A bench plane is made-up of three cast iron parts. The block plane has two to four cast iron parts. Each of these parts have a casting number assigned to it. Millers Falls was not consistent to emboss the casting number on the different plane parts. A couple of examples would be that the No. 8 lever cap almost never has a casting number, but the #9 lever cap has had a casting number from day 1.

In the early years, especially on the body of both bench and block planes, the casting number was not embossed on the bed. What you would see is a single number on the bed. We know at the foundry they used a template to form the cavity in the molds. Was this single number the template identifying number? Moving into the 40’s, the bodies start to show the casting numbers and by 1949 onward the casting number is standard on most of the bodies.

In the table below, there are eight sections for the different cast iron parts. Each section is ordered by the casting number. If a part is found with a casting number, it is listed under the “Validate Part” column. Cast iron parts that have never been found with a casting number will be listed under the “Unknown Part” column.