FAQs - Hardness Testers
Can I perform regular tests on my Superficial Rockwell tester?
No, can you not.
Can I perform superficial tests on my Regular Rockwell
No, you can not.
Can I use a carbide ball indenter on a block that was not calibrated with a carbide ball?
Yes, you can but your reading will be lower, up to 1 point lower than normal.
Can my Regular Rockwell tester be modified to perform superficial tests?
No, it can not. Unless it is a model 2000 tester. If it is, then it can be programmed to do superficial tests.
Can my Superficial Rockwell tester be modified to perform regular tasks?
No, it can not. Unless it is a model 2000 tester. If it is, then it can be programmed to do regular tests.
Do the weights in my dead weight tester actually weigh the amount stamped on them?
No, they do not. They are stacked in a cumulative fashion. For instance, on a regular scale Rockwell tester, the 60kg weight actually weighs 2230g or 1849g (depending on whether your power lever is iron or aluminum), the 100kg weight actually weighs 1600g and the 150kg weight actually weighs 2000g.
Do you have tips on shipping my dashpot or dead weight hardness tester?
First, do not turn the tester on its side, the oil will leak out. Second, remove the weights and pack separately. And last, wrap some foam or bubble wrap around the power lever to prevent it from movement. Yes, it can be strapped to a packing skid, just make sure you don't have any straps laid across the elevating screw. Remember to remove indenters, blocks and anvils as well.
Does the deformation during a test also extend outward?
Yes, so the distance near an edge or an adjacent indent is critical. ASTM recommends the distance from the center of an indentation and the nearest adjacent indentation be 3 times the diameter of the indentation. The distance between the center of an indentation to the nearest edge must be at least 2 ½ times the diameter of the indentation.
How do I know when my test block is no longer useful?
The useful life of a test block is determined by the population and proximity of the indentations. The distance between the center of any 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 block or test piece shall be at least two and a half times the diameter of the indentation. Tests are to be taken on the top side of the block only.
How do you run the Self Test feature on the U-Tronics printer?
To use the Self Test feature of the printer, start with the printer power ON, and set the printer to the Offline mode. Offline mode means only the Red light is lit, so if the Green light is ON, press the SEL button to turn it Off. Next, press and hold the LF button, then press the SEL button while still pressing the LF button. The printer should start printing a self test pattern so you can release both buttons once it starts printing. To stop the printing, press the SEL button or you can wait until the printer times out.
How frequently should I have my tester verified or calibrated?
We recommend that it be done annually.
How many tests will a Tukon 200 series with a Digital Filar option store?
It will store up to 1000 hardness values.
How often do I need to have my test block calibrated
There is no published specification at this time which mandates block recalibration
I have an auditor asking for software verification documentation and Instron accreditation information. Where can I find this information?
Instron software verification documentation, accreditations and certificates can be viewed and downloaded here
If a material is too thin to test alone, can I stack test pieces to increase thickness?
No, stacking one or more additional layers of metallic material together can not make up for an insufficient material thickness. The material flow between the layers will produce inaccurate measurements.
If I see an E error on the test screen of an M200 or M250 what is wrong?
If this is a new unit or you are testing a new test block for the first time, closely examine the test block to see if you have peeled off the thin film protective covering that comes with each test block. If you are testing another piece of metal check the settings of the tester to see if they match with the type of material of the test piece. Next take a test on your test block to see if the readings are OK. If they are not look to see if the ball leaves an indent in the test block surface. If it doesn't the tester may need service. Customer Service is 800-473-7838.
Is there a minimum depth requirement for testing a case hardened specimen on an M200 or M250?
Yes, the depth of the hardness layer on the surface of a heat treated work piece should be equal to or greater than 0.03 in. (0.8 mm). Otherwise, lower hardness values can result due to deformation and vibration of the work piece surface.
Is there a minimum thickness of a test piece when using an M200 or M250 handheld tester?
Yes, the minimum thickness of the work piece under test should be .125 in. (3mm) and it needs to be secured to a table or support.
Is there a surface roughness requirement of a test piece when measuring with an M200 or M250?
Yes, to eliminate measurement error which could result from the roughness of the test surface, the surface should be polished so that a metallic luster appears. The roughness (Ra) of the surface must be limited to less than or equal to 2 microns, which is the equivalent to a smoothness of V6 or above.
Is there a weight requirement for a test piece when using an M200 or M250 handheld tester?
Yes, a solid work piece that weighs more than 11 lbs. (5kg) can be tested directly. A work piece that weighs 6 to 11 lbs. (3-5kg) with cantilevers or a thin shell, should be fixed to a bearing or support which weighs over 11lbs. (5kg) to avoid bending, deformation, and displacement during testing. A work piece that weighs less than 4 lbs. (2kg) should be secured to a table or support. The surface between the work piece and the support must be clean, hard, and smooth. Apply Vaseline or yellow grease to the adjoining surfaces of the work piece and support. To secure the work piece, press the work piece firmly on the support, move the work piece back and forth to eliminate any air between the two surfaces.
It seems as though the testing is punching through the hardened material on a C scale
If the objective of the Rockwell test is to measure the hardness of a surface feature such as case hardening, the scale chosen should be based on the thickness of the hardened area. The depth of penetration of a Rockwell C scale hardness reading of C60 is .0032 inches while it's A scale equivalent of HRA 81.2 only reaches a depth of .0015 inches. Choosing a Superficial scale such as 15N would give you an equivalent depth of penetration of .0003 inches.
My 2000 tester forced the indenter through the material into the anvil during the test cycle
Having the indenter in contact with the material at the start of the test causes the problem. When the test cycle begins, the tester zero's the force on the indenter, (normally zero force). If the test material is in contact with the indenter, the tester zero's out that force and applies the load from that point. This can cause the indenter to drive deeper into or through the material. Raising the indenter up slightly to make sure that the material is not touching the indenter should correct this problem.
My Tukon 200 Series tester is hung in a Test Cycle and the Start Test light remains ON
Someone probably tried to turn the turret after a test was started. Do the following: 1. Turn off the power to the tester. 2. Look at the placement of the diamond inside the black protective cover. It is important to know the distance from the tip of the diamond to the opening in the protective cover for re-installation. 3. Loosen the 8/32 set screw of the black protective cover and remove the cover. 4. With one hand gently pull down on the indenter. 5. With the other hand rotate the turret to the next position and release the indenter. 6. Turn on the AC power and let the tester cycle. 7. Rotate the turret back to the indenter and take a test. If it is OK, re-install the protective cover. 8. Now check the alignment of the protective cover to the end of the indenter using the information that you have obtained from Step 2 above. Problems will occur if the gap from the end of the diamond to the opening in the protective cover is not correct. 9. Try another test to see if the cover is in the correct position. If there are problems you can make minor adjustments to the cover placement and re-test. If you can not make this adjustment remove the cover, call service 800-473-7838 and ask for a Field Service Rep to make a site visit.
My Tukon 2100 tester is not testing correctly
Stop the test by pressing the RETURN button. The previous message of Waiting to Contact Surface should be replaced by Ready for Ind or Meas. If it isn't, press the STAND BY key, wait for the screen to go blank then press the STAND BY key again. Next, check to see if the indenter is securely seated, the load cell is tight, and on the newer testers, the compliant member directly attached to the load cell should also be tight, then check to see if your specimen is in focus. Start the test, but watch closely to see if the indenter touches the specimen during its initial drop, it shouldn't. After the initial drop the indenter should move slowly to the specimen surface. During this movement the message of Waiting to Contact Surface should be displayed. Once the indenter contacts the surface the message is replaced with Testing MFA. If this is not happening reset the tester as mentioned above, select your lowest powered objective and try a test. If this works OK reset your Parfocality using the procedure in your Users Manual. If service is needed call 800-473-7838.
The display on my 2000 series tester has shut off after thirty minutes
Your tester has gone into "sleep mode". Press the power button on the user interface and the screen will illuminate. No, there is no way to disable the "sleep mode" feature.
What are my technical support coverages and options?
You have four options:
- Purchase a System Support Agreement. This provides you with priority in the call queue, remote access to our engineering staff, discounts and additional services for one full year.
- Sign-on to our Consultation Service line. This Fee based support provides you with priority in the call queue for those times that you just specific help.
- Limited Free Technical Support on a call back basis.
- Schedule a Field Service Engineer to visit your site.
What are Rockwell scale limitations?
At the low hardness end of a ball scale the ball may penetrate too deeply causing the cap to come into contact with a specimen which would damage the cap. In the case of a diamond indenter the sensitivity of the test diminishes as the diamond indenter penetrates further down the conical portion of the diamond. At the high end of the hardness scales, these limits result from the likelihood of fracturing or reducing the life of a diamond indenter such as testing carbide on C scale as opposed to the recommended A scale. A ball indenter is likely to have a flat spot as a result of testing above HRB95.
What are some of the reasons for incorrect hardness readings?
You should check the following:
- Replace wrong or damaged penetrators.
- Replace worn or damaged Anvil. Replace if necessary.
- Remove dirt and oil from under the anvil or penetrator.
- Change the rate at which the Major load being applied.
- Replace the test block with a new one.
What are the RS-232 settings for my tester?
500 Series To set up 2400 baud, the dip switches on the 500 Series Tester should be set as follows: Dip Switch 1 1 = On (Not Used) =0 2 = On (Not Used) =0 3 = On (Not Used) =0 4 = On (Not Used) =0 5 = On (Not Used) =0 6 = On (Word Length: Off=7 Char, On=8 Char)=0 7 = On (Off= Odd,On=Even)=0 8 = On (Parity: Off = Enable, On = None) =0 Dip Switch 2 (Baud Rate) 1 = On = 0 2 = Off =1 3 = On = 0 4 = Off =1 5 = Off = 1 6 = Off = 1 7 = Off= 1 8 = Off = 1 600 Series The tester is preset at: Baud = 2400 Parity = None Data Bits = 8 Stop Bit = 1 These settings are not adjustable. Series 2000 (Default Settings) Baud = 9600 Parity = None Data Bits = 8 Stop Bit = 1 Consult your Operator's Manual for instructions to change these settings.
What are the RS 232 settings for the U-Tronics 1024 printer?
500 And 600 Series Testers Dip SW Settings (located beneath the removable top cover of the printer on the right side of the circuit board.) 1 = On 2 = On 3 = Off 4 = On 5 = On 6 = Off These Settings Are For: Baud = 2400 Parity = None Data Bits = 8 Stop Bit = 1 Series 2000 For 9600 Baud set the dip switches as follows: (located beneath the removable top cover of the printer on the right side of the circuit board.) 1 = On 2 = Off 3 = Off 4 = On 5 = On 6 = On For 1200 Baud set the dip switches as follows: 1 = Off 2 = Off 3 = On 4 = On 5 = On 6 = On
What is a Knoop Indenter and what is it used for?
The Knoop indenter is an accurately ground diamond forming a rhombic based pyramid. An indent seen perpendicular to the specimen surface is rhombic in outline with diagonals having an approximate ratio of 7 to 1. Because of the Knoop indenter's geometry, indents of accurately measurable lengths are obtained with light loads. The depth of the indent is about 1/30th of the length of the long diagonal. Because of this it is well suited to testing very thin layers of plating case hardened steel, thin metal and foils, thin layers of decarburization and hard, brittle materials. The indenter is very sensitive to the flatness of the specimen's surface, the parallelism of the top and bottom surfaces, and especially to the degree of surface finish.
What is a Vickers identer and what is it used for?
The Vickers indenter ia a diamond ground to the shape of a square based pyramid with an angle of 136 degrees between faces. The depth of the indent it makes is about 1/7 of its diagonal length. The Vickers indenter penetrates about twice as far into the specimen as the Knoop indenter. Therefore, the Vickers test is less sensitive to surface conditions than the Knoop test. Because the indent is influenced less by the flatness and parallelism of the top and bottom specimen surfaces and their finish, it can be used on materials that are not suited for Knoop testing. However, because of the greater depth of the indent, the Vickers test is not as suitable for testing very thin foils and other materials as is the Knoop test. For equal loads, the Vickers indent (because of its shorter length) is more sensitive to errors in measuring the indent.
What is the depth of penetration for Regular Rockwell scales?
One Rockwell number represents a penetration of .002mm (0.000080 in.) Therefore, a reading of HRC 60 indicates a penetration from minor to major load of (100 - 60) X 0.002mm = 0.080 mm or 0.0032 in. A reading of HRB 80 indicates a penetration of (130 - 80) X 0.002 mm = 0.100 mm or 0.004in. Note: The numbers 100 and 130 above are the infinite hardness numbers for those scales.
What is the depth of penetration for Superficial Rockwell scales?
One Superficial Rockwell number represents a penetration of 0.001 mm or 0.000040 in. Therefore, a reading of 30N80 indicates a penetration from minor to major load of (100 - 80) X 0.001 = 0.020 mm or 0.0008 in. Note: The number 100 used in the calculation is the infinite hardness number used for all Superficial scales.
What is the difference between Micro and Macro indentation?
Micro indentation uses loads from 10grams to 1000grams. Macro indentation uses loads above 1000 grams.
What is the infinite hardness number for Regular Rockwell scales?
When using a diamond penetrator scales the infinite hardness number is 100. When using a ball penetrator scales the infinite hardness number is 130.
What is the infinite hardness number for Superficial Rockwell scales
The infinite hardness number is 100 for all Superficial hardness scales.
What Rockwell scale should I use if I do not know the hardness of a material?
HRA scale, which uses a diamond indenter with a 60kg weight is recommended. A diamond indenter is not likely damaged by penetrating too deeply into soft material, whereas a ball indenter may be flattened or damaged if the material is too hard.
Where can I find test blocks and manuals for my hardness machine?
Please contact Instron Sales at 800-695-4273.
Why are the readings on my test running a few points high?
Make sure you have the proper load selected. If you have too light of a load selected, the indent will be considerably shallow.
Why did my model 2000 stop during a test and prompt an error message?
The problem occurs when the specimen being tested is not properly aligned underneath the indenter. The force is applied to the specimen and the indenter moves down at an angle not perfectly perpendicular. When the error occurs, the operator cannot jog the indenter off the specimen. Perform the following procedure: 1. Scroll through the Menu Field list on the control panel to the CALIBRATE Menu and select Calibrate Depth. 2. Before the status menu states [Calibrating Depth], the operator will be able to press the Jog Up button and allow the force to be removed from the specimen. 3. After the indenter is cleared from the specimen it is recommend that the operator perform another depth calibration (consult your operator's manual).
Why might my display of an indent measurement not show correctly?
Most likely someone has accidentally set the Calibration switch on the rear panel of the Digital Filar box to the Read position. The switch MUST be set to OFF during testing and measuring.
Why might my test sample not generate a hardness value if it the same test was completed earlier?
Check the current weight selection on the tester, is it 500 grams or 1000grams? When you are reading an indent the load weight selector must be set to the same load that was used to create the indent because the digital filar box uses the load as part of the calculation.
Why won't my U-Tronics printer print on my Digital 500 Series tester?
The baud rate of the tester and the printer must be the same, Factory settings are :NO Parity,8 data bits, and Even Parity check. After verifying all switch settings are correct, the cable is connected between the printer and tester, turn on the printer and press the SEL button. You should have both the Red and the Green lights of the printer On. Next, turn on the tester and take a test. The printer MUST be turned ON and Ready prior to turning on the tester. If it still does not print, try running the Self Test feature for the printer by starting with the printer power ON, with the printer in the Offline mode. Offline mode means only the Red light is lit, so if the Green light is ON, press the SEL button to turn it Off. Next, press and hold the LF button,then press the SEL button while still pressing the LF button. The printer should start printing a self test pattern so you can release both buttons once it starts printing. To stop the printing, press the SEL button or you can wait until the printer times out. If self test works OK but the printer does not print under tester control call Service at 800-473-7838.