Pittsburgh rolls come on all of these models with a (no charge) choice of opposing rolls. Choices include:
1. Drive Cleat (most popular) Drive cleats are used to hold two pieces of rectangular duct together. Looks like this:
2. Acme Rolls. Acme is used to marry two pieces of sheet metal at the edges. Once two acmes are joined, they are smashed to fix them. Looks like this:
3. Right Angle Flange Rolls. Make the “male”, 3/16” flange for the Pittsburgh look. Not recommended in that a flanging attachment or straight brake is a better and more cost effective way of making the flange.