Category: How To

Rockwell Metal Hardness Charts

Rockwell Hardness Charts for Metals

Choosing a Rockwell Hardness Scale

Below are a few charts that will help you choose the proper set up for your Ames Rockwell portable hardness tester. The charts cover the following :

All information included in this article is found in the Ames Tester Manual. Download it here.

Material to be tested – 

Very hard metals, soft and hard steel, aluminum, brass, and thinner materials can all be tested with our testers.

Brass and aluminum alloys can be handled by using a 1/16 ball

The penetrator that is needed – 

Very hard metals like tungsten carbide, and thin steel needs to be tested using a Diamond penetrator.

Brass and aluminum alloys can be handled by using a 1/16 ball

Brass and aluminum alloys can be handled by using a 1/16 ball

The major load to be applied – 

Your tester is guaranteed to +/- 1 point Rockwell. When using this tester, you must use extreme care to position the pointer exactly on the minor and major load marks.

Lastly, the correct Barrel dial setting – 

The upper line of the barrel’s hardness scales should be exactly aligned beneath the hairline on the magnifier.

Metal hardness chart scale Rockwell Metal Hardness Charts

Here are some commonly used scales on our models.

Frequently Used Rockwell Scales

Please contact us with any questions regarding proper maintenance and set up of our Rockwell testers.

 

Measuring Hardness Rockwell Scale

Hardness Testing in Rockwell Scales

Hardness Testing – Rockwell scales

Measuring Hardness Rockwell Scale

Rockwell Hardness testing is a system for determining the hardness of metals and alloys of all kinds. The American Society for Testing and Materials (ASTM) has established a standard recognized worldwide to help manufacturers maintain the qualities they want in their products.

ASTM Standards E-18 and E-110 defines the test method and parameters for a valid test using portable hardness testers. Following is a general description of the method. A spheroconical diamond penetrator or a carbide ball penetrator is forced into the surface being tested at a predetermined pressure load. The hardness is read as a function of the depth of penetration.

To overcome errors in measurement, two pressure loads are applied in sequence. The first, a minor load is applied and the readout dial is “zeroed” with the part being tested still under load. Then the major load is applied.  The penetrator is backed out to the minor load point to read the distance traveled. The hardness reading represents the additional depth of penetration beyond the minor load.  Tester accuracy is checked by running the test on specimens whose hardness has been certified by an independent testing laboratory. All Ames hardness testers perform genuine Rockwell Hardness tests, giving a direct Rockwell reading. Their accuracy meets or exceeds ASTM Standards E-18 and E-110. Each tester comes complete with test specimens to assure continued accuracy. 

*All Ames testers are
factory lubricated. Do not
attempt additional lubrication.
Keep the tester dry and free
from oil. Store in the case
provided. When necessary,
wipe with a commercial
cleaner.

Maintaining accuracy with a portable Rockwell hardness tester

All AMES Hardness Testers, whether in constant use or not, require accuracy checks. To check accuracy, take the average of 5 readings on the test block. The readings on the barrel dial should agree with the marking on the test block, within +/- 1 point.
Further, to guarantee the accuracy of your tester, it is recommended that tests be made in high, medium, and low ranges. For example, C Scale, C-63, C-50, and C-28. Once per year, your tester needs to be factory calibrated. 

The distance between the center of two adjacent indentations shall be at least three times the diameter of
the indentation.  The distance from the center of any indentation to an edge of the test piece shall be at least two and a half times the diameter of the indentation. In other words, keep indentations 3 diameters apart. Indentations can only be made on one side of the test block.

Please check out our penetrators for hardness testing by clicking the link below

Penetrators for sale

Also check out more on how to properly use a portable Rockwell tester by following the link below

How to properly use a Ames Rockwell Hardness Tester

You may also contact us with any questions you may have. 

 

 

 

Rockwell-Metal-Hardness-Tester-Calibration

Portable Rockwell Hardness Tester Calibration – An Infographic

Rockwell-Metal-Hardness-Tester-Calibration

 

Don’t forget to calibrate your Ames Rockwell Tester once a year for continued accuracy

To get your Ames Tester calibrated or repaired please ship it to:

Stillion Industries
2055 N. Lima Center Rd.
Dexter MI 48130
United States

Please be sure to put your contact information in with the tester shipment.

Metal Rockwell Hardness Testing

How to Test the Hardness of Steel

Rockwell Hardness testing can be used for determining the hardness of soft and harder metals including steel. The American Society for Testing and Materials (ASTM) has established a standard recognized worldwide to help manufacturers maintain the qualities they want in their products.  ASTM Standards E-18 and E-110 defines the test method and parameters for a valid test using portable hardness testers. Rockwell hardness testing is a way of measuring the hardness of steel. Hardness means resistance to penetration. This test gets its name from Stanley P. Rockwell who invented the test and the original hardness testing machines.

Using the Rockwell method to test steel hardness

The Rockwell hardness testing of steel parts is done by applying loads to parts via either a tungsten carbide ball or a  diamond indenter.  The surface of the steel part has to be ready before the testing can begin.  If it is not, the chances of inaccurate readings rise.

Next, a light load is applied to the indenter or penetrator (usually either 3 or 5 kgf) to zero out the portable Rockwell hardness tester. Next, a heavy load ( from 15 kgf to 150 kgf) is applied and held for a period of time.

The length the indenter traveled from the application of the light load to the release of the heavy load is documented and used to determine the hardness of the steel

Rockwell hardness is determined by measuring the distance traveled by an indenter when a heavy load is applied to a heat-treated part. The Rockwell method is the most common and accurate way to get a calculation on the hardness of steel

Take a look at the video below for further instructions on using an Ames portable Rockwell hardness tester.

Further reading

What metals can Rockwell hardness testers be used with?

 

How To Use A Rockwell Portable Hardness Tester

Using An Ames Portable Metal Hardness Tester

Find more helpful videos on our youtube channel. Below is a transcript of the above video.  If you have any questions or need more information on our portable Rockwell testers than contact us here.

We’re going to be testing a customer’s sample piece on her Model 1 a standard Ames portable hardness tester.  The purpose of this demonstration is to show you just how easy it is to operate the tester as a sample piece or using a small clip. It is a hard material spring-type steel.  I’m using a diamond penetrator for the flat Anvil.   I’m going to be measuring in the C scale which requires a 10-kg minor load and I’ve got a  150 kg major load.  First thing I want to do is initialize the Dow indicator Itself by rotating the setting of the stylus of the indicator. Next we’re going to trap the part between the Anvil and the penetrator and I’m going to establish my 10 kg. load. Simply do that by rotating the handwheel and the pin correctly. Next we want to establish the zeo point on the tester itself. To do that we  rotate barrel down and rest the pin directly on the magnifer. Next we will rotate the handwheel to 150. Once that is set, reverse the handwheel back to the set point. What you see is the C scale numbers in black and B scale numbers in red. We are looking at the C scale.  You can see the line underneath the number 40 there’s a thick line and then off on the left hand side there’s little hash marks each one of those small hash marks is 2 points.  The large broad line underneath the number itself is the whole number or in this case 40.  You can see it set up in 10 point increments.  So what we’re looking at is 40 which is the black line underneath the 40 and then we’re sitting right between the broad and hash mark which makes it a 41.  We want to thank you for your attention should you have questions please feel free to contact us by email telephone.

Below are a few videos featuring tips on how to use a Portable Ames Rockwell Hardness Tester. Make sure  to tighten extensions, penetrator and anvil. Also make sure the gage is set to the dot. When used correctly our metal  hardness testers are reliable for testing metals and plastics.

If you should have any questions on our portable hardness testers please contact us here.

The first thing we are going to do is, with no load applied we want to lift this needle and make sure it’s below that set mark and pointed right at the dot. The next thing we’re going to do is just make sure all our components are tight so starting with the anvil, the extension and the anvil adapter and finally our penetrator, just make sure all of those are finger tight.

7 Things you Should and Should Not Do When Caring For Your Rockwell Tester

Your Ames portable hardness tester is a precious instrument.  As with any tool, proper care and maintenance is essential to maintain accurate testing results.  Remember, annual calibration is essential to properly maintaining your teseter.  Our metal hardness testers and accessories are machined, assembled and calibrated in our facility located in Dexter Michigan.

Ames Portable Hardness Testers are Made in Michigan

We have compiled the following list of do’s and don’ts to protect your hardness testing machine and keep it in the best working order.

7 Things You Should Do to Properly Care for your Ames Portable Tester:

  • Spray WD- 40 on a soft towel to clean your tester and test blocks
  • Make sure the Penetrator, extensions, and anvils are tightly secured
  • Store your test blocks in the plastic bag that is provided
  • Store your Rockwell tester in a safe location
  • Send your tester back for a yearly cleaning and re- calibration (if needed)
  • Only use the appropriate anvil for the application.
  • Perform regular tests on your Ames Tester to ensure accuracy
    Ames 4-4 portable hardness tester with manual

7 Things you Should Not Do to Your Ames Portable Tester:

  • Never apply oil directly on the tester
  • Do not drop or bang your tester
  • Never exceed major loads
  • Never use both sides of the test blocks. (one side only)
  • Do not retract the spindle past the threads of the penetrator
  • Never bang the tip of the diamond into the part or test block
  • Do not over or under shoot the minor or major loads

Your Ames Portable Hardness Tester is guaranteed to last for years if you follow these recommendations.  Be sure to follow the directions in the manual included with your tester.  Store your tester and testing blocks in the case provided when it is not in use.  As recommended by ASTM, perform regular accuracy checks to your tester to ensure the readings are accurate.

This blog was updated on December 14, 2021

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