Let's be clear. These are NOT pie cuts! Pie cuts are made using straight tubing. A series of pie cuts welded together are geometric in shape, not exactly smooth flowing.
These tight bends are NOT mandrel bends, either! What are they? A special process that uses special tooling to get a perfectly round 3 inch OD.
What you're buying is THREE of these bends, each 30 degrees, to total a 90 degree bend. These can be clocked for a quick jog over so larger mandrel bends are not wasted, and less cutting! These are smoother flowing than pie cuts, and utilize less welds to maximize efficiency while building an exhaust system.
They are made from 304 stainless.