Tag: rockwell testers

Rockwell Hardness Testers

Using Ames Testers in Hobby applications

Sep 21, 2023 by Carrin Harris 0 Comments , , , ,

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.

Rockwell Hardness Testers

What is the Formula for Rockwell Hardness?

Jul 11, 2023 by Carrin Harris 0 Comments , , , , ,

The Rockwell Metal Hardness Scales Explained

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.

Rockwell Hardness Testers

Which Hardness Test is Most Widely Used?

Jun 21, 2023 by Carrin Harris 0 Comments , , , ,

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.

Ames How To

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

Aug 22, 2022 by Carrin Harris 0 Comments , , , , , , , , , ,

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.

Download our Rockwell-Brinell Conversion Chart
Ames How To

Using your Ames Rockwell – Brinell Conversion table

Jul 15, 2022 by Carrin Harris 2 Comments , , , , , , ,
Please note the contact information in these charts is not up to date

Ames Portable Hardness testers read in the Rockwell scale. The Rockwell scale uses indentation and measures the depth of that indentation with a major and minor load to determine the hardness of a metal. The scale used depends of the metal being tested and the portable hardness tester used.

Ames developed a conversion chart for use in converting Rockwell scale readings into the Brinell scale. This allows you to easily determine the equal Brinnell reading. This conversion chart is broken down into categories to help you determine the converted value.

Hardened Steel and Hard Alloys, locate the type of penetrator you used and the scale you used in the top column for the scale. In this case you will only see C, A, D, 15N, 30N and 45N scales which can then be converted into the Brinell scale. Follow the appropriate line across to locate the corresponding reading in the middle column marked ‘Brinell’.

The next section is Soft Steel, non-ferrous metal, grey and malleable iron casting, this section covers the B, E, F, G, 15T, 30T and 45T scales. You will need to find the appropriate load in order to find the correct conversion. The bottom of this conversion chart includes corrections which cover any readings that were not included in the original chart.

The right-hand side of the chart gives you a guide to choosing the appropriate penetrator and hardness scale for your metal.

Download Ames’ Rockwell-Brinell Conversion Chart
Ames How To

6 Easy Steps to Testing Clutches with your Ames Portable Hardness Tester

Mar 18, 2022 by Ames Portable hardness testers 0 Comments , , , ,

Your Ames Portable Hardness Tester was designed for checking the hardness of materials in the Rockwell scales. This has become an asset to the racing industry which has developed a scale* for checking clutches using the Ames Portable Hardness Tester. The Ames tester helps to win races by providing repeatable results every time.

Featured in one of our promotions, Mike Bell, team II driver for Roy Hill Drag Racing, knows how important clutch plate survival is to victory in Pro Stock. Sudden heating can affect both surface and internal structure of clutch metals. Mike used Ames Rockwell Hardness Tester model 2 to check surface hardness of both plates before installation. He used the following recommended configuration. Roy Hill Drag Racing’s Ford Thunderbird set a Pro Stock National record of 6.73 seconds in 1995.

They provide the following recommendations for testing clutches* with your hardness tester in 6 easy steps:

To get yourself set up, make sure you have the following items: Model 2 Ames Portable Tester with a 1-inch anvil and 1/2 inch ball penetrator.

Step 1: Rotate the outer ring on the dial indicator and align the “dot” directly under the indicator needle. Position the clutch between the 1/2 inch ball penetrator and the 1-inch anvil. Make sure the surface is flat and the ball will not fall into holes or grooves.

Step 2: Rotate the handwheel clockwise until the needle on the gauge moves to the set position on the gauge face.

Step 3: Rotate the aluminum barrel counterclockwise so that the pin rests on top of the lucite magnifier

Step 4: Rotate the handwheel clockwise until the indicator needle reaches 60 on the indicator face.

Step 5: Immediately rotate the handwheel counterclockwise until the indicator is back at the set position.

Step 6: Read the black scale on the barrel. The thick line across the barrel is the whole number. (10, 20, 30, 40 etc.) The smaller hash marks on the left side of the barrel are in two-point increments.

Note: It has been established that using this method, test readings that fall between 65 to 80 give the best results.

You probably recognize former racing customers such as Massey Race Cars, Wayne County Speed, Stouts, Carl Smith, Glidden Racing, Ricky Smith Racing, Paul Rebeschi, Gary Brown Racing, Heck Racing, and Nickens Bros. Racing maintenance crews have come to rely on the results provided by Ames hardness testers.



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*Please note that this is a special testing method designed by professionals in the racing industry for use as described in these steps and does not represent recommended testing methods for our Ames Portable Hardness Testers.  In this case, the ball penetrator is used and the “B” scale is read.  The ball penetrator is not used to produce readings in the “B” scale.

Company News

Ames Upgraded their Wooden Instrument Case in 2000

Feb 1, 2022 by Ames Portable hardness testers 0 Comments , , , ,
Limited Edition model 1 Portable Hardness Tester in Vintage Wood Case

Limited Edition model 1 Portable Hardness Tester in Vintage Wood Case

Enjoy all of the perks of owning an Ames Model 1 Portable Hardness Tester with the Antique look of a wood case!  These limited edition Hardness testers are available while supplies last as a celebration for Electro Arc’s 75th Anniversary!

$3,447.29
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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.

Ames How To

Rockwell Hardness Charts for Metals

Dec 11, 2020 by Ames Portable hardness testers 0 Comments , , , ,

Ames Rockwell-Brinnell Conversion Chart

Our handy conversion chart helps you convert your Ames Hardness Readings from the Rockwell scales to Brinnell scales

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Choosing a Rockwell Hardness Scale

Below are a few Hardness Scale 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.

Do you need to convert Brinell to Rockwell?  See our Rockwell/Brinell conversion chart.

 

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.

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