Phase II hardness tester

$200? You stole it!
It would be nice to have test blocks from 59 to 63... but 60-62 would be enough probably.
 
T
Salem Straub said:
$200? You stole it!
It would be nice to have test blocks from 59 to 63... but 60-62 would be enough probably.
Click to expand...
Thanks for the tip. I think it may be reading a bit low. Several blades that should be 62 are reading 60. I tested an old U.S. diamond brand file, it read 64.
 
A test block should have no more range than .5Rc.
A 60.0 +/-0.5 block is a good one for checking a knife hardness tester.

The best, and cheapest, test blocks for you to use are to make up half a dozen 2X2" blocks from 1/4" 1084. Mark the with letters or numbers (A,B,C,1,2,3,etc.) HT them as a batch at 1500F in your oven. Sand the two main surface clean to 400 grit on a flat platen after quench. Keep A/1 as is, and temper the rest for one hour at 300F. Do separate second tempers at 300, 350, 400, 450, 500. Keep a record of the group with all HT specs, times, steps, etc. Touch up on the flat platen and send them to someone with a recently calibrated tester. Use a carbide/diamond scribe or engraver to mark each block with its hardness. This will give you a full range of test blocks for checking your tester and adjusting it.

Besides getting a good set of reference test blocks, this will give you a real world chart and data sheet of what hardness to expect in 1084 from your equipment at varying tempers.
 
Last edited:
Bigjohn said:
Stacy, who can calibrate a tester in our area?
Click to expand...
Look up metrology labs. I just got a tester a couple weeks ago and just learned all this. The dial indicator on mine needed cleaning as it sat up in storage for some years and got gummy. They took it apart cleaned it, installed new crystals lubed and calibrated it for $65. I'm waiting on getting some certified blocks and calibrating it myself, but a metrology lab can do it. Mines reading 3 points low pretty sure based off some blades I had tested on a calibrated tester.

I would recommend if you go this route to deliver it and pick it up from them yourself if you can as you don't have to worry about a delivery company letting it bounce around in a truck or something.
 
You must log in or register to reply here.
Back
Top