Importance of Hardness Testing

Brinell TestersRockwell Testers
Importance of Hardness Testing

Posted on 25Oct

What is hardness in metals?

Hardness is the property of a material that allows it to resist permanent distortion, penetration, indentation, and scratching. Therefore, hardness is important from an engineering point of view because resistance to wear by either friction or erosion from steam, oil, and water generally increases with hardness. The hardness of material refers to its ability to resist wear, tear, scratching, and abrasion cutting.

What is hardness testing?

The process of testing surface hardness by applying a specific, known force on the testing surface, allowing us to know the strength of metal, is called hardness testing. Hardness testing lets us know how much pressure a material can withstand before it changes in shape.

It is very important to know the hardness of materials when looking for a suitable material for a specific environment and use. For instance, using metal in an environment that may include small particles that can induce material wear. Soft materials suffer indentations, while hard ones are more resistant to any change in shape.

There are different types of hardness testing, and each type of test is unique and designed for different purposes.

These different types of hardness tests help us get readings to measure hardness in different ways. For example, for the Brinell test method, we use indentation diameter to determine the hardness of the material, for a Rockwell test we use the depth of impression, for a Vickers test we use indentation and apical angle of 136 degrees to measure hardness, and a Knoop test is mostly used on very thin materials to determine hardness.

Why is hardness testing used?

The various hardness testing can be used for the following purposes.

Quality inspections
Many metals suppliers and metal manufacturers use different types of metal hardness testing to ensure the quality purposes. Typically, companies will test the hardness of material received from suppliers to ensure that material meets the quality standards specified, and specifically the desired hardness required for the use of the material.

Measuring the specific hardness needed
Often material is heat-treated to achieve the desired level of hardness that may be higher or lower than the original hardness of the material. In this case, after the material has been heat-treated, it is important to test the hardness to verify that the heat treatment achieved the desired objective of hardening or softening the material to the desired specification.

Maintain consistency
During production, it may be desirable to sample the parts or the material to ensure hardness consistency in the process.

Certifying your metals
Hardness testing is used by different industries, including oil and gas, to certify the hardness of the metal as per an API (American Petroleum Institute) or ASTM standard.

King Tester, A Poem

Posted on 23Aug


Don’t hurt your back
Leave the steel on the rack
Just slide it an inch
And let the King take a pinch
You’ll work smarter, not harder
And beat the rest to the door
You can test on a bench
Or right off the floor
Just clamp on the tester
In any direction
The mark that it makes
Will help your selection
Next check the wall chart
And then you will know
If the steel that you have
Is ready to go
So get the right tool for the job
One you know you can trust
You’ll be finished in minutes
And your back, you won’t bust
King: We got your back

– Bill Daley, King Tester Renaissance Man

Choosing the Right Test Block

Posted on 31Jul

Choosing the Right Test Block : Many people operate under a misconception they must use a test block equivalent in hardness to the parts or samples they are testing.  This is not the case. While it is wise to choose a test block within a reasonable range of the same hardness you do not need to match the hardness exactly.  The Test Block is used to indirectly verify the force being applied by the tester is equivalent to the calibrated force of the tester. This is done by using the tester to apply force to a known metal hardness (the Test Block).  The result is then compared to the master indentations on the Test Block to determine if the Tester is applying accurate pressure.

Some of the factors to consider when choosing the right test block are

  1. Hardness
  2. Conformance with ASTM standards
  3. Size
  4. Ease of Use
  5. Record keeping
  6. Cost
Let’s take these factors one at a time

Hardness is the known hardness of the Test Block as certified.  Because the hardness of the block is known it can be used to determine the size diameter of indentation made at a given level of force.  The Test Block should be within a reasonable range of the hardness of the material to be tested but it does not nee to be exact. Why? Because the tester is being verified for the force it applies to a known hardness.  It will apply the same force regardless of the hardness of the test block. Reasonable guidance is to purchase a test block +/- 50 HBW from your parts target hardness. if you want to tighten the range; you can but the result will be the same.  The only time the result may vary would be a function of dwell time on softer metal which could influence results.

Conformance with ASTM  standards is important and in some case vital.  This means the test Block has a limited number of indentation opportunities as a function of the requirements for spacing as laid out in ASTM E10.  You may only use the designated test surface (no flipping the test block to double the number of indents. King Tester has taken the guess work out of meeting ASTM standards for you with our patented test block design which makes it simple to punch in the right places.

Test blocks come in different sizes and size only makes a difference in so far as larger sizes allow you to reduce you cost of verification by more effectively using the real estate on the Test Block. King Tester provides both 2×6 and 4×4 sizes in a wide range of hardnesses.

Ease of use is important for a couple of reasons.  The ability to set the Test Block in the right place to make the proper indentation is easier with a grid design. The grid design allows the user to follow the markings to place the test block in the proper spot for the indentation.  Following the grid also reduces the time it takes to do the verification.

Record keeping is required to be able to establish the tester force was verified daily.  The King patented Test Block design contains an index which allow for easy tracking of tests taken. For example; test on Feb 1st was taken at location B2 and February 2nd was at B3 and so on. This replaces the sharpies and guess work and lends itself to more professional record keeping which pleases the auditors.

Cost is always a consideration and best way to measure cost is ona per indentation basis.  What is the cost for daily verification? A less expensive test block is nice but if it leads to wasted indentations and fewer indentation per block then the cost may be higher.  King’s patented Test Block design holds down your costs by managing your cost per indentation.


23 Years with King Tester

Posted on 30Jul

23 Years with King Tester : In July King Tester celebrated 23 years of Bill’s contribution to manufacturing and repairing King Portable Brinell Testers.  Bill is King Tester’s production manager, shipper extraordinaire and tagline specialist – a true King Tester renaissance man.   

Over the course of the last 23 years, Bill has seen just about everything and anything that can be done to a King Portable Brinell Tester and its face.  Bill is as enthusiastic about King Portable Brinell Testers today as he was when he started. “Andrew King saw a need 80 years ago for a portable Brinell tester and if someone found a better way to bring the Brinell testing to you, they would have done it by now,” said Bill.  

King Tester meticulously keeps track of every interaction it has with every tester – whether it be through physical forms like when Bill started or electronically in today’s digital world.  Bill has seen over 6,000 King Portable Brinell Testers leave King Tester’s doors in his 23 years.

When properly cared for and maintained, the King Portable Brinell Tester lasts for decades and is the ultimate workhorse for Brinell testing in many industries including oil and gas, foundries, defense, aerospace, automotive, heat treaters, rail and many more.  

“The fact that King products are such a small but important part of our manufacturing world and help to build so much infrastructure is really incredible,”  Bill said, “Our customers can’t do what they need to do and build what they need to build without these King products. So it is pretty cool to be a crucial cog in the wheel.”            

With King Tester’s ISO-17025 certification, it carries on a long tradition of over 80 years of commitment to the highest quality testers on the market.  Bill is very passionate about Daily Verification, “It is the only way to get a real depiction of its accuracy and reliability. It is essentially like backing up your computer.”  Daily Verification and yearly Indirect Verification increase the longevity of your King Portable Brinell Tester’s accuracy, reliability and durability.

King Tester continues to be the crown jewel for metal hardness testing.   King Tester recently introduced its new KingScope100™, an ASTM Type A reader and innovation in Brinell indent reading.  King Tester offers a wide range of metal hardness testing equipment and related products to customers wo

Officially A2LA Accredited Laboratory

Posted on 02Jun

The month of May just started and big things are already happening at King Tester.

King Tester Corporation received its accreditation to ISO/IEC 17025. King Tester received the ISO 17025 accreditation from American Association for Laboratory Accreditation (A2LA), the only independent internationally recognized accreditation body in the United States.

The accreditation comes after an extensive and comprehensive audit of King Tester’s quality program and procedures. In order to receive accreditation, King Tester must meet (and continue to meet) the highest international standards of rigorous quality evaluation for product and service quality.

James Knight, president of King Tester Corporation said, “We are pleased to receive this recognition for our products and services. This certification provides tangible independent validation of our continuing commitment to the highest quality testing equipment and products for our customers.”

This accreditation further legitimizes King Tester as not only a premier manufacturer of metal hardness testers, but now as a calibration laboratory for metal hardness testers.

King Tester continues to build on over 80 years of manufacturing and service to metal producers and users worldwide. King Tester recently introduced its new KingScope100™ as an innovation in Brinell measuring devices. King Tester offers a wide range of metal hardness testing equipment and related products to customers worldwide.

King Tester was founded in 1936 by Andrew King to satisfy the need for a portable full load Brinell Hardness Tester. King Tester manufactures King Portable Brinell hardness testers and related Brinell products. King Tester’s customers range from the largest multinationals to small privately owned metal processors. King serves a wide range of industries including aerospace, rail, auto, foundries, steel and aluminium mills, calibration labs, oil and gas, heat treaters, wear parts, military, infrastructure, construction and utilities.

Brinell testing for large parts

Posted on 10Apr

Often large metal parts require Brinell testing to confirm the hardness of the metal and these large parts can prove to be a significant challenge when testing the hardness of metal. A large part by its very nature is difficult to reach and difficult to test. Portable testers can be very helpful in testing large parts because they provide the flexibility to be able to test the part where it is located instead of having to move the part to the location of the tester. However, some large parts can be difficult to test even with the use of portable testers. Quite often this is a result of the accessibility of the test location.

Large parts might include pipes where the desired test location is not readily accessible from the edge of the pipe. Large castings may also require testing in locations which cannot be accessed when using the standard base.

To address this challenge, King Tester has developed specialized basis to allow the tester to be used to test in the desired location. One of the special bases which is particularly versatile we refer to as the “King Chain Adapter” or a “King CA base”. This special base allows the flexibility to move the test head into the base which can then be easily adapted through the use of a chain to test a large part at the desired location.

There is no practical limitation to the length of chain which can be used and therefore with the King chain adapter base the King portable Brinell hardness tester is easily adapted to be able to test even the largest parts in locations as desired.

The King Tester head used with the King Tester Chain Adapter base allows the user to place a full load (up to 3000 kg force) onto the large part in the desired testing location and there are no compromises in the accuracy or precision of the results from the King tester had when used in conjunction with the King tester chain adapter base.

You can be certain when you use the King Portable Brinell hardness tester in conjunction with the King Chain Adapter Base that you are conducting a test which fully conforms with ASTM standards.

King Tester works with customers on a daily basis to help them meet their testing needs. For more information, please contact us by email at or by phone at +1 610 – 279 – 6010

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