Tag: Ames rockwell hardness tester

Using Ames Testers in Hobby applications

Why Hobbyists Prefer Ames Testers

The Ames Portable Hardness Tester is a device used to measure the hardness of metals and alloys. While it is primarily used in industrial settings for quality control and material testing, there are also hobby applications for this tool. As we discussed in a previous blog, Ames portable testers are popular among knife makers.  Even the old testers are used because they are looking for a ballpark hardness in their trade.

Forging Martial Arts and Hunting Bladed Tools

hardness tester for lawnmower picture

The smithing forums tend to get mentions of Ames portable hardness testers as a reliable tool for the trade.  In the Blade Smiths Forum, ‘JenniferP’ ported about her Ames tester, stating it provides more accurate results than the Accu-test HRc tester.  Many members commented that they had old testers, but they are no longer eligible for calibration. Just a reminder, we may be able to repair and calibrate your old tester but without certification.  The reason for this is the fatigue on the frame makes the instrument unreliable.  It may leave our factory calibrated, but arrive to you not testing accurately.  While exact results are not always the goal of a Hobby Knifemaker, precision is a promise our company stands by.  Accuracy may be a critical point, especially for small thin pieces.  As mentioned on BladeMag, the correct hardness will guarantee superior strength in a blade.  The hardness test gives you an idea of the flex strength and confirms that the knife’s edge will hold.  Although many testers have been used by knife makers, testing with a Rockwell hardness tester provides the most reliable results.

In another forum for Hobby machinists, a member finds an old hardness tester and asks “How can this tool benefit my Hobby” to which other members answer, that this instrument is helpful for anyone heat-treating steel, and another member offers to take it off his hands.  Hobby applications in testing clutches for racing led to the development of a specific testing application which was developed outside of normal Ames tester capacity.  The Ames tester has value for any hobby application requiring a hardness test.

Some Examples of Hobbies that Ames Tester are Useful with:

  1. Metalworking: For hobbyists who enjoy working with metal, the Ames Portable Hardness Tester can be a useful tool for testing the hardness of different metals and alloys. This information can help guide decisions about which materials to use for specific projects, as well as provide a baseline for comparing the hardness of different materials.

  2. Jewelry making: In the world of jewelry making, the hardness of metals is an important factor in determining their durability and resistance to wear and tear. The Ames Portable Hardness Tester can be used to measure the hardness of different metals used in jewelry making, such as gold, silver, and platinum.

  3. Gunsmithing: For hobbyists who enjoy gunsmithing or working with firearms, the Ames Portable Hardness Tester can be a valuable tool for testing the hardness of gun parts and components. This information can help ensure that the parts are made from high-quality materials and are durable enough to withstand the rigors of use.

What is the Formula for Rockwell Hardness?

The formula for Rockwell hardness is as follows:

HR = N – (d / D)

HR = Rockwell hardness value N = total load applied to the indenter d = depth of penetration of the indenter D = diameter of the indenter

Where HR is the Rockwell hardness value, N is the load applied (in kgf), d is the depth of the indentation (in mm), and D is the diameter of the ball or the width of the diamond cone (in mm). The Rockwell hardness test uses different scales based on the load applied and the type of indenter used. The most common scales are the A, B, C, D, E, F, G, and H scales, each with a different combination of load and indenter. The Rockwell hardness test is widely used to measure the hardness of materials, including metals, plastics, and ceramics.

To apply the formula for Rockwell hardness, you will need to have the following information:

  • The load applied (in kgf)
  • The depth of the indentation (in mm)
  • The diameter of the ball or the width of the diamond cone (in mm)

Once you have this information, you can use the following steps to calculate the Rockwell hardness value:

  1. Determine the Rockwell scale: The Rockwell scale is determined by the load applied and the type of indenter used. For example, the Rockwell C scale uses a 150 kgf load and a diamond cone indenter.
  2. Measure the depth of the indentation: Use a microscope or other measuring device to measure the depth of the indentation made by the indenter.
  3. Calculate the Rockwell hardness value: Use the following formula to calculate the Rockwell hardness value:HR = N – (d / D)where HR is the Rockwell hardness value, N is the load applied (in kgf), d is the depth of the indentation (in mm), and D is the diameter of the ball or the width of the diamond cone (in mm).
  4. Interpret the results: The Rockwell hardness value can be compared to a standard chart to determine the hardness of the material being tested.

It is important to note that the Rockwell hardness test should be performed by a qualified technician using properly calibrated equipment. The test results may be affected by factors such as the surface finish of the material and the accuracy of the measuring equipment.

Which Hardness Test is Most Widely Used?

The Rockwell hardness test is one of the most widely used hardness tests in the United States. This is because it is relatively simple to perform, provides a quick and accurate measurement of hardness, and can be used to measure the hardness of a wide variety of materials, including metals, plastics, and ceramics. The Rockwell hardness test is also standardized by ASTM International, which provides guidelines for performing the test and interpreting the results.

The accuracy of portable hardness testers depends on several factors, such as the tester you are using, the material you are testing, the condition of the surface, and your skill and experience. In general, portable hardness testers provide accurate measurements, Ames Testers’ results are in the range of ±/-1 of the actual hardness value.

Some of the most commonly used portable hardness testers include the Leeb rebound hardness tester, the ultrasonic contact impedance (UCI) tester, and the portable Rockwell tester. These testers are designed to provide quick and non-destructive measurements of hardness, making them ideal for field use and on-site testing. Portable hardness testers can provide quick and repeatable hardness test results, making them suitable for many applications. Brinell and Vickers are also commonly used in the US, particularly in laboratory settings. However, the Rockwell test is generally considered more practical and versatile for industrial and field use due to its simplicity and ease of use.

Your choice of hardness testing method will vary depending on your specific industry or application. For example, you may prefer the Knoop hardness test for measuring the hardness of thin coatings or surface layers, while the Shore hardness test is commonly used if you are in the plastics and rubber industries. It’s important to note that portable hardness testers may not be as accurate as laboratory-based testers, such as the Brinell or Vickers hardness testers. These laboratory-based testers typically provide more precise measurements, but they are also more time-consuming and require more preparation and equipment.

The Brinell and Rockwell hardness tests are both widely used and accepted methods for measuring the hardness of materials. Each test has its own advantages and limitations, and the choice of test method depends on the specific application and the type of material being tested.

The Brinell hardness test is generally considered better for measuring the hardness of materials that have a coarse or inhomogeneous microstructure, such as cast metals, because it uses a relatively large indentation and a lower test load, resulting in a larger and more representative sample area. The Brinell test also has a wider range of test loads available, allowing for the measurement of a broader range of hardness values.

On the other hand, the Rockwell hardness test is often preferred for materials with a fine or homogeneous microstructure, such as steel, because it uses a smaller indentation and a higher test load, resulting in a smaller and more precise sample area. The Rockwell test is also faster and easier to perform than the Brinell test, making it more practical for industrial and field use.

Ultimately, the choice between the Brinell and Rockwell tests depends on the specific application and the type of material being tested. In many cases, both tests may be used in conjunction with each other to provide a more comprehensive analysis of the material’s hardness and properties.

The Importance of Hardness Testing in Machine Shops, Freight Yards, Warehouses, Factories and Laboratories

Hardness testing of metals before and after heat-treating is a common practice in manufacturing establishments like yours. Tests are made of materials before machining begins; of tools that are used and to check hardness after heat-treating.

Sheets of metals are tested to make certain they are not too hard to cause breakage of valuable dies. Bars are tested to insure proper machining speeds and protection of turning tools. Heat-treated parts are checked to control hardness within established limits for better performance and longer wear.

Ames Portable Hardness Testers are ideal for these purposes since they can be taken to the material receiving departments, to machines where you are working, and to every place by inspectors during the entire manufacturing process. Being portable, they check the hardness of parts while in machines being fabricated, and also after being assembled into complete sets.

Ames testers are used to check parts being machined that work harden under certain conditions. You test the hardness of large shear blades and cutters in machines, to check if heat developed in the operation of machines has affected the hardened shafts and parts. A book could be written on the many applications that Ames testers have found.

Customers all over the world learned to expect the best in design workmanship and accuracy in Ames hardness testers. With great pride, Ames offers portable hardness testers to all who make tests in Rockwell hardness scales. They are precisely made, carefully tested for accuracy, and beautifully finished. Enthusiastic owners, like you, have told others about Ames portable hardness testers and the savings made on a variety of interesting applications.

Until Ames Portable Hardness Testers were made in the year 1947, it was thought that only large bench-type hardness testers with weights and levers would give accurate results. Many attempts at building portable hardness testers were made by others that were failures, and the large bench machines seemed like the only accurate dependable type.

Ames employed the principle of the ordinary micrometer a C frame with a screw to perfect a lightweight, accurate easy-to-use hardness tester. Incorporating a sensitive dial indicator and graduated barrel dial, readings are taken directly in the Rockwell scales with no calculating or transposing. No skill is required by the operator, and the tests are made quickly and easily.

Ames portable hardness testers are used everywhere in a plant saving your company installation expenses, cost of transporting materials, and valuable stock that would be cut from bars and or sheets for test purposes with bench testers. Ames portable testers save you the cost of large stationary testers that would otherwise be needed in a plant. The cost of Ames testers is only a fraction of the bench-type testers.

The principle of Rockwell Hardness Testing is based on the scientifically established theory that a definite relationship exists between the hardness of a material and the depth of the penetration when the indentation method of measurement is used. The numbers of the Rockwell scales represent the depth of penetration when standard indenters are used under known pressure loads.

Frequently Used Rockwell Scales

This method has proved practical and accurate and is the simplest and quickest method yet devised for measuring hardness, hence the universal acceptance of Rockwell scales as a standard for measuring hardness. For testing hardened steels and alloys by the Rockwell method, a standard “C” penetrator is used under a pressure load of 150 kgs. The penetrator has a 120-degree cone carefully ground and polished and a diamond point that has been mechanically lapped to a spherical point with a .008-inch radius. For testing soft steels, nonferrous alloys, and cast iron, a standard 1/16″ diameter specially hardened steel ball penetrator, known as the “B” penetrator, is used and a pressure load of 100 kgs is applied. Readings in other Rockwell scales are obtained by using the diamond penetrator and ball penetrators of 1/8″ and 1/2″ diameter and 60 and 100 kg loads.

In the Rockwell method of Hardness testing, two loads, a minor, or initial load and a major load are applied. The depth of penetration actually measured is the additional depth resulting from the major load after the initial or minor load has been applied. This causes no serious difficulty or computation as the tester is set back to zero following the initial load. The resultant reading is believed to be a truer and more accurate measurement of hardness, in as much as surface imperfections or variations in the piece would cause inaccurate readings. By measuring only the increment or additional depth caused by the major load, inaccurate readings due to surface variations are eliminated.

In the Rockwell B and C scales, the minor load is 10 kgs and the major load is 100 and 150 kgs respectively. In the Rockwell Superficial scales, the minor load is 3 kgs and the major load is 15, 30, and 45 kgs respectively. Ames hardness testers employ the same penetrators and pressure loads as specified in Rockwell hardness testing and consequently read directly in the Rockwell scales. A chart of Rockwell scales is provided with each tester giving the penetrators and pressure loads to be used. This chart also gives equivalent Brinell readings.

What Comes with a New Ames Portable Hardness Tester?

A Look at the Ames Portable Hardness Tester Kit

The Ames Portable Hardness Tester case is made from high impact plastic, lined with foam to keep your Ames Portable Hardness Tester safe in transit.  There is a space for your Ames Portable Hardness Tester, 3 test blocks, penetrators and anvils in this case.  You may also choose to purchase one of Ames limited edition Model 1 testers in the original wood box.  This is a new tester in the old style box which was discontinued.

Of course your Ames kit will include the Ames Portable hardness Tester you have selected.  We manufacture Standard hardness testers which include the Model 1, Model 2, Model 1-4, Model 4-2, Model 4-4, Model 8 and Model 16 which test in Rockwell A, B, C, D and F scales, if you use them with our optional ball penetrators, they also test in Rockwell E, H, L, M, R, S and V scales as well. Our Superficial hardness testers include Model 1-S, Model 1-ST, Model 1-4S, and Model 4-2S which read in Rockwell scales N and T.  Using the additional ball penetrator they can also read in W, X and Y scales with the exception of the Model 1-ST which only reads in 15-T for tube testing. The only tester that does not include a carrying case is the model 16. 

Your kit will include a flat and a “V”anvil.  Anvils aid you in ensuring your tester provides valid readings.  The standard flat stock anvil is our most used anvil as it is designed for use with flat stock.  The “V” anvil is for small, round stock. Anvils are interchangeable.  We also sell raised flat anvils for thin stock, convex anvils for tube stock, round anvils for larger round stock.

You will receive one diamond penetrator and one ball penetrator in your Ames Portable Hardness Tester kit.  These penetrators are interchangeable.  You will need a different penetrator depending on the scale you are testing in.  Diamond penetrators are necessary for harder metals.  You can always purchase replacements on our website.

You will receive one hard steel, one soft steel and one brass test block with your Ames Portable Hardness Tester kit.  These testers help you with accuracy testing to ensure your tester is reading correctly.  Each Ames test block includes a certificate of calibration.  Superficial test blocks are standard with our superficial testers, and standard test blocks come with our standard hardness testers.  You may special order test blocks as well.

Ames hardness tester kits come standard with two extensions, one 1″ and one 1/2″ extension.  

Each Ames Portable Hardness tester includes a manual for use of your hardness tester.  If you lose your manual or need another copy, you can download it from our website at any time.  It is important to review this manual for proper care of your hardness tester, it also includes conversion charts for your use. 

Every Ames tester is factory calibrated before it is sold and every tester comes with a certification of calibration, our Ames test blocks include certification to the hardness on the test block.  Our testers meet NIST and ASTM E-110 standards.  You should return your tester to our factory for calibration once a year to ensure it continues to read accurately.  We also offer repair services.

Ames Announced the Model 8 Portable Hardness Tester in 1975

Ames introduced the model 8 hardness tester in February of 1975. This portable hardness tester has the capacity for either rounds or flats up to 8 inches to determine the hardness of metals and alloys in various Rockwell scales.

See the Model 8 Hardness Tester in Action!

The model 8 Ames portable Hardness Tester saves time and money by its ability to be taken to the workpiece being tested rather than having to cut pieces off to be taken to the laboratory for testing. The measuring head is independent of the measuring clamp or machine tool holder of your own design.

The model 8 Ames Portable Hardness Tester is accurate, light to carry, and easy to use. This tester meets the needs of both large and small plants. Use model 8 to test standard Rockwell scales, this tester is convienently is supplied with a carrying case.

With a frame depth of 4 inches, this tester reads Rockwell A, B, C, and other scales. The measuring head may be removed and mounted on a tool holder. This tester weighs 8.25 pounds.

Ames 4-4 portable hardness tester with manual

5 Benefits of using Ames Portable Rockwell Hardness Testers

Do you wonder if Ames portable hardness testers are the best option for you to use when testing the hardness of metal? Here are 5 reasons to choose Ames when you choose your hardness tester.

  1. Ames provides you with repeatable accuracy. Repetative tests on the material will give you in the same reading. You may not find this benefit generally available on competing hardness testers. You will experience no loss of accuracy when you transfer your readings into Rockwell scales. This is because all readings are made directly into Rockwell scales. Ames tester accuracy may be compared to the accuracy of bench-type testers when you perform tests in the smae enviornment.
  2. Ames hardness testers are simple for you to operate. Even unskilled users can learn to make accurate tests after a very limited period of practice. This means you do not need highly qualified inspectors to make hardness tests. This allows you to perform hardness testes more frequently, and provide your customers with maintenance and closer tolerances for their products.
  3. Portable testers can be taken anywhere. With hardness testers that are not confiened to the labratory you can perform hardness tests on material at the assembly line, in the receiving yard, or on material still assembled in the machine. You will avoid delays in production. You can also perform hardness tests in scenerios that are not accessable for use with bench style hardness testers.
  4. Test in Rockwell A, B, and C. Ames portable hardness testers allow you to test directly in regular Rockwell A, B and C scales, or in Rockwell Superficial N and T scales. You can simply change the penetrator and the major load and your tests can be made in Rockwell D, E, F, G, H, K, L, M, P, R, S and V scales. You can refer to the following conversion chart for Rockwell Hardness. Ames’ extensive line of portable hardness testers allows you to test material in a size range of 1mm to 1 meter in diameter.
5. Ames testers perform rapid tests. You can perform a single test in less than one minute. Ames portable hardness testers are faster to use than bench-type Rockwell testers. It is of particular value when numerous repetitive tests are required on the material.

Ames Model 16 Solves Super-Size Quality-Check Problems

The model 16 Ames Portable hardness tester is designed to allow you to test the hardness of materials up to 16 inches in diameter.  This tester has been referred to as a model 36 in the past because the chain is 36 inches long.  This name caused confusion so the tester has since been renamed the model 16.

Model 16’s chain clamp system and dual “V” anvils allow testing round items from zero to16 inches in diameter. For testing Rockwell A, B, C and other scales. This tester can be ordered in standard or superficial versions. The measuring head is independent of the clamp and may be removed for mounting on a holder of your own design. This tester weighs 8 pounds and conforms to ASTM standard E-110.

The Model 8 and Model 16 hardness testers are not available for purchase online due to the changing prices in the current market.  You can request a quote for either of these testers online.

The Model 8 is our Second Largest Tester:

Ames Upgraded their Wooden Instrument Case in 2000

What you get when you purchase an Ames Hardness Tester has never changed, the case you get your tester in did. From the time Electro Arc purchased Ames Portable Hardness Testers in 1975, they were sold as a kit including the tester, a set of hardness test specimens, diamond and ball penetrators, and flat and “V” anvils. Models larger than 1″ also include a set of jaw-opening adapters.

Ames portable hardness testers have a very traditional, fine-instrument look to them. They should: they have been around manufacturing and metal shops for fifty years, quietly doing their jobs. In their highly varnished, dovetail-joined wooden cases, some of them have probably been mistaken for antiques. Ames announced sleek new cases for its proven line of portable, easy-to-use hardness testers in May of 2000. The smart black bolded high impact cases, with full loam cradling provide better protection for these precision instruments than the wooden cases previously supplied.

Although they are precision instruments and should be handled as such, they are surprisingly durable. Some Ames testers are still working perfectly after thirty years of service, an age at which other machines really are antiques. Accuracy testing and annual calibration are required to keep these testers testing accurately. To help Ames owners get the most value from their investment, we offer both calibration and repair services for your Ames tester.

This kit contains everything you need to take your portable hardness tester with you in a secure and durable case. Ames portability lends itself to the appeal of using Ames portable hardness testers. Easy to use with one hand, easy to learn to use, and applicable in a number of work environments. Ames portable Rockwell testers have been manufactured continuously under the Ames name for over seventy years and for over fifty years under Electro Arc (now owned by Stillion Industries). They are guaranteed to comply with ASTM standard E-110 for testing hardness in Rockwell scales, with no conversion needed.

All Ames testers are 100% made in the USA, now 97% of the parts are machined by Stillion Industries. All Ames testers are assembled, tested, and calibrated onsite at our facility in Dexter, Michigan.

Measuring Hardness Rockwell Scale

Hardness Testing in Rockwell Scales

Hardness Testing – Rockwell scales

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. If you are using the Brinell scale check out our conversion chart.      

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. 

This Video Explains How to Use Your Rockwell-Brinell Conversion Chart: