heat treating problem

[gasloffer]

I made my first knife a little while back and while it looks decent the thing is impossible to get a edge on. I did stock removal on some 440c and built a fire in an old grill. With the aid of an old blow dryer i got it up to nonmagnetic in about 30 minutes then doused it in motor oil. To soften it back up i put it in the oven at 500 for an hour and it turned golden so i figured it was good. I finnished the knife but its too hard. A file will bounce off unless moderate pressure is applied. Will taking this edge to the grinding wheel ruin it? I am open to suggestions for next time and any hints on how to make this knife sharp.

[cedar_fluteman]

If you have finished the knife and only need to put an edge on the knife just don't get the blade so hot it turns blue when you sharpen it however you sharpen it. Not sure if the way you heat treated the 440-c is right or not? I'm sure somebody will tell you what you need to do in the future to heat treat 440-c.

[AcridSaint]

I think that cedar_fluteman is right, you need to ht stainless differently. I've only worked carbon steels, but iirc you need to soak the steel and a specific temp and then use quench plates, not oil. I think 440 is more forgiving than cpm steels, but none the less I'm pretty sure that the bbq forge isn't exact enough to get consistent results.

[gasloffer]

I guess i'll just have to try some carbon steel next time around. I am just frustrated that a made a decent looking knife that isn't functional. I'll use stabilized woods this time too. The scales expanded in the moisture a bit but have shrunk back down. After reading what not to do I guess that I have plenty of rookie mistakes to make. C'est la vie. Thanks for the replies.

[AwP]

I'd reccomend 5160 or O1, those are two of the easiest steels to home HT with an oil quench. If you make big knives I'd go with the 5160, if you make smaller ones then the O1.

[Omega]

two quick points of advice,

1) either get a pro to ht ss or go out and buy a ht oven.

2) with most things but especially heat treating never just "figure it was good"




bill

[Nooksak]

another thing to do is to do 2 "bakes" in the oven i usaly cook them at about 450-75 for an hour let cool , and then do it again to help relaive some of the intrenal stresses....justa htought(sorry fo trthe typos i work night shift and its a bit late for me )

[gasloffer]

One strange thing I noticed was the blade became a little bit magnetic after the heat treatment. I only noticed when sharpening the blade the shavings tend to stick. Is this indicative of anything?

[Ropes4u]

http://www.toolanddie.com has free shipping on koncor steels and the price is right..