Brinell Hardness Testing Reader: Manual or Automatic

KingScopeKingScope 100KingScan IVe
Brinell Hardness Testing Reader: Manual or Automatic

Posted on 31Jul

Reading Brinell Impressions

The first thing to consider when choosing a Brinell reading device is: how accurate a Brinell Reading you need and then consider if you want to read the impression manually or automatically?   Is a reading to the nearest tenth of a mm sufficient or do you need greater accuracy in your readings?

Manual reading is easy and straightforward.  You look through the lenses, focus the optics, position in the lens on the impression and read the result in mm.  The result in mm is then converted to HBW (Hardness Brinell) by looking up the mm measurement and the table provides the hardness.

Automatic reading uses a digital camera which shoot the image and does the calculations for you and tells you the diameter of the impression in mm and also the HBW (Hardness Brinell) number.  Automatic readers reduce the opportunity for human error and provide greater precision in the readings with readings measured to the .01mm. They also eliminate the need for the Brinell table lookup because the automatic reader does the calculation for you and provides you the Brinell hardness level.

Manual is easier and less expensive up front.  However, the other consideration is the potential for human error and the reproduce-ability of results.  The human eye and interpretation play a much larger role in handheld results than in automatic results and the time savings may justify the purchase of an automated reading device.  Additional considerations come from the ASTM E10 specification which defines two types of devices; type A and type B. 

ASTM E10 Considerations

KingScope Brinell Hardness Testing
KingScope
kingscope100 Brinell Hardness Testing
KingScope 100

 

Automatic Microscope for Brinell Hardness Testing
KingScan

Measurement Device

The measurement device used for the measurement of the diameter of Brinell indentations may be an integral part of the hardness machine or a separate stand-alone instrument. The allowable measurement devices are classified into two types.

Type A 

The Type A device includes microscopes having movable measuring lines with some type of indicator or computerized measuring system, or an image analysis system.

Type B 

The Type B device is a hand-held microscope with fixed measuring lines. Type B devices shall not be used for measuring indentations made with 2.5 mm and 1 mm ball indenters.

Note the limitations on the use of handheld scopes as it pertains to smaller indentations.

King Tester Readers 

King offers both handheld and automatic reading systems.  We have two Type A devices; the KingScan which is computerized and fully automatic and the KingScope 100 which is handheld.  For Type B handheld we offer the KingScope which has been and continues to be the industry preference for a handheld reader.


Choosing the Right Test Block

Posted on 31Jul

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.

 


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 King@Kingtester.com or by phone at +1 610 – 279 – 6010


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