Hardness tester.

KnuckleDownKnives

KnuckleDownKnives

Time to make the doughnuts..
Joined
Feb 12, 2015
Messages
1,715
Well I'm i need of getting an O1 knife tested because after HT, 18 mins at 1475-1500 and quench in 125* canola oil it seems a file is biting in some and it's my first O1 to go out the door and I want it right. I contacted JT and he's up for it but the time to get it to him in back if it tests good is putting me well over time what I told my customer I could get it to him in. So yesterday I called around and found a shop 3 miles from my work that has a tester, but recommended me contacting the tech collage 1/2 mile from my office. So after trying to contact them for the last 2 days to no avail, I call the first shop back and he's going to test it for me tomorrow. He also said he has their old tester that worked up until the day they got their new one and will sell it to me if I want for $50.00. He said it tests in C scale and is a diamond tip tester and has all the parts. So for $50 I'm going to chance it and pick it up either way. Worst case scenario I'll have a $50 paper weight...
 
All the O1 I have used seems to have a much thicker layer of decarb as compared to 1084 or 15N20 that I normally use. It always catches me off guard at first.
 
Knife freaky said:
I don't see how you can beat that for $50! Those boogers are generally pretty pricey! But then again I know next to nothing about hardness testers.
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Yes I know the price tags, I've been pricing them out for about a year now and just haven't been able to buy one as I've had more important things I needed. Right now I feel like a kid waiting on Christmas eve. I think he's trying to hook me up cause we had a really long nice conversation yesterday about me making knives and looking for a vendor close by that can test knives for me and one of his friends that makes them that owns one of the really huge machine shops in town.
 
E.Carlson said:
All the O1 I have used seems to have a much thicker layer of decarb as compared to 1084 or 15N20 that I normally use. It always catches me off guard at first.
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I haven't done enough O1 to know, I have another O1 blade on the shelf that's HT'd and when I testes it out of quench it didn't act like this at all, so that's why it has me worried. My 1084 HT I've got enough knives out there that have been used, I don't know their numbers, but the performance they have has been outstanding from what the owners report to me.
 
At worst case you might need to purchase "Test" blocks and possibly a Diamond Indenter (can be found on ebay) but that is a good deal. Make sure that the weights are locked down before transport and if its a bench model they are about 120-150 lbs. Ask if they have the manual in case you need to clean it up and check all parts are there. No more guessing and trusting a file for hardness:cool:
 
Well, for test blocks "IF" you're a cheapskate like me, you can use 1/4" lathe tool bits. Those are going to be in the 61/62 Rc "range" - broadly range. Take a couple or 3 with you to the machine shop, get them to test the lathe tool bits and mark what the Rc is on each. There's your test blocks. Normally you'd have a test block in the 40-48 Rc range also, but for now the one 60 Rc range block would get you started. Then later, HT and temper a 1/4" block down to the 45ish range, have it tested. That would give you a good one for testing folder back springs.

You can always mail to me or other folks in the group to make test blocks for you. Happy to help.

Ken H>
 
I’d spend the money and get proper test blocks. Especially since you may have gotten a great deal on the hardness tester. I’m not trying to argue, but what’s the point of getting a hardness tester if you’re using lathe bits to compare your numbers to?
 
Josh Rider said:
I’d spend the money and get proper test blocks. Especially since you may have gotten a great deal on the hardness tester. I’m not trying to argue, but what’s the point of getting a hardness tester if you’re using lathe bits to compare your numbers to?
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Yes, at this point since I got the deal on the tester, I'd rather spend the money on certified blocks. Looks like one in the at around 60 and one at around 45 should do me???
 
On test blocks just get one in the 60 range and once you calibrate to that you are good to go the Tester will give you the reading of the material tested it doesn't care what you calibrated at. You want to make at least two calibration attempts to ensure you are dead nuts on...Test blocks usually +/- a Half RC so if you get a swing outside those numbers you need to clean the indenter with a lint free cloth and denatured alcohol and wipe down the pedestal. Also the test should be done with the blade perfectly flat and test on a Flat spot no rocking or movement or you will get bogus numbers.
 
Check ebay for test blocks. New ones are cheap, and used ones are cheaper.

Make some test blocks from knife thickness stock and do the HT in your oven. Before doing the HT, punch numbers/letters on the blocks #1 - O-1; #2 D-2; #3 1095; #4 1084: etc.. On one side of each block punch A and the other B. Make a record card on the blocks.
After HT, clean the A side off lightly with a 220 belt on the flat platen, to get a reference for the test with decarb....and grind the B clean to 220 grit for a finished blade hardness reference. This will tell you about the amount of decarb you are building up. These blocks reflect the results you get in your HT.
Once cleaned up, have someone with a good calibrated tester do tests on them and give you the results for both sides. It would be best if each ide was tested three times, and the average record. Put these values on the record card you made with the HT specs and block numbers. Keep the blocks and the card in a plastic storage box so you can find them when needed.
This way you will know what to expect from a certain program with YOUR equipment. The blocks can be used to test the tester as needed.

Now, about the file and your blade. You have to file it several time with a good force to clear the decarb. Usually on the second or third stroke the file will change pitch and slide along the edge. When hardness testing the blade, it should be done on a spot on the tang that has been ground clean and smooth to remove the decarb.
 
Stacy E. Apelt - Bladesmith said:
Check ebay for test blocks. New ones are cheap, and used ones are cheaper.

Make some test blocks from knife thickness stock and do the HT in your oven. Before doing the HT, punch numbers/letters on the blocks #1 - O-1; #2 D-2; #3 1095; #4 1084: etc.. On one side of each block punch A and the other B. Make a record card on the blocks.
After HT, clean the A side off lightly with a 220 belt on the flat platen, to get a reference for the test with decarb....and grind the B clean to 220 grit for a finished blade hardness reference. This will tell you about the amount of decarb you are building up. These blocks reflect the results you get in your HT.
Once cleaned up, have someone with a good calibrated tester do tests on them and give you the results for both sides. It would be best if each ide was tested three times, and the average record. Put these values on the record card you made with the HT specs and block numbers. Keep the blocks and the card in a plastic storage box so you can find them when needed.
This way you will know what to expect from a certain program with YOUR equipment. The blocks can be used to test the tester as needed.

Now, about the file and your blade. You have to file it several time with a good force to clear the decarb. Usually on the second or third stroke the file will change pitch and slide along the edge. When hardness testing the blade, it should be done on a spot on the tang that has been ground clean and smooth to remove the decarb.
Click to expand...

Thanks Stacy.

As far as my file test, I did it right on the corner where the blade will be that i left at .02" and the spine, and it pretty much chamfered the corners. this is the first time this has happened on any blade I've done out of quench.
 
Stacy E. Apelt - Bladesmith said:
Check ebay for test blocks. New ones are cheap, and used ones are cheaper.
Click to expand...

Right you are - I had checked a couple yrs ago and only found test blocks in the $60 to $100 range. Now I'm seeing them from $15 to $25 range. I guess like the diamond penetrators, used to be way over $100, now can be purchased for $10 to $15 shipped.
 
Well after messing with this for the last few hrs I'm pretty sure the indicator needs work or replacing. It seems it doesn't return to zero. Like the spring is week or something. It's kind of erratic. Even when removed. From what I can tell it's no more than dial indicator. At least that's what it appears to me. My actual dial indicator compared to this returns to zero fast and easy this seams to get to a certain point and drags.
 
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