1084 As-Quenched hardness and testing un-level pieces

[silver_pilate]

Edro came by the shop today and we heat treated a blade he had of Aldo's 1084. We normalized then heated to 1500, held long enough for everything to equalize, and quenched in Park's 50 at 100 degrees. It came out straight and looking good. The file test passed with flying colors, so I pulled out the handy dandy new (for me) RC tester I picked up the other day.

At first I was reading in the 40's. Ehhh....not good. Then I realized that the tang had been tapered and was preventing an accurate test. I shimmed the piece and was able to get more accurate readings of around 65RC.

First question: what is the expected as-quenched hardness of 1084?

Next: how do you guys test hardness on tapered pieces. I didn't want to test at the flat ricasso and leave a visible mark, so I was testing on the tang which we fully hardened. I know shimming isn't the best way either as it allows flex to occur. What I was thinking was to take a block of steel as an "anvil" and clamp the tang to it so that it is flat against the block. Then, place that anvil in a drill press vice and adjust it so that the tang is perpendicular to the tester. What do you guys do?

Thanks!

--nathan

 

[cotdt]

Expected for 1084 is 66 rc but 65 rc looks good to me.

What happens if you heat treat a random piece of 1084 and water quench, measure the hardness?

 

[silver_pilate]

Well the flex and uneveness of the shim likely explains the point of hardness missing, and the last 3 tests all were right around 65. And now that I think about it, the tester was reading about 1-2 points low on the test block. Not sure why I didn't adjust it.

Cotdt, I'd expect similar results in water as in #50, but I'll have to give it a go now that I've got the tester.

--Nathan

 

[69_knives]

What I would do is make your own test block/s; heat treat it/them however you like including temper, keep records of how they were heat treated and mark them with the RC value and their reference data (the stuff you wrote down) number. Then you know exactly how to HT that steel to get that result and you save wear and tear on your RC tester.

 

[silver_pilate]

That's definitely a good idea, and when I get some free shop time, I'll have to get some small blocks made and labeled. Thanks for the thought.

--nathan