Archive: January 21, 2023

Hardness Testing for Knife Makers

Whether you are a hobby saw or knife maker, you may be wondering if you can use an old Rockwell hardness tester to test the hardness of your blades.  Many forums are full of comments from people just like you who have found old hardness testers at garage sales and want to know how to use them to verify their bald hardness.  There is a learning curve to using an Ames hardness tester, just like with any new measuring device. You can download the user manual for Ames testers for free and you will find all of the conversion charts you need to accurate reading no matter what you are testing.

Check out this in depth Demo of an Ames Hardness Tester from an Advanced Knife Maker:

As a knife maker, you may have used a hardness tester to perform hardness tests on your knives or saw blades.  Ames portable hardness testers are a preferred model for blade makers to perform quick hardness tests.  Many knife makers may not have the budget to purchase a new Ames Portable Hardness Tester.  Used testers available on eBay and Facebook marketplace can be appealing because of their discounted price.  It is important to check the serial number of a used hardness tester before you purchase it.  Old hardness testers may serve the purpose you are looking for: A basic hardness test.  However, it is important to know that you may not be able to have the tester certified when it is repaired if it is too old.

The frames of old hardness testers can fatigue, which will not allow the tester to perform an accurate hardness test, even with calibration you may find that the hardness readings don’t stay accurate.  This is why we recommend you look for hardness testers that have a serial number of 12000 or newer.  You should always turn the tester over and check the sticker on the back.  Every Ames factory-calibrated tester has a sticker telling you when the next calibration should be performed.  Another way to determine if your used tester is a good buy is to perform accuracy testing.  You can use the test blocks provided with the tester to make sure the readings are accurate.  Make sure you are using the correct penetrator for the scale you are reading in.

Grismo Knives demonstrates Testing Blade Hardness with Ames Testers: