Metal Hardness Tester

[NCBoy]

I hear on the site that many of the makers have something that tests the heat treated hardness of the steel. What have seen is that these are very expensive pieces of equipment. What are you using to testt the hardness and how much does it cost?

[Ray Rogers]

The best way is with a hardness tester. New ones cost $600 to $1000 for the most popular Chinese model that everyone seems to sell. But, keep your eyes open in the Classified ads and on eBay as used ones turn up pretty often. Take note that using a hardness tester is a technological art. In other words, it takes practice and a little skill to use it effectively.

All that being as it is, it isn't absolutely necessary for you to have one. Hardness is, after all, just a number. It tells you that you probably did things about right in your heat treat process but thoroughly testing your blades - including breaking a few - will also tell you if your heat treatment is right or not ...

[NCBoy]

Ray, thanks for your comments. You support us Newbys and that is awesome. Where can I go to learn about the testting techniques you use? I am not familiar with them.

[Ray Rogers]

There is no "one size fits all" set of testing steps but there are a number of common tests. Which tests you use will depend on the type of knife you're testing and your intended use for the knife. For instance, there isn't much point in chopping a 2x4 with a small skinning knife. You can Search this forum for details on how some of these tests are done but most will be obvious. I'm sure other guys will come along and add what I overlook but here's a start:

The brass rod test. Roll the edge and/or chop the rod.

Chop through a pine 2x4

Slice hemp rope (count the slices, compare to a blade you really like)

Slice cardboard (good test for edge holding, the clay in cardboard is very abrasive)

Stab a stump, twist the tip out of the wood

Split firewood (I hammer thin blades through a 12" long, 3 or 4" diameter piece of firewood lengthwise)

Cut free standing soda cans or water bottles (good edge geometry test)

Of course, real world testing by experts is desirable (my chef's knives get used by real chefs, for instance)

Periodically you should also break a blade to see the grain structure to make sure your HT is on target.

Basically, you do this kind of thing and keep track of the results to compare your blades against the performance of some blade you admire. There are no absolutes, you can't ask another maker how many cuts they got in cardboard because the cardboard they used is likely different than yours, their blade length different, etc. But, without some sort of serious testing we can't know if we have really made a knife or not ...

[NCBoy]

Thanks Ray

[copkevin]

Thanks for the info