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
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:
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.
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.
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.
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:
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.
Measure the depth of the indentation: Use a microscope or other measuring device to measure the depth of the indentation made by the indenter.
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).
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.
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.
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.
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.
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.
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 testers require 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.
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 blad hardness. There is a learning curve to using an Ames hardness tester, just like with any new measuring device. Yo 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.
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:
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 Scalesare 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 testalso 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.
Superficial testers are designed to test very soft and very thin materials and are designed to leave minimal surface distortion. The three reasons to choose an Ames Superficial hardness tester are, you are testing a very thin or soft material, standard superficial testers will destroy these materials or the test will show the hardness of the penetrator. This test will leave a less noticeable mark on the material you are testing. The superficial tester uses 15, 30, and 45 kg weight to measure rather than 60, 100, or 160 kg as with a standard hardness tester.
Use the Rockwell “N” scale to test Hardened steels, case hardened steels, and hardened strip steels down to about.006″ thick, and when you need to keep the mark left behind by the tester to a minimum. Use the Rockwell “T” scale to test soft steels, copper, and aluminum alloys. You can use an additional ball penetrator to test in Rockwell “W” for some hard thin material down to .006″ thick and cemented carbides. Rockwell “X” and “Y” scales are used for testing plastics. The model 1-ST is designed to test small-diameter and thin-walled tubes. Using Rockwell “15-T” to test tube materials like aluminum, thin steel, lead, iron, titanium, copper alloys, and cemented carbides.
Industries such as aerodynamics, steel plants, stamping manufacturers, electronics, appliances, and air conditioning part manufacturers use these superficial testers because their components are super soft and thin.
Superficial and standard hardness testers operate in the exact same way. The major difference is the material tested and the Rockwell scale you are testing in. You can purchase an Ames superficial tester in most of the same sizes as standard testers, with the exception of the model 8 and 16 testers, there is a like tester in the 4 main sizes of superficial testers:
Model 1-S and model 1 Ames testers are the same size. They have an opening 1 inch wide and a depth of 1 inch, so they are ideal for testing smaller parts.
The model 2 and 2-s are the same size and have an opening of 2 inches with a depth of 2.115 inches.
The model 1-4S and model 1-4 are the same sizes featuring an opening of 1 inch and a depth of 4 inches, great for longer, thin materials.
The model 4-4S and model 4-4 testers are the same size 4 inches wide and deep to allow you to test larger materials
The only tester with no standard equivalent is the model 1-ST, a special tube hardness tester.
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.