All posts by Carrin Harris

Rockwell Hardness Testers

Using Ames Testers in Hobby applications

Sep 21, 2023 by Carrin Harris 0 Comments #Ames portable hardness tester, #Ames portable hardness testing, #Ames rockwell hardness tester, #Ames tester, #rockwell testers

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 onBladeMag, 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.

Ames How To

Testing Tin Plate with an Ames Portable Superficial Tester

Aug 19, 2023 by Carrin Harris 0 Comments #Ames superficial tester, #test hardness tin, #test tin hardness, #testing tin, #tin hardness

The object of hardness testing tin plate is to determine the Temper (hardness) designation of the material. This is a classification system where the temper designation indicates the appropriate use for your tin plate. Tin plate has different and specific characteristics at each designation. The higher the temper designation, the harder the material.

You can test tin plate in either the Rockwell 15-T scale (R15T) or in the Rockwell 30-T scale (R30T) and you will always use a diamond spot anvil. The diamond spot anvil is used to avoid the “anvil effect” which is when the result of the test is affected by the steel anvil because the thinness of the material being tested did not support the major load pressure. In other words, the hardness of the anvil was tested rather than the material. The Diamond Spot Anvil is too hard to yield to the major load and, therefore, will not influence the test results. The selection of scale is determined by the thickness (or weight) of the material to be tested. The thickness of the tin plate is designated as a weight. Tests in R15T are made on plate which is less than 75 lbs. per base box. Tests in the R30T are made on plate which is over 75 lbs. per base box.

Since the standard used by the U.S. Tin Can Industry is the R30T scale, all R15T test results must be converted to R30T. For conversion and determination of Temper Designations with related characteristics, we offer the following chart:

Temper Tin Plate
Designation R30T R15T Characteristic

   T-1        52 maximum      78.5 maximum        soft for drawing

   T-2        50 to 56        77 to 80        moderate drawing
                                Where some stiffness 
                                is required

   T-3        54 to 60        79 to 81.5      shallow drawing

   T-4        58 to 64        81 to 85        general purpose
                                Where increased 
                                stiffness is required

   T-5        62 to 68        82.5 to 85.5        stiff, rephosphorized 
                                Steel used for 
                                Hardness to resist 
                                Buckling

   T-6        67 to 73        85 to 88        rephosphorized steel
                                for great stiffness

Tinplate is a popular material used in the packaging industry due to its excellent corrosion resistance and durability. However, the mechanical properties of tinplate can vary depending on the manufacturing process and the thickness of the coating. Therefore, it is essential to conduct hardness testing to ensure that the material meets the required specifications.  Hardness testing is a non-destructive method that measures the resistance of a material to deformation. The Ames Portable Hardness Tester is a useful tool for testing the hardness of tinplate.

What is an Ames Portable Hardness Tester? The Ames Portable Hardness Tester is a handheld device that uses the Rockwell hardness testing method to measure the hardness of a material. The tester consists of a spring-loaded diamond-tipped indenter that is pressed into the surface of the material under a specified load. The depth of the penetration is measured, and a hardness value is calculated based on the amount of penetration. The Ames Portable Hardness Tester is easy to use and can provide accurate and repeatable results.

How to Test Tinplate with an Ames Portable Hardness Tester: Before conducting a hardness test on tinplate with an Ames Portable Hardness Tester, it is essential to ensure that the surface of the material is clean and free of any contaminants. The test should be conducted on a flat surface of the tinplate that is at least ten times thicker than the depth of the indentation. The test should be conducted using the C-scale, which is the most common scale used for testing tinplate.

To conduct the test, the Ames Portable Hardness Tester is placed on the surface of the tinplate, and the load is applied by turning the knob on the device. The load should be applied slowly and evenly to ensure accurate results. After the load has been applied, the indenter is removed, and the depth of the penetration is measured. The hardness value is then calculated using the following formula:

Hardness = 100 – (Depth of penetration x 2)

The hardness value can then be compared to the required specifications to determine if the material meets the necessary hardness requirements The Ames Portable Hardness Tester is easy to use and can provide accurate and repeatable results. By conducting hardness testing with an Ames Portable Hardness Tester, manufacturers can ensure that their tinplate meets the necessary hardness requirements and is suitable for use in a wide range of applications.

Rockwell Hardness Testers

What is the Formula for Rockwell Hardness?

Jul 11, 2023 by Carrin Harris 0 Comments #Ames rockwell hardness tester, #measuring rockwell hardness, #rockwell hardness, #rockwell hardness formula, #rockwell scales, #rockwell testers
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 #Ames, #Ames portable hardness tester, #Ames rockwell hardness tester, #rockwell scales, #rockwell testers

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.

Rockwell Hardness Testers

When to Choose an Ames Superficial Hardness Tester

May 21, 2023 by Carrin Harris 0 Comments #Ames, #Ames superficial hardness tester, #superficial hardness tester

There are two types of Rockwell testing:

Standard Rockwell: the minor load is 10 kilograms of force (kgf) and the major load is 60, 100 or 150 kg.

Superficial Rockwell: the minor load is 3 kg and the major load is 15, 30, or 45 kg.

In conducting both tests, you nay use either a diamond cone or steel ball indenter, depending on the characteristics of the material you are testing. Today you will learn more about why you would need superficial Rockwell hardness testing.

The Superficial Rockwell Scales:

Are you wondering when to purchase a superficial hardness tester rather than the standard one?  Rockwell superficial scales are used to test materials too thin or small for the regular scales or outside the regular ranges. Generally, Diamond Indenters are used for hard materials while Ball Indenters are used for soft materials. The HR 15 N scale is useful for testing hard thermal spray coatings like ceramics and carbides, while at the other extreme the HR 15 Y scale is used to test very soft abradable coatings Superficial hardness testers can be used for testing shallow areas that you would normally use a standard hardness tester for.  

Use a superficial tester when you are testing super thin material that would be damaged by a standard tester’s penetrator, for example, case-hardened steel and shim stock.  Battery cases are another example, plastics can also be tested with a superficial hardness tester.   The video below gives you a comparison of thin materials and Ames superficial testers you can choose from to conduct a superficial hardness test.

Use Superficial Hardness Testers to Test Thin Materials:

Our special superficial tester is the model 1-ST, this tester allows you to test the hardness of tubes.  Tube testing is possible with either standard or superficial hardness testers but the model 1-ST allows you to test very small diameter tubes that are too large to test with the other testers.

Superficial Portable Rockwell Testers

Ames Model 1-S Superficial Portable

Metal Portable Rockwell Hardness Testers For Sale Includes: High impact case Diamond Penetrator – Serialized and Traceable - Part Number

Superficial Portable Rockwell Testers

Ames Portable superficial Hardness Tester

Portable Metal Rockwell Hardness Tester For Sale Includes: High impact case Diamond Penetrator – Serialized and Traceable - Part Number

Superficial Portable Rockwell Testers

Ames Superficial Portable Hardness Tester

Rockwell Hardness Testers For Sale Includes: High impact case Diamond Penetrator – Serialized and Traceable - Part Number T-1131 1/16

Superficial Portable Rockwell Testers

Ames Portable Superficial Hardness Tester

Includes: High impact case Ball Penetrator – Serialized and Traceable 1/16 Ball Penetrator – Serialized and Traceable - 1/16" Ball

Superficial Portable Rockwell Testers

Ames Model 4-2S Portable Hardness

Ames Portable Metal Hardness Testers Includes: High impact case Diamond Penetrator - Serialized and Traceable - Part Number T-1131 1/16"

Rockwell Hardness Testers

Why Quality departments purchase Ames Testers

Apr 21, 2023 by Carrin Harris 0 Comments #Ames, #Ames portable hardness tester, #Ames portable tester, #Ames tester

Quality departments like yours depend on the precision of Ames portable testers. Ames testers are manufactured to follow the ASTM E-110 guidelines. These testers are lightweight and easy to use anywhere. You can count on the accuracy of readings within +/- 1 Rockwell point. Your penetrators, anvils, and test blocks are serialized and traceable to the NIST Standards. You can test inner diameter as well as outer diameter surfaces. This is made possible with our interchangeable penetrators and anvils. Ames testers provide you with the accuracy and repeatability you need. Depend on this instrument to provide you with quick results in every application.

New Tester Kits Contain Everything you Need

When you purchase a new tester, the Ames kit has all the accessories you need to use your tester. You will receive, one diamond and one 1/16” ball Penetrator, extensions, and one each flat and V anvils. Three test blocks are included so you can conduct regular accuracy checks with your tester. This kit is contained in a high-impact carrying case. You also receive the operator’s manual, and certificates of traceability.

Rockwell Scales provide Easy to Read Results

With the standard tester kit, you will be able to test the following Rockwell scales: A, B, C, D, F, G. With 1/8”, ¼”, and the ½” ball penetrators. You can use the same tester to test in the Rockwell scales; E, H, K, L, M, P, R, S, and V. All test results are read directly from the tester with no charts or conversion tables needed. You may also want to consider purchasing a bench stand with your Ames tester, this enables you to use both hands while testing material hardness.

Superficial Testers Allow you to Test Very Thin Materials

Ames superficial testers follow the same ASTM E-110 guidelines as our standard testers. With the lighter minor loads, the tester is able to read shallow case hardened parts, hard thin materials, cemented carbides, and plastics. This tester reads in Rockwell scales N, T, W, X, and Y. Take readings on materials as thin as .006″ with the superficial tester without damaging the material. Superficial testers leave a much smaller indent than the standard testers.

Uncategorized

Choose Rockwell Hardness Test Blocks for your Ames Tester

Apr 18, 2023 by Carrin Harris 0 Comments

Ames test blocks assist you in maintaining the accuracy of your hardness tester and are a necessary tool for setting up your hardness tester for new hardness testing jobs. You can purchase Ames test blocks online for your standard or superficial hardness tester in hard steel, soft steel, and bronze. You can also special order test blocks for your specific hardness testing needs.

Common Questions About Test Blocks

What is a hardness test block?

A hardness test block is a standardized reference piece used in the testing of the hardness of metals and other materials. These blocks are made from materials with a known and consistent hardness and are used to calibrate or verify the accuracy of hardness testing equipment.

Hardness test blocks come in various shapes and sizes depending on the type of hardness test being performed, and they are usually made from materials such as steel, tungsten carbide, or aluminum. The blocks are often given a unique identification number or marking, which corresponds to a specific hardness value or range, and this information is used to ensure that the testing equipment is providing accurate results.

The use of hardness test blocks is important in maintaining the accuracy of hardness testing, as it allows for equipment to be calibrated and verified on a regular basis to ensure that it is providing consistent and reliable results.

What are hardness test blocks made of?

Hardness test blocks are made from materials with a known and consistent hardness that can be used as a reference point for hardness testing. The material used for the block will depend on the type of hardness test being performed and the range of hardness values that need to be measured.

Some of the most common materials used for hardness test blocks include:

  1. Steel: Steel is a common material for hardness test blocks and is often used for Rockwell hardness testing. The blocks can be made from a range of different steel alloys, such as SAE 4130, which has a known hardness value and is used as a standard reference material.
  2. Tungsten Carbide: Tungsten carbide is a very hard and wear-resistant material that is used for hardness testing blocks in a range of applications, including Vickers and Brinell testing.
  3. Aluminum: Aluminum is a softer metal than steel or tungsten carbide but can still be used for hardness testing blocks. It is often used for testing the hardness of softer metals, such as copper or brass.
  4. Copper: Copper is another softer metal that can be used for hardness testing blocks. It is often used for testing the hardness of very soft materials, such as lead or plastic.

The specific material used for a hardness test block will depend on the type of test being performed and the desired range of hardness values. The blocks are often given a unique identification number or marking, which corresponds to a specific hardness value or range, and this information is used to ensure that the testing equipment is providing accurate results.

What is the purpose of a block test?

The purpose of a test block, also known as a calibration block or reference block, is to calibrate or verify the accuracy of a non-destructive testing (NDT) equipment or inspection system. These blocks are made from materials with known properties and characteristics that are similar to the materials being tested in order to establish a baseline for comparison.

Test blocks are used in various NDT methods, such as ultrasonic testing, eddy current testing, and radiographic testing. By using a test block, an inspector or technician can determine if the NDT equipment is operating properly and producing accurate and reliable results.

The test block is scanned or inspected in the same way as the actual part or material being tested, and the results are compared to the known properties of the test block to ensure that the equipment is functioning correctly. If there are any discrepancies between the results obtained and the known properties of the test block, the equipment may need to be adjusted or calibrated before it can be used for actual testing of materials.

What is harder Rockwell B or C?

Rockwell B and Rockwell C are two scales within the Rockwell hardness testing system, which measures the hardness of a material by measuring the depth of an indentation made by an indenter under a specific load.

The Rockwell C scale is generally used for harder materials, such as hardened steels, whereas the Rockwell B scale is used for softer materials, such as brass, aluminum, and mild steel.

In general, the Rockwell C scale is harder than the Rockwell B scale. This is because the Rockwell C scale uses a harder diamond indenter and a heavier load than the Rockwell B scale, which results in a deeper indentation and a higher hardness reading.

For example, a typical Rockwell C scale hardness range for steel is around 20 to 70 HRC, while a typical Rockwell B scale hardness range for steel is around 30 to 100 HRB. Therefore, if two materials have the same Rockwell hardness value, the material measured on the Rockwell C scale would generally be considered harder than the material measured on the Rockwell B scale.

What is the material used in Rockwell hardness tests?

Rockwell hardness testing is a method used to measure the hardness of metals and other materials, and it involves making an indentation in the material with a specified load using a diamond or tungsten carbide indenter. The material used for the Rockwell hardness test is the material being tested itself.

The Rockwell hardness test can be performed on a wide range of metallic and non-metallic materials, including steel, aluminum, copper, brass, plastics, and ceramics. The material being tested must be prepared to a certain standard, such as a flat surface and a specific thickness, to ensure accurate and consistent results.

What is the price of hardness test blocks?

The price of a hardness test block can vary depending on several factors such as the material of the block, the size of the block, the range of hardness values, and the manufacturer or supplier.

Generally, hardness test blocks can range from a few hundred dollars to several thousand dollars, with some highly specialized blocks costing even more. Steel blocks are typically less expensive, with prices ranging from $100 to $500, while tungsten carbide blocks can cost upwards of $1000 or more.

It is important to note that while the cost of a hardness test block may seem high, it is a crucial part of any hardness testing program and is necessary for ensuring accurate and reliable hardness testing results. Investing in a quality hardness test block can save time and money in the long run by reducing the need for re-testing and ensuring that the equipment is properly calibrated.

Rockwell Hardness Testers

Why Hardness Matters When Choosing Drill Bits

Mar 21, 2023 by Carrin Harris 0 Comments #Ames, #Ames tester, #drill bit hardness, #drill hardness, #testing drill bit hardness, #testing drill hardness

Knifemakers and Saw manufacturers are among the long-term customers of Ames Portable Hardness Testers. This makes sense because the hardness of your cutting instrument is an essential part of marketing your product. Drill bits are no different. The hardness of your drill bit tells a lot about the length of time you can count on the cutting power of your drill. One local manufacturer of drill bits compares the hardness of cobalt and carbide drill bits. This comparison references Rockwell hardness, showing that the hardness test provided the necessary information for customers like you considering purchasing drill bits.

Carbide Drill bit, disintegrated carbide drill bit

What is the Hardness of your drill Bit?

According to the Tech talk carbide drill bits are of 75 HRC while cobalt drill bits are only 65 HRC. This makes the difference when using the drill bit because they last longer, are more heat resistant, and can improve your cycle times. On the flip side, carbide drill bits are more expensive, are harder to resharpen, and may need to be replaced when it is blunt.

Removing broken drill bits is no fun. Electro Arc metal disintegrator owners have experience with removing both cobalt and carbide drill bits. You may have experienced delays in manufacturing and machine downtime, due to a broken drill bit stuck in an essential part. Knowing your drill hardness can help you avoid this situation.

What is the Role of Hardness in Removing broken Drill Bits?

You can use Ames portable hardness testers to test hardness in just minutes. These testers are convenient because they can be used in tight spaces, like on the production floor to ensure your parts are the correct hardness. You can also plan to remove broken drill bits when you need to by having the correct machine on hand to do so. Cobalt and carbide drill bits, knives, and saw blades all have different hardnesses, so they will be different to remove. Our AC machines can remove your high-speed steel but you will need a DC machine to remove broken carbide drill bits.

As you know, there are lots of ways to check material for hardness, the most recognized is Rockwell. A wide assortment of portable testers are available on the market. Most of them can be converted to some sort of varying Rockwell reading. Electro Arc Ames portable hardness tester has been recognized across industries as a reliable, easy-to-use, accurate tester.

Some portable testersrequire manpower to hold the tester perfectly aligned and with enough force to get a consistent reading. Most of these testers use a spring-loaded penetrator shaft. This is fine but, if conditions are not correct, (misalignment, clamping pressure, surface finish, or material density), the test will be inaccurate and repeatability will be nonexistent. Ames Portable Hardness Testers, require no electricity and have a zero carbon footprint. The sling shot configuration securely traps the specimen between the penetrator and anvil allowing positive contact for the minor and major loads to be applied.

Rockwell Hardness Testers

Hardness Testing for Knife Makers

Jan 21, 2023 by Carrin Harris 0 Comments #portable hardness tester, #portable tester, #test blade hardness, #test knife hardness, #test metal hardness, #test saw hardness

Whether you are a hobby saw or knife maker, you may be wondering if you can use an old Rockwell hardness tester to test the hardness of your blades.  Many forums are full of comments from people just like you who have found old hardness testers at garage sales and want to know how to use them to verify their bald hardness.  There is a learning curve to using an Ames hardness tester, just like with any new measuring device. You can download the user manual for Ames testers for free and you will find all of the conversion charts you need to accurate reading no matter what you are testing.

Download the Ames Manual
Go to the Hardness Charts

Check out this in depth Demo of an Ames Hardness Tester from an Advanced Knife Maker:

As a knife maker, you may have used a hardness tester to perform hardness tests on your knives or saw blades.  Ames portable hardness testers are a preferred model for blade makers to perform quick hardness tests.  Many knife makers may not have the budget to purchase a new Ames Portable Hardness Tester.  Used testers available on eBay and Facebook marketplace can be appealing because of their discounted price.  It is important to check the serial number of a used hardness tester before you purchase it.  Old hardness testers may serve the purpose you are looking for: A basic hardness test.  However, it is important to know that you may not be able to have the tester certified when it is repaired if it is too old.

The frames of old hardness testers can fatigue, which will not allow the tester to perform an accurate hardness test, even with calibration you may find that the hardness readings don’t stay accurate.  This is why we recommend you look for hardness testers that have a serial number of 12000 or newer.  You should always turn the tester over and check the sticker on the back.  Every Ames factory-calibrated tester has a sticker telling you when the next calibration should be performed.  Another way to determine if your used tester is a good buy is to perform accuracy testing.  You can use the test blocks provided with the tester to make sure the readings are accurate.  Make sure you are using the correct penetrator for the scale you are reading in.

Grismo Knives demonstrates Testing Blade Hardness with Ames Testers:

Rockwell Hardness Testers

Are Durometers the same as Hardness Testers?

Nov 23, 2022 by Carrin Harris 0 Comments #ames hardness tester, #durometer, #hardness tester, #rockwell scale

Durometers are designed to be used with plastics while hardness testers can be used to test the hardness of most materials

Hardness testers may also be referred to as durometers. The main difference between these two instruments is the materials being tested. Durometers, generally test soft materials, while hardness testers are designed specifically to test the surface hardness of materials ranging from plastics to metals like steel. Some testers have been modeled and branded for their hardness testing scales. Hardness testers may be large and stay in a fixed location – bench testers, other testers are designed for portable use such as the Ames portable hardness tester. In 1812 Friedrich Mohs developed a scale to identify the hardness of minerals, ranking them on a scale of 1-10. The Mohs hardness scale has identified minerals’ hardness and known objects that minerals can be tested against to determine the hardness. This is the oldest known hardness measurement system.

The Shore Scales are used in testing the hardness of plastics – Consisting of Shore 00 for super soft materials like gum through Shore D for hard plastics and rubbers. The scale was designed by Albert Ferdinand Shore in 1920 although his tester was not the first device to be called a durometer. The Shore durometer was designed specifically to test polymers, elastomers, and rubbers. The shore scales provide a universal reference for a large scale of non-metal hardness testing.

The Scleroscope hardness tester was developed in the same time period as Brinell by Albert Shore of Shore Instrument Manufacturing Company, this instrument did not use traditional penetrators, but a scale to measure the material’s elasticity, this instrument was replaced by more accurate and efficient forms of testing as technology advanced.

Vickers durometer This use of the durometer refers to the hardness test, not the instrument. This scale is popular in the UK and Europe and is one of the widest scales for hardness testing. The Vickers hardness test also referred to as the microhardness test procedure was developed in 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials from ceramics to metals.  HBW (H from hardness, B from Brinell, and W from the material of the indenter, tungsten (wolfram) carbide). In former standards HB or HBS were used to refer to measurements made with steel indenters. The Vickers test uses a smaller indenter making it easier to use on materials like foil and other very thin materials. Also, the required calculations are independent of the size of the indenter, making calculations easier. The basic principle, observes a material’s ability to resist plastic deformation from standard sources. The Vickers test can be used for all metals and has one of the widest scales among hardness tests. The unit of hardness given by the test is known as the Vickers Pyramid Number (HV) or Diamond Pyramid Hardness (DPH). The hardness number is determined using the load over the surface area of the indentation, not the area normal to the force, so it is not actually pressure. The hardness number can be converted into units of pascals, but should not be confused with pressure, which uses the same units.

The UCI (Ultrasonic Contact Impedance or Portable Vickers Procedure) hardness test is newer, developed in 1968 by Claus Kleesattel. This portable testing method uses the Vickers hardness test method described above which requires the use of a diamond indenter according to ASTM standards.

This method uses a 136-degree diamond at the end of a vibrating rod. The rod is depressed into a fixed surface and a fixed load is applied, the ultrasonic vibration frequency is then measured and calculated into a hardness value. This hardness testing procedure is used for measuring the hardness of small items, objects with a wall as thin as 1 mm, can be used to test hardness on complex forms, and measures the hardness of surface hardened layers. The indentation is considered less destructive than other testers making this a popular option.

The Knoop method is an alternative to the Vickers technique. Developed by Fredrick Knoop at the National Bureau of standards (now known as NIST) in 1939. Primarily used for thin materials with the risk of cracking like ceramic and in cases where a thin layer like a coating needs to be tested. This microhardness testing method uses a narrow diamond-shaped indenter. Knoop is the preferred method for small long test specimens whereas the Vickers method is more effective on small round pieces. The Knoop method is time-consuming and requires preparation of the test piece. Readings can be impacted by load, temperature, and environment as well.

The Brinell hardness test is the oldest hardness test, developed by Sweetish engineer, Johan Brinell. this hardness testing method can be used on rough materials and is performed in a standard or non-standard method. Irregular surfaces do not impact the outcome of this hardness test and can be used to test the hardness of components made from powder and cast. This scale can be used to test both soft and hard materials hardness such as tin, steel, and iron. Some restrictions of this method include, it can not be used on smaller objects, it creates a deep impression and the test can only be performed on a flat surface. This method is also time-consuming and has a higher rate of error in conducting measurements. A variety of hardness testers are available on the market providing Brinell hardness tests.

A popular standard in the hardness testing industry is the Rockwell scale. Developed by Stanley Rockwell in the early 1900s, the scale uses the indentation of a smaller steel ball than the Brinell method (less than 4mm) or a diamond cone to create and measure penetration and determine hardness. This test can be performed quickly. No preparation is required on the material, the scale is easy to read and requires no extra equipment which makes it the most commonly used hardness testing method. You can test the hardness of soft and hard metals in the Rockwell scales, the portable testers allow onsite testing quickly and easily. The Rockwell hardness test is standard on a variety of testers, bench top models were developed by Stanley Rockwell and developed by the Wilson-Mauelen company, acquired by Instron corporation in 1993. The Ames portable hardness tester was developed in 1947 and sold by Ames Precision in Massachusetts until Electro Arc purchased the product line in 1975. These Rockwell hardness testers provide portable hardness readings in the Rockwell scale, and a conversion chart into the Brinell scale.