PDA

View Full Version : How long should my sharp blade last?



DonL
10-31-2011, 09:08 PM
I had the opportunity this weekend to test out a little 2 3/4" knife I made out of Admirals 1075/1080. The knife is 1/8 thick.

I used it to skin, quarter and debone a buck I shot. The buck field dressed around 130lbs, a good one for around here. I had to sharpen the little knife twice (once before I started and once when I was a little past half way done) to get everything done, which included cutting through knee and tail joints and the ball joints of the hips. I normally use a larger 3 1/2" to 4" knife for this job, but wanted to see how long my little knife would hold an edge.

I've never used any other small knife to do this, so I have nothing to compare it to. And later that night, the way my hand and wrist ached I won't be doing it with a little knife any time soon again!

I felt like the knife should have stayed sharper for longer because I have done that job with a larger production knife and it was still sharp when I got done. Just wondering about your thoughts on this. Not sure if I'll keep using the 1075/1080 as I have quite a bit of 0-1 laying around that I'll be using on my next knives. But I like the price of the 1075/1080 and it seems easy enough to work with.

FYI: My heat treat was to bring the blade up to non magnetic in my paint can forge and then let it soak for a minute more. Then a quench in ATF. I tempered it 3 times at 400 for an hour and letting it cool to room temp between cycles.

Knifemaker.ca
10-31-2011, 10:37 PM
There's lots more to edge retention than heat treat. Edge geometry and blade profile go a long way too. Since you asked about HT, I'll toss out a couple of 'maybes' to try.

Antimagnetic isn't quite enough. Try for about 50 degrees above that.
Admiral 1075/1080 can be anything over a large range of carbon and Mn. It's tough to nail heat treat when you don't know what you've got to start with.
ATF should work (stink, but work) but it's really important to get it into the oil fast - especially if your starting temp is a bit low
Lastly, if you aren't using a kiln, get a second thermometer to check your tempering heats. Ovens and toaster ovens are notorious for errors of up to 100 degrees!

The results you are getting don't sound too bad. I've had commercial blades that wouldn't get all the way through field dressing a deer - nevermind boning and cutting up. That would suggest a good start - but searching for better is waht we're all about - right? :)

Lagrange
11-01-2011, 03:42 AM
I've never used Admiral 1075/1080, but I have used production knives to field dress, skin and quarter deer before. Having one needing touched up at that point is not so unusual. I wouldnt feel that your knife was inferior unless it was unusually dull.

Eric

Archer Moon
11-01-2011, 07:02 AM
Might try to temper at a lower temp. With 5160 I temper at 350 for one hour. If the blade comes out too hard you can retemper at 375. Just my two cents.

DonL
11-01-2011, 01:33 PM
Thanks for the replies. I appreciate you taking the time to comment on this.

Knifemaker, I use 2 oven thermometers from different manufacturers in my Toaster oven to monitor the temp. Mine is about 25 degrees off so I have to watch them to get correct temps. I left the blade in the forge for a minute more because I'd read that it needed a little hotter than non-magnetic.

I have a few more blades that I HT at the same time as this one. A few are larger blades, I think I'll go ahead and finish them and see how they perform vs some of my production knives. Well, that is when I kill my next deer or go camping... :)

Frank Hunter
11-02-2011, 03:14 AM
I think your 400 degree tempering cycle is fine, as long as the blade was sufficiently hardened to begin with. When I've quenched in ATF or canola oil I've heated the quenchant to 130-150 degrees to thin it out some. There is a lot of conflicting information from different sources on the final Rockwell hardness attainable with different steels, one of mine is stating that you should be around 59 RHC with your 400 degree temper. If everything went perfectly, that is. I would say your knife performance might have something to do with you having 2/3 or half the blade available with your smaller knife and therefore using it *twice* as much on that deer. Good Luck!

Tod Lowe
11-02-2011, 11:02 AM
I hear ya on using a small knife to bone out a deer.
The right tool for the job makes all the difference. I now use a very large boning knife on my deer and it really does make a difference as far as hand fatigue goes.
http://www.mcmaster.com/#quenching-oil/=erdjn4
This 11 sec oil made a world of difference in my ht when I was using 1080. Im quenching ATS -34 in it now with better results then plate quenching.
That 01 is harder to heat treat then the 1080 from what I have read.
Good luck man!

DonL
11-02-2011, 05:04 PM
@ Frank

I did heat my ATF to 130. Since I was doing several blades, I had to wait to HT between blades when the temp started getting near 150.

@ Tod

I have a whole bunch of "right tools" ;) for this job. But since I had just finished this little blade and it was the first one I had done in 1075/1080, I wanted to see how it would perform. I've now just finished a second knife in this steel and it has a 4 inch blade. Hopefully I'll be giving it a "field trial" soon!! :)

Tod Lowe
11-02-2011, 05:20 PM
Good deal Don. Good luck on your deer hunting and your knife trials.....Post a pic of that knife in action when you get one.:cool:

jkf96a
11-05-2011, 05:28 PM
I have used Kelly Cupples' 1080 alot. I have a kiln, and do 1475 with a short soak and quench in 10 second oil. I have to temper at 450 to keep from chipping, and get RC 60-61. I get two deer easy, and a third if I am careful around the joints. Granted it's really dull by the end of the third deer.

All that makes me think that you're not getting full hardness. Either your austentizing temp isn't high enough, or your oil isn't fast enough. Likely both.

And I'm with you on the short knife. I did my last two deer with a knife that had too short of a handle for the job. Stinks.

clancy
11-05-2011, 10:19 PM
Make sure you get the knife into the quench quickly. You probably have less than 2 seconds to go from forge to quench.