Steel Choices
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 applications. With a Charpy C-notch impact toughness of 21 ft-lbs it comes close to 10x as tough as the popular 440C stainless (2.5 ft-lbs), and also exhibits 120% higher edge retention than 440C in CATRA edge retention testing. When it came to developing hunting knives with optimum performance, there was no questions at Ridgeline what steel the foundation would be built on. It had to be D2.
It is important to note that D2 is a carbon steel, meaning that it is non-stainless, and can rust. If you choose to buy a D2 knife anywhere, you should plan on keeping the blade oiled and dry it quickly after washing.
S35VN
There’s a lot of us out there that don’t want to have to worry about keeping a knife that lives in rough conditions (and may sometimes be forgotten in a pack after a wet hunt) oiled and dry. For that reason, we realized that offering a stainless knife is important to our customers. Crucible Industries S30V has long been a favorite knife steel around here, but it was found to be prone to chipping of the cutting edge in use. After an admittedly brief research session, Crucible Industries S35VN stood out as a material that fit with Ridgeline knives, as S35VN was developed by Crucible as the answer to the S30V toughness issue. Crucible Industries was able to replace a small amount of the vanadium carbides with niobium carbides to increase the impact toughness without sacrificing edge retention. Since both S30V and S35VN rely increased content of vanadium carbides (and niobium carbides in the case of S35VN) than chromium carbide like 440C, their edge retention is 145% greater than the popular material! Through this small change, the Charpy C notch toughness was raised from 10 ft-lbs to 12 ft-lbs, nearly 5 times as tough as 440C’s 2.5 ft-lbs.
In comparing D2 and S35VN, you will see that the S35VN offers higher edge retention at the cost of impact toughness. S35VN also offers the advantage of a stainless steel, worry free blade, though the cost is slightly higher due to material and processing cost differences. It truly comes down to your preference.
Now for something that most knife companies won’t tell you: There is no magic blade steel. There are hundreds of steels out there, and even more opinions. It doesn’t take much looking around to find sources touting the “absolute best blade material”, and there are undoubtedly many that are VERY good. It is also possible to make a knife from the best material available, yet end up with a sub-par blade. As the old heat treaters saying says “there are no shortcuts in heat treating”. At Ridgeline we are committed to using digitally controlled heat treat processes to ensure consistent, high quality blades made from materials that we feel are optimum for the application. We are also committed to using materials from the Crucible Industries, the US based tool steel manufacturer that holds a reported 70% of tool steel patents. When we say “100% US made”, we mean it.
