Vintage KD Convertible HackSaw - Shortening a Saw Blade

In this video I make a short 3" blade for this vintage K-D Tools Convertible Model 99 Hacksaw.
This saw was designed to use blades from 3 to 12 inches. The shorter blades allow it to cut around obstructions.
Since the saw blade is made from hardened steel, we'll spot anneal it to avoid damaging the heat treatment on the cutting edge.

1920 Patent:
https://patents.google.com/patent/US1382448A

1946 Patent:
https://patents.google.com/patent/US2531135

1934 KD Catalog:
https://archive.org/details/k-d-tools-catalog-no-16-1934/page/6/mode/2up

1948 KD Catalog:
https://archive.org/details/k-d-tools-cat-no-24-1948/page/14/mode/2up

1969 KD Catalog:
https://archive.org/details/k-d-tools-catalog-69/K-D%20Tools%20Catalog%2069/

00:00 Intro
00:50 Making a Short Blade
02:35 Cutting Demo
03:11 Saw History
03:44 Other Design Features
04:25 Outro