Some of you may wonder why Ridgeline offers two different steels as blade material, so I thought I’d make a quick writeup up of what can be expected from each. D2 D2 is technically an industrial tool steel used mainly in high production dies and industrial cutting, and has found wide use in knifemaking due to its particular properties. When heat treated to ~60 HRC hardness, D2 balances impact toughness and edge retention well, making it a proven material for edged applicatio