2nd knife, looking for comments on my quality testing results

B

beljohns

Joined
Jan 26, 2011
Messages
9
This is my 2nd knife, 3/16" 1084. I heat treated it using my home built propane forge byfollowing Staceys instructions,.. heating to 1500 then cooling in canola, then to 1300ish cooling in oil, then to 1200 cooling in oil again. Then heat to 1500, quench, temper twice for 2 hours each time. I then just ground off scale and down to an edge and sharpened, didnt worry about trying to finish the blade at this time. I wanted to test it to see how good or bad it was. The picture shows results. I started with it shaving arm hair sharp, whacked the 2x4 300 or so times. At this point in the middle of the blade where most of the hits were, it didn't shave arm hair, but still could at tip and lower part. I then whittled the 2" plus hardwood branch to a point, stabbed the knife tip into the branch very solid 300 times, then whittled on piece of oak flooring. AFter all that, definintely couldn't shave hair anywhere, but it still cut the paper fine as you can see.

I know this is probably a cave man way of testing, but I'm not sure of a really good formal process for me as a newbie knife maker. I don't have a really nice custom knife to compare to, but i know niether my leatherman, any pocket knives, or my current Ka Bar would hold up as well. So, I guess that's a good sign. I'm interested in how other's test their knives, and do you test each one before making it all pretty and putting on a handle? im looking for something to compare to in order to gauge how good or bad this blade may be. Oh, I did perform the brass rod test...bending blade over rod at tip, rolling blade all the way to base watching the deflection and checking that everything returned back to normal with no deflection left. I did it to both sides of blade. I have a couple guys that want me to make them a knife, but Im hesitant with just starting out as i don't want to deliver something that would disappoint. Any suggestions are most appreciated.

Thanks,
Ben
 
Well it didn't chip or roll after all that whacking. The tip stayed in tact And it stayed sharp longer than your other knifes would have. I'd say you have a pretty solid heat treat on that blade. Can you repeat it? I'm curious how you know you were at 1500, 1300, an 1200?
 
Sounds like you have a very decent performing knife. Nothing wrong with that.
 
I'm curious as to why 1300 and 1200? Those are stress reliving numbers, and if that is what you are trying to do, then OK. But if you are trying to "refine grain size", which is 99% of the time what we are doing when descending in heat, then you start with a normalizing temp of 1600F in this case, then drop down. No need to go below 1350F, as there is no grain change below that temp. Only stress relieving.

If you have a way to accurately judge temps, then the 1084 sequence would be 1600F, then drop down to maybe 1500F, then again to 1425F. usually three is enough. If afterwards you want to include stress relief with a propane forge, then you can do 1300F a couple of times, cycling with air cooling. Then ready to harden at 1500F. 130F canola works well with 1084 for sure.
 
I think he was roughly paraphrasing an older post of mine. Currently, for cycling the steel to refine the grain and remove stress, I use - 1600F, quench; 1450F, quench; 1250-1300F, air cool to black. Straighten if needed. Then, I harden at the proper austenitization temp for the steel, which is 1485-1500F for 1084.

Other temps and cycle regimes may be just as good. I am mainly trying to go for a reduced grain size and no internal stress at the time of the final quench.

On a stock removal blade the above is more than adequate. If the blade was heavily forge worked or a laminate, then doing a grain refinement cycle at 1650/1550/1450/1350 would be a good idea.
 
Stacey was correct in his assement, i found an old post i thought i could try to accomplish. i do not have a way to accurately judge temperature, just guessing above and below the magnetic point and trying to remember colors as a gauge. stock removal was from bar stock from Barons so i really am not sure how much stress relief or grain reduction was actually needed. Temper was at 450 in toaster oven using temp gauge bought from walmart. It wont be until i build a few more and run them through the same tests that ill know if i can replicate. Thats part of the reason for this post, to determine an acceptable blade test approach I can use to judge quality. Im interested to hear how others test their blades so I can learn what defines "a good blade". Appreciate any input there.

Im not sure if anyone offers a heat treat service here in Ohio, if so Id like to get with them and understand price. Im also not opposed to building a small heat treat oven if costs to do are reasonsible. Thoughts?

This is a hobby, and I dont mind throwing a few bucks at it to help ensure building a good product and helping the learning curve.

Thanks for replies.
Ben
 
You must log in or register to reply here.
Back
Top