420 440 1045 or 1065 ive bought knifes with these steel grades and i want to know which one is better.
SAE 440 is the best. Classified as high grade cutlery steel. There are various grades of 440: A, B, C, and F. 440 A is the most stain resistant while 440 C has the most carbon and can achieve the highest hardness (Best edge Retention). SAE 440 Chemistry: 16 - 18% Chromium, 0.60 - 1.2% Carbon, 0.75% Molybdenum. SAE 420 is pretty good. Classified as cutlery steel, it is a stain resistant grade but has less chromium and significantly less carbon than SAE 440. SAE 420 Chemistry: 12 - 14% Chromium, 0.15% Carbon (min), 0 Molybdenum Chromium is what makes the steel corrosion resistant. It also adds toughness. Molybdenum adds extra corrosion resistance and adds hardenability. So you can see by chemical components that 440 is highest quality although that also means more cost. 1045 and 1065 are low quality steels and you should probably never use them for a knife. The 1 indicates plain carbon steel with little other alloying elements. The last two digits indicate how much carbon is in the steel. 1045 has 0.45% carbon, mid-range hardenability. 1065 has 0.65% carbon, high hardenability. So if I had to choose I would choose 1065 over 1045 but the difference isn't that noticeable. Everything I said here assumes they have all had the optimum Quench and Temper heat-treatment for their chemistry grade.
