I've used them on soft metals and wood, they do their job and are fairly straight and as long as you ignore the pressure and let them do their job they won't bend. I'm afraid they won't survive steel, I'd use a higher quality bit for that!
𧱠Bosch 2607017164 Piece Setter Masonry: Advanced Tools for Precision Masonry Work
20 Review
Bit set DeWALT DT7969-QZ, 32 pcs.
39 Review
Tool set Stels Tool set, 1/2", 1/4", CrV, plastic case 94 pcs, Stels, 94 pcs, black
45 Review
Bit and socket set BOSCH Promoline (2.607.017.322), 26 pcs.
24 Review