Sleipner

Sleipner is still a fairly unknown name among knife fans: a modern Swedish tool steel that is considered an improved successor to the classic D2. Here are the key facts:

Origin: Sleipner is produced by the long-established Swedish steelmaker Uddeholm, which is now part of the Linz-based voestalpine group. The name comes from Norse mythology: Sleipnir is the eight-legged horse of the god Odin. Sleipner was originally developed as a cold-work tool steel for toolmaking, with the goal of overcoming the weaknesses of classic D2. In knifemaking it became known mainly through the Italian manufacturer LionSteel, which uses it in many of its pocket and outdoor knives.

Composition: Sleipner consists of the following main elements:
Carbon (C): approx. 0.90%
Chromium (Cr): approx. 7.8%
Molybdenum (Mo): approx. 2.5%
Vanadium (V): approx. 0.5%
Silicon (Si): approx. 0.9%
Manganese (Mn): approx. 0.5%

Of interest to collectors: at around 8%, Sleipner contains considerably less chromium than D2 (approx. 12%). This is intentional, because it results in fewer and finer carbides, which makes the blade tougher and easier to sharpen.

Hardness: 60–64 HRC is achievable, with knife blades usually at around 60–62 HRC.

Toughness: noticeably better than D2. Sleipner is less prone to edge chipping, which makes it well suited to sturdy working knives.

Edge Retention: roughly on par with D2, and therefore above classic stainless steels like 440C.

Corrosion Resistance: Sleipner is not stainless. With normal care this isn’t a problem in everyday use, but in humid environments it can’t match stainless steels like 440C, VG-10, or MagnaCut. For this reason, many manufacturers coat their blades.

Practical Takeaway: Sleipner is essentially “D2, only better”: similar edge retention, but tougher and easier to sharpen. Anyone looking for a robust outdoor or everyday knife who wipes the blade down after use gets a very well-balanced steel. Outside of LionSteel, however, it is fairly rare.