Coffin Smoother

Tool steel is a steel hardened by having a high carbon content. One way of doing this is oil hardening.

For this smoother, I decided to make my own blade from soft steel. The process to create a tool steel involved heating the end of the blade to roughly 1400 degrees, then cooling it quickly by submerging it in oil. This cools the steel down fast enough to trap carbon inside the iron molecules, but not so fast that it warps the metal. 

After quenching the blade in oil, the steel is really hard and brittle, and needs to be tempered to a lower hardness on the Rockwell scale (to roughly 62). The tempering process took place in a toaster oven set to 350 for an hour.

Out of the toaster oven, all the blade needed was a honing and a plane.

For the design of this plane, I was inspired by traditional English smoothing planes called coffin planes. I was also drawn to the bridges of metal mitre planes to hold the wedge instead of a cross pin.

I used Burmese Blackwood for the body, and Monterillo for a sole.

Taking a shaving of walnut: