The shrinker stretcher is one of the more underestimated metal-forming tools in the shop. This excellent video by Lazze demonstrates a few important secrets of these powerful and flexible machines.

We’ve featured metalworking guru Lars Jansson, better known as Lazze, before here at Mac’s Motor City Garage; namely, in his enlightening tutorial on the basics of the English wheel, one of our more popular shop features. Here’s another equally excellent primer, this one on the basics of the shrinker stretcher.

In a nutshell, these simple and relatively inexpensive tools (available from numerous suppliers, including Lazze himself) are designed to form inside or outside curves of almost any radius in flat metal sheet—which makes them far more powerful and useful than folks might imagine. And as usual, there are a few important secrets to operating the shrinker stretcher that might not be immediately obvious to the casual user. Even if you never use a shrinker stretcher yourself, this clip will give you a greater appreciation for the metal-forming arts. Video below.