Heat treating 01 steel using kiln

I am new to this forum and to knifemaking in general. I have made two knives so far out of 01 steel. they both have five inch blades and dymondwood handles.I used a kiln in the machine shop where I work.I was wondering If prolonged time in the kiln is going to cause significant grain growth. should I preheat the steel to about 800 and then bring up the temp. to 1500., or should I heat the kiln to 1500 and put the knife in. I was also wondering about the time it takes to get the blade from the kiln to the quench. how quick do I need to be.The knives I did previously did not seem hard when checked with a file but tested at rockwell 57c.I tempered in my oven at home at 350 deg. for two hours. Any help would be greatly appreciated. Also , do I need to put a coating on the dymondwood or just buff. thanks

[This message has been edited by Chuck K (edited 02-23-2000).]
 
primos

primos

Joined
Jan 27, 2000
Messages
615
Chuck,
Something must be amiss. A temper at 350 F. should not have rendered 57HRc. If the O1 was fully hardened at the quench, it would have been about 64 - 65HRc, and tempering at 350F. would render about 61HRc. Here's a textbook example to try for O1, and you can play around it as you make more.

Place the blade in the kiln and bring it to 1200 degrees F. You can hold it for 10 minutes or so. There won't be any grain growth at this temp. This is a preheat. I've tried it both with and without this step and had good results.

The critical range on O1 is 1450 - 1500 F. I split the difference heat to 1475 F. Once critical is reached, get the blade into the quench as soon as possible. The rate at which the steel cools is very important. Don't stand around chit-chatting on the way from the kiln to the quench.

After the steel is cool enough to hold by hand, run a file across the blade down by the edge, and it should just skate off the steel.

Temper 2 times in the kitchen oven at 400 -450 degrees F. NOTE: Kitchen ovens are not precisely calibrated. Some run hotter than the setting, and some run cooler. This is where you have to play around to find the right setting for your particular oven. Same thing goes for toaster ovens. If your oven was exactly right, AND the O1 was fully hardened at the quench, you could expect to get around 59HRc with a 400 F. temper, and 58HRc with a 450 degree temper.
 
hello,

I have found in almost 13 yrs of doing this that a KILN for heat treating blade is BAD, BAD, BAD!! There is a Two fold reason for this.

1. Even if the Blade is at Critical temp in
the kiln, when you open the Door to
to take out the blade, you instantly lose
Heat and the blade that was at critical temp by the time it reaches the quench medium is not a Critical temp Thus,doesnt Harden Properly. I am talking Oil Quenched
blades here,not Air Quenched.

2. Increasing the Temp of the Kiln to make up for the heat loss incured from taking said blade from the kiln to Quench can also Cause Excessive Grain Growth and is a BAD thing!

your much better served going with a Oxy tourch set up with a Rosebud , or getting or making a Propane Forge, to where you can hold and manipulate the blade during the hardening cycle. Also a Pyrometer is absolutly nessesary as is a MAGNET for testing Critical Temp.

my .02
Allen

[This message has been edited by Allen Blade (edited 02-23-2000).]
 
I don't even know how to respond to this -- I'm speechless. Neither I, nor any of the Master Bladesmiths I've studied under in the last several years have any trouble getting blades from the heat treating furnace to the quench in time to achieve maximum hardness with fine grain structure.

So I'll just say what they always say to me, "My way is certainly not the only way, or necessarily the best way, but it works for me".

I respect your opinion, and appreciate the input.
 
in the first place a pyromitor is not very acurate a temp. controler is when your oven is 1500 then put the knife in an when its red all the way thru quench in oil this has worked for me for about 6000 blades

------------------
All that is not Given Is Lost
 
I just wanted to say thanks for your replies to may question. It is really great having a place like this to go and get advise from people that have been there done that.I just started making knives this January but I'm already hooked. They're even in my dreams. Also wanted to say that from what I've seen knife makers in general are good people,willing to help others any way they can, and this is very uncommon in today's society. Thanks
smile.gif
 
i've used dymondwood ,very nice stuff,and all i did was buff after shapeing with a grinder .polish's up very nice as far as i know because of the epoxy no need to do any thing else hope this help's you .
david lovins.
 
I heat treated 3 knives (01 steel) this past weekend. I did this heat trea at home using a homemade propane fish fryer. I tried heating the blades to critical temp but I could not get the entire blade hot enough at one time, so I made a little oven out of regular brick (I didn't have any fire brick). This worked great. I got up to crtical temp. in less than 2 minutes. I edge quenched in transmission fluid heated to 120 deg. I then tempered the blades in my toaster oven preheated to 400 deg. for one hour. I had tested the temp of the oven earlier with a thermometer. Anyway I tested the hardness at work and the edge tested at 61rc, the back tested at 43rc. I just wanted to know If my procedure sounds good, or could it be improved upon.
 
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