I have a Japanese bench tester that has worked fine for as long as I've
owned it (about 20 years) (it looks like the Mitutoyo tester if you have
seen one of those). I traded with a fellow-knifemaker for the Swiss portable
tester I had before that. I'd say the Swiss hand-held and the bench tester
were roughly equally accurate and repeatable. I can't comment on the Wilson
models, though they have always been the "standard" make, since I've never
used one. The diamond indenter is required for C scale readings, as you
probably know. I wouldn't pay a nickel for motorization, unless I was
running a heat treating shop. I never resented the few minutes it took to
take three hardness readings on a knife blank. Someone who has experience
with motorized units, may chime in and prove me wrong.

If you haven't heat treated your own work before, you are going to love the
freedom it brings, not having to decide in advance what the next twenty
blades are, batching them together for commercial treatment. Not to mention
the positive effect of having someone doing the heat treat that actually
gives a ****!

Where I would definitely spend a bit of money is on the controller, and on
adequate insulation of the box. My oven has a fiberfax hot face, which makes
a tremendous difference to the time it takes to get to temperatu 0 to
2000F in about 18 minutes, 15A 220V.

Good luck with the project,

Adam Smith
Midland, ON

----- Original Message -----
From: "Al MacDonald"
Newsgroups: rec.crafts.metalworking
Sent: Thursday, November 10, 2005 9:58 AM
Subject: Hardness tester


Greetings,

A friend and I are building a heat treating oven for his knife making
hobby and my general home machine shop. He wants to be able to test the
hardness of his knife before and after heat treating (C50-C55 range) and I
am interested in being able to test metal in general (anneal, machine,
reharden to Cxx various sized items that may surface to be worked on) so
we are looking at buying some kind of harness tester. I see lots of
larger Wilson and similar models on ebay but there are many different
models (3JR, 1JS, 3JS, 5JR, 12A, and huge variations on prices. Most come
with weights and some come with diamond and different sized ball
indenters, which I assume are all changeable for A/B/C scales. I haven't
run one of these machines before, and while the idea of various weights
vs. various sizes of penetrators makes sense, I'm assuming the plug in
cord and remarks of motors may be to raise and lower the penetrator gently
onto/into the test surface.

I also see some smaller portable models, but I have no idea on whether
they would work well enough to be worth buying.

My question is this: does anyone have any comments on specific
makes/models which would do what we want, or anything I should be looking
for (or looking out for) when buying a used tester? Thanks.

Al MacDonald


"Al MacDonald" wrote in message
news:QeJcf.118841$yS6.90917@clgrps12...
Greetings,

A friend and I are building a heat treating oven for his knife making
hobby and my general home machine shop. He wants to be able to test the
hardness of his knife before and after heat treating (C50-C55 range) and I
am interested in being able to test metal in general (anneal, machine,
reharden to Cxx various sized items that may surface to be worked on) so
we are looking at buying some kind of harness tester. I see lots of
larger Wilson and similar models on ebay but there are many different
models (3JR, 1JS, 3JS, 5JR, 12A, and huge variations on prices. Most come
with weights and some come with diamond and different sized ball
indenters, which I assume are all changeable for A/B/C scales. I haven't
run one of these machines before, and while the idea of various weights
vs. various sizes of penetrators makes sense, I'm assuming the plug in
cord and remarks of motors may be to raise and lower the penetrator gently
onto/into the test surface.

I also see some smaller portable models, but I have no idea on whether
they would work well enough to be worth buying.

My question is this: does anyone have any comments on specific
makes/models which would do what we want, or anything I should be looking
for (or looking out for) when buying a used tester? Thanks.

Al MacDonald