These are well made and fairly close to their nominal size making them easy to use. They are stainless steel but I don't know the exact alloy. They are very, very weakly magnetized and almost completely unresponsive to strong magnets. The steel is quite hard and doesn't scratch or scratch.
POWERTEC 4 Inch 20 2 Inch QTB1005 T Slot: A Revolutionary, High-Quality Power Tool Accessory!
8 Review
π Carriage Prime Line Products GD52103
6 Review
π© M6 1.0 Stainless Steel Flanged Hexagon Flange
8 Review
π© 5-Pack of M8x60mm Stainless Steel External Hex Expansion Bolts by Yasorn
10 Review