can full of motor oil. And yes, it stinks). Bake in the oven to temper the blade (I use 325-350 degrees to get a Rockwell hardness in the low 60s). Then flatten the back and grind the bevel.
- Nipple spear take 2. Got smart and copied the commercial version. Learned a few things about work holding, the bulbous end fits both a collet and a center. On a manual lathe you flip it couple of times. Two tapers.Spoke spear - for digging nipples out of a puddle of linseed oil and putting them in a deep(ish) dish rim socket. Serrations really help retain the nipple. No idea of the angle, just stuck a shim under the front of the spinner and ground away.