Steel.................... Rc Edge Retention Breaking Strength Stain Resistance   ATS-34.............@ 61 5 8 6   BG-42...............@ 62 6 7 8   440C................@ 59 4 9 8   S60V................@ 57 9 5 6   S30V................@ 61 10 8 10

ATS-34 always a good choice, has been the hottest high-end stainless in the 1990s. 154CM is the original American version, but for a long time was not manufactured in the sizes knifemakers need, and then not at all, so knifemakers switched over to ATS-34. CPM is again making high-quality 154CM, and some companies seeking to stick with American-made products are using it. ATS-34 is a Hitachi product that is very, very similar to 154CM. Normally hardened to around 59-61 Rc, it holds an edge very well and is tough enough even at that high hardness. Many custom makers and production companies use ATS-34.

BG-42 is somewhat similar to ATS-34, with some major differences: It has more manganese and molybdenum than ATS-34, and has 1.2% vanadium (ATS-34 has no vanadium), so look for better edge-holding than ATS-34. BG-42 is usually hardened to 61-63 Rc.

440C is an excellent, high-end stainless steel, usually hardened to around 56-59 Rc, very tough and with good edge-holding at that hardness. 440C is generally considered a very good general-use stainless, tougher and more stain resistant than ATS-34 but with less edge-holding. I keep the hardness down to a maximum of 59 Rockwell C scale. Any harder than that I have experienced a fine gray line of edge chips when attempting to put the final edge on it. It makes excellent fillet knives at 56 Rc that will take 90 degee bends on 10" blades. Also makes very good kitchen cutlery at 56 Rc.

S60V is a steel that holds an edge superbly. This steel is made with Crucible's particle metallurgy process, and that process allows it to be packed with more alloying elements than traditional steel manufacturing methods would allow. It's very high vanadium forms some vanadium carbides during the tempering process which accounts for the great edge holding. Depending on heat treatment, expect to have to work a bit harder to sharpen this steel. Don't expect ATS-34 type toughness. Due to the vanadium carbides that develop during heat treating, edge holding isn't dependent upon steel hardness alone, so it is typically hardened to just 57 Rc which helps hold down brittleness.   S30V is the only steel on the market that has been designed for knifemaking. It's alloys have been chemically blended to bring out the best qualities of edge holding, toughness and stain resistance. Manufactured by Crucible it too like S60V is made from powdered alloys heated in a cannister to bonding temperature. The resulting billet is then roll forged by conventional mills into sheets and bars. Edge holding is incredible and it just a little bit better than S60V since it can be tempered harder and still not be overly brittle. I personally find S30V easier to sharpen than BG-42 and S60V.

PERCENTAGE OF ALLOYS IN STEEL STEEL C Mn Si S P Cr Mo V N ATS-34 1.04 .41 .25 .03 .02 13.75 3.55 -- -- BG-42 1.15 .50 .30 -- -- 14.5 4.0 1.2 -- 440C 1.10 .45 .30 .03 .04 17.0 .50 -- -- S60V 2.20 .50 .40 -- -- 17.0 1.0 5.50 -- S30V 1.45 .40 .40 -- -- 14.0 2.0 4.0 --

ALLOYING ELEMENTS IN STEELS CARBON (C) increases edge retention, raises tensile strength, increases hardness and improves resistance to wear and abrasion. CHROMIUM (Cr) increases hardness, tensile strength and toughness. Provides resistance to wear and corrosion. COBALT (Co) increases strength and hardness and permits quenching in higher temperatures. MANGANESE (Mn) increases hardenability, wear resistance and tensil strength. MOLYBDENUM (Mo) increases strength, hardness, hardenability and toughness. NICKEL (Ni) adds strength, hardness and corrosion resistance. PHOSPHORUS (P) improves strength, machinability and hardeness. Creates brittleness in high quanitities. SILICON (Si) increases yield strength, tensile strength and de-oxidizes and de-gasifies to remove oxygen from molten metal. SULFUR (S) improves machinability when used in minute quantities. TUNGSTEN (W) adds strength, toughness and hardness. VANADIUM (V) increases strength, hadness and resistance to shock impact.