Blades breaking

A

Anderson1211

Joined
Feb 16, 2024
Messages
4
New to knife making…. Hey guys I ordered the wrong width of steel .080 and.060 which is pretty thin. 1095 steel. I held the heat in the forge for 10 minutes, quenched immediately in parks 50. I then tempered 2 at 400 degrees. After the HT, I bent the blade a bit and the knife snapped instantly…

My question: is this steel width causing the knife to break so easily? I’ve heat treated thicker steel without this seeming to be an issue. Or am I messing up the HT ? Thanks.
 
Haha. I just went off what the internet said:/
1095, soak for 10 minutes, quench in parks 50 at 130 degrees, temper twice at 400 degrees..
 
You are probably overheating and causing grain growth. Check your steel grain size after breaking the blade. There are pic examples on the forum how your grain should look like, mostly described as very fine sand and almost invisible to the eye. Also if you can only HT in forge, try simpler steels like 1075/1080 which do not have to be held at temperature.
 
Welcome Anderson. Fill out your profile so we know where you are and a bit about you.

That KnifeSteelNerds article will help you solve your issues.

Basic forge HT for 1095:
Heat as evenly as possible on the lowest flame that is stable in your forge. When the blade becomes non-magnetic - Quench it immediately. Temper twice, for one hour each temper, at 400-450°F.

BTW, what type of forge are you using?

Also, whatever you read online is not right. You do not warm Parks #50 to 130°F. It is used at room temperature 60-90°F.

You cannot hold a blade in a forge for 10 minutes at an exact temperature unless the forge has a blown burner with PID control. Even then it is hard to hold an even temperature in the 1500°F range.
 
Thank you. I built the forge out of a propane tank. So I attempted to normalize the steel by heating it up past magnetic, then allowing it to air cool. Then, i let it sit in the forge for 10 minutes, immediately quenched. Tempered twice for 2 hours at 400 degrees. Had a bit of warp so I bent the blade a bit and snap! So I tried another one out of that batch, and snap again…. I’ll try again without warming the oil, and just bringing it to non magnetic and quenching as soon as I hit non magnetic.
 
table salt melts around 1450-1500 .. sprinkle some on your blade the check the temp or buy a temple stick from a welding supply to verify your temp then quench
 
The issue is the ten minutes in a forge with no idea how hot the blade was. It was greatly overheated for the whole 10 minutes. Massive grain growth and brittleness.

With a HT oven normalization and A DET anneal is simple. When working only in a forge you have to find a compromise.
Normalizing of a forged 1095 blade is done around 1650°F. If it is done in a forge, all you can do is guess when the blade is 1650°.

Here is a rough idea of how I do it in a forge:
1) Bring the steel to a good cherry red - about 200° above non-magnetic (a good bit brighter than non-magnetic).
Pull out of the forge to air cool to black.
2) Put back and heat to a little less red than before - about 100° past non-magnetic.
Pull out and air cool to black.
3) Heat until just past non-magnetic and immediately stick in a box/tube of vermiculite overnight. You want a good 3" to 4" of vermiculite surrounding the blade in all directions.
4). Heat as evenly as possible until just past non-magnetic and quench. Keep under the oil for 1 minute. You can check the edge with a file if you want to, but take several strokes, as the decarb may fool you into thinking the blade did not harden.
5) Immediately wash the blade well and place in the kitchen oven or toaster oven at 400-450°F. Hold for 1 hour, cool in running water, and put back for a second hour.
The blade should be hard and properly tempered for the finish grinding and sanding.
 
If you forge outside make sure you heat treat at night. When I first started and heat treated in a forge I sometimes did it during the day. All those blades would always perform poorly because I could not accurately tell what temp I was around.

Soaking in a forge is pretty much impossible, I tried using a stop watch one time and attempted to keep the shade the same for 3min or so…. Felt like an hour, and of course, the HT ended up being pretty terrible. If you can get some 1075, 1084, or maybe some 15n20 give those a shot. It *seemed* like I could get ok results using a forge to HT those steels.

Kevin
 
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