case hardening steel is adviced or thru hardening steel is most suitable?
I don't know your application, but here is some advice. Case hard provides a hard shell around soft steel, depending on the bake, the case is usually .002-.008 thick. (thousands of an inch) Heat treated steel or tool steel is hard all the way thru. Case hardening, provides toughness with flexibility, however, once it's compromised, the part is scrap. Hardend tool steel is extreemly hard throughout and the harder it is, the more brittle it becomes. The application of the part will help you to determine the material needed. For instance; Plastic injection molds are very hard so the hot plastic wont erode them over years of use. Punch Press dies aren't as hard but are tougher to withstand the shock. Machine bolts are case hardened so they can last, but soft enough to allow some stretching during tightening. Either way, the time in mfg will be about the same. Most tool steels today cut like cheese, but take time to be heat treated. Tool steel will cost a bit more than low carbon steel. Low carbon steel is as machinable, and cheaper, but, again, the baking period is as long or longer than tool steel. There are a lot of materials on the market today that maintain the durability of heatreated steel without having to go thru that process. 4140, ( or chrome/moly) comes to mind. There are also some 400 series stainless that work as well, and others. You need to determine strength, flexibility, ease of mfg, cost and repairability when considering which steel to use.
Sep 27, 2017