Who all hardness test their knives?

E

ER Sheldon

Joined
Dec 21, 2020
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19
For those that do their own heat treating, do you complete Rockwell testing on your knives? Do most of your customers expect it?
 
I just got a hardness tester a few weeks back so I can say I do now. I’m a hobbyist and I wouldn’t say that people who have bought from me expect it but knife enthusiasts will ask what the hardness is sometimes. Your average customer who is buying their first custom knife probably won’t. For me it was to satisfy myself and to enable more testing of heat treat procedures with my equipment.
 
I'm a new maker and I just got my own hardness tester. Prior to that I had a buddy who has a tester at his business testing for me. Glad to be doing it all right here at home now. I do it for my piece of mind and I do think it's important to ensure your making the best possible product.
 
I usually test one out of every batch to be sure everything is where its supposed to be. When using a new steel I use it a whole lot to get my process dialed in.
 
I test 1-2 per batch that’s heat treated. For me that’s 6-7 knives. I think it’s the best way to know for sure that my heat treating process went as planned. A file will skate on 57rc and 61rc and that’s a huge difference.
 
Yes. And after each temper to make sure I'm hitting the exact number I want. I often do 4 tempers to creep up on (more accurately down on) the number I want. Only takes a few seconds do why not. A couple points can make all the difference in the world
 
I don't have a tester (and probably won't for a while, no used ones on the market around here). I made test coupons for the steels I use and had them tested, so at least I know the process is ok.

Mark
 
It seems a lot of people buying knives and many makers are not to concerned about hardness. I offered to check knife hardness for a couple makers that sell many more knives than I do after conversations they started, they never sent me any samples so all I can conclude is they really do not care, what a shame.

I check every knife, every time. My clients expect it from me and my standards.
 
I don’t know if the majority of every day customers care or even know very much about RC numbers. But on the other hand someone that makes knives for resell should know what the hardness is. It give you a quality control point during manufacture to insure the customer gets a knife that will meet or exceed your Claims and their expectations. Majority of every day guys buying custom knives do so because thy believe thy will get a better quality knife then what thy can buy in the store. So you need to do what ever you can to make sure you live up to your side of the process.

I’m not saying a hardness tester is a must but it sure makes heat treating to a consistent result much more attainable. If you are just heat treating and blindly tempering off a temper chart you found on line you could be off by a lot and not even know. I would go as far to say you could be off by up to 3rc. And if your using a kitchen or toster oven the sky is the limit on the percentage of error on hardness.

Sure you can go and extensively test each blade to make sure it performs as you expect. Or you can dial in a good heat treat with your hardness tester on the first go around and just rinse and repeat for each knife. But to each there own and I know that some of some very popular smiths that do/did not hardness test. But there is a big difference between a smith that has 10-30 years of experience and a new guy with 0-1.


give your customers what thy are expecting to be buying and all will be good. How ever you do it is fine. Just make sure the quality you provide is top notch and the heat treat is dialed in for that customers use and blade geometry.
 
I personally do every knife just as a hobbyist. I do my own heat treat and want to know if my "recipe" or better yet my HT oven and temper oven are doing what I want them to do. BUT if I had a local machine shop or someone else that could check RH I'd go that route. My problem all the local machine shops I contacted said yes we have a RH tester. But when I went to them it was up on a shelve covered in dust (bad sign if you know anything about RH testers) or on a bench that they had to clear a path to to get to! I'm guessing they didn't use often or never and I left not knowing if I was getting true readings.

I guess it goes with the price quality of your knives. If someone is paying a premium price for a quality custom knife I'd expect the perfect RH for given steel. If I'm buying from a local back yard FIF viewer I wouldn't expect and I wouldn't pay above dollar store pricing.

Bottom line if you have a local shop that could reliably test or a knife maker that would check for you every so often depending on how many knives you make a month or year it would be the last thing on my list of wants depending on what you are asking for your knives if you sell. But I love knowing every knife that leaves my shop is heat treated to the best of abilities. To be honest real world use should tell you if your remotely in the ball park if your knife is living up to what it should do. A few years back a friend I made a knife for went out west and used a knife I made him. He came back with glowing reports of how many animals he used that knife on before he said it became dull. That along with the known RH of the knife along with the design of my knife knew I was spot on.
 
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Yes, every knife I heat treat gets tested. A number of months ago my thermocouple readings were off and so steel that I had previously heat treated successfully was coming out soft because the oven was cooler than expected. If I didn't test every blade I wouldn't have caught this and replaced my thermocouple.
 
I use a tester at work. So, it's pretty impractical for me to do every blade. BUT, I do test several of each heat number, and buy the biggest piece and as much as that heat that I can afford. So it's pretty easy to test half of the knives out of each heat.

I'd simply LOVE to have one at home for testing HT schedules. It's a pain to start a new steel or batch without it. I'm open to suggestions for testers. The Grizzly is the cheapest I've found.
 
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