Category: Rockwell Hardness Testers

Ames Precision Model ST allows you to Check the Hardness of Tubing in Rockwell Scales

In May of 1977, Ames announced the release of the Ames Model ST portable Hardness Tester. This superficial tester is specifically designed for testing small diameter or thin wall tubing. The small anvil will fit into the inner wall of tubing as small as 3/16″ and is effective in checking larger sizes as well. The tube hardness tester reads in the 15-T scale and comes in a high-impact case just like our other portable hardness testers.

Original promotion for Ames Model ST – Tube Tester

The Ames model ST tubing tester uses a special cylindrical anvil to test soft tubular materials such as copper. This tester is recommended for small diameter tubing with thin walls. The maximum load for the model ST is 15 KG, anything greater will damage this tester.

Before you begin a hardness test using your model ST, be sure that the 1/16 ball penetrator is snuggly screwed into the end of the tester spindle shaft. The 1/18″ pin perpendicular to the spindle is the anvil.

How to use your Model ST Tube tester:

Step 1: Rotate the bezel (outer ring of the dial indicator) and position the face of the dial so that the dot on the face is directly below the indicator’s pointer hand.

Step 2: Position your part over the 1/8″ anvil and slowly rotate the handwheel until the penetrator makes contact with the part and moves the pointer hand on the dial indicator to the line marked set. Stop at this point. You have reached the minor load point (3 kg).

Step 3: Rotate the numbered aluminum barrel dial, so that the 1/16 inch pin rests on top of the lucite magnifier.

Step 4: Rotate the handwheel until the pointer hand on the dial indicator reaches the major load of 15 kg (do not over or undershoot the target). Immediately after reaching the major load, rotate the handwheel back to the “set” (minor load) position.

Step 5: To read the Rockwell hardness, find the fine line on the magnifier. The scale below the magnifier on the aluminum barrel is graded in units of 10. The short hash marks are in units of two.

Ames portable hardness testers collection

Benefits of Using a Hand Held Rockwell Hardness Tester

Hardness calculations on metals and a are important for the manufacturing of different things: from automobiles to electrodes. Hardness qulaity control is used in various fields like machine engineering, metallurgy, mining and energy resource extraction.

Metal hardness measurements are performed with the help of stationary or bench and portable hardness testers. The operating principle of stationary hardness testers on Rockwell scales are described in the standards on the corresponding methods. Hardness tests on stationary hardness testers are direct measurements. Consequently, hardness tests performed using these methods are more accurate than the measurements via indirect methods.

Hardness tests on portable hardness testers are indirect measurements. Most portable hardness testers use the ultrasonic contact impedance method. The result of measurements on portable hardness testers is recalculated into hardness values on the Rockwell scales. Usually portable hardness testers have the following error limits of hardness measurements: ± 2 HRC on Rockwell scales.

The following is why portable Rockwell hardness testers have an advantage. Portable hardness testers are significantly lighter, they can measure hardness directly on a manufactured detail and in hard-to-reach places. Portable hardness testers are the only hardness testers suitable for conducting measurements in the field. One portable hardness tester enables the user to obtain hardness values using at least three different methods. The cost of portable hardness testers is lower than that of stationary ones. Important characteristics of portable hardness testers are repeatability and reproducibility of measurements. Despite relatively modest accuracy in comparison with stationary hardness testers, portable units have high reproducibility and repeatability and can be successfully used for components screening, control of the product homogeneity on hardness, as well as measurements in the field

There are several other ways for hardness to be measured, but the Rockwell test is the easiest one to perform. The portable tester provides an accurate measurement that can then be converted to a number on the hardness scale. The device is also highly versatile, and metals of nearly any size and shape can be used

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The Rockwell Metal Hardness Scales Explained

You can use the Rockwell hardness test to test the hardness of materials. You will use the Rockwell test to perform tests on metals ranging from thin steel all the way to harder metals like Titanium. However, there are multiple scales to test in and these are identified by a letter ranging from A-V  Each scale uses a different indenter and load to perform the test.

When you perform a hardness test using the Rockewell scale, you can determine the hardness of metals and alloys of all kinds.  You will use a sphero-conical diamond penetrator or a hard steel penetratior which is forced into the part being tested with a predetermined pressure load and the readings represent the hardness numbers.

You can avoid errors in measurement due to surface imprefections or distortions at the periphery of the indentation with both minor and major loads.  The minor load of 10 KGS is applied first.  Remove the major load turning the handwheel back until the indicator hand is in position “set” on the dial.  The reading is taken from the barrel dial, which completes the whole operation in a few seconds.

The equation for the Rockwell hardness test for metals is below:  d=depth from zero load point.  N and s = various scale factors that can be found in the chart below.

Rockwell A scale

Used to test: Tungsten carbide.

Rockwell B Scale

Used to test: aluminum, brass, and softer steels

Rockwell C Scale

Used to test: harder steels.

There are other scales that are associated with a Rockwell superficial test. These scales use a lighter loads and shallow impressions to perform the test. These are used on testing very thin metals.

Ames Superficial Hardness Tester
Note: There is only one row of dial numbers for the Ames superficial tester.

Is your Ames Hardness tester genuine?

How to tell if your Tester is a Genuine Ames Hardness Tester

Ames began making Ames Portable Rockwell Hardness Testers in 1947.  In 1975 Ames was acquired by Electro Arc.  The Ames line of portable hardness testers has been made in Michigan since.

In 1997 it came to the attention of the Electro Arc company that each of it’s testers had been purchased by a company in China and duplicated.  Now Chinese copies of Ames Portable Hardness testers are available online, bearing a striking resembelance to the handcrafted testers we manufacture everyday.  Each of our testers are built one at a time following the ASTM E110 standard for the Rockwell scale.  Each genuine Ames Hardness tester is individually calibrated to the Rockwell scales and bears a signed certificate with each tester.

Is your Ames Hardness tester genuine?

How can you tell if your Ames Portable Hardness Tester is genuine?

  • It bears the Ames symbol within the dial indicator
  • You bought it directly from Amesportablehardnesstesters.com
  • Call us with the model number located on the front of your tester – we keep records of every tester we sell
  • Check the documentation included with your tester

How important is metal hardness testing? Consider the information provided by hardness testing and its significance in structural (i.e. bridges), aerospace, automotive, quality control, failure analysis and many other forms of manufacturing and industry. Determining material properties provides valuable insight to the durability, strength, flexibility and capabilities of a variety of component types from raw materials to finished goods.

Hardness testing is used extensively to characterize materials and to determine if they are suitable for their intended use. Why then would you buy a Chinese copy of a hardness tester?

  •  When quality is critical, should you trust a counterfeit hardness tester?
  •  Can it be calibrated?
  •  Will it hold up?
  •  Can it be serviced?
  •  Does it really meet the ASTM standard?

Ames Hardness Testers can be repaired and calibrated at our facility in Dexter Michigan.  We also service Dell models.  We do not offer service for any other brands.  When considering a purchase of a Rockwell Hardness Tester to insure quality, you should consider its quality, repeat-ability and reliability.

7 Things you Should and Should Not Do When Caring For Your Rockwell Tester

Your Ames portable hardness tester is a precious instrument.  As with any tool, proper care and maintenance is essential to maintain accurate testing results.  Remember, annual calibration is essential to properly maintaining your teseter.  Our metal hardness testers and accessories are machined, assembled and calibrated in our facility located in Dexter Michigan.

Ames Portable Hardness Testers are Made in Michigan

We have compiled the following list of do’s and don’ts to protect your hardness testing machine and keep it in the best working order.

7 Things You Should Do to Properly Care for your Ames Portable Tester:

  • Spray WD- 40 on a soft towel to clean your tester and test blocks
  • Make sure the Penetrator, extensions, and anvils are tightly secured
  • Store your test blocks in the plastic bag that is provided
  • Store your Rockwell tester in a safe location
  • Send your tester back for a yearly cleaning and re- calibration (if needed)
  • Only use the appropriate anvil for the application.
  • Perform regular tests on your Ames Tester to ensure accuracy
    Ames 4-4 portable hardness tester with manual

7 Things you Should Not Do to Your Ames Portable Tester:

  • Never apply oil directly on the tester
  • Do not drop or bang your tester
  • Never exceed major loads
  • Never use both sides of the test blocks. (one side only)
  • Do not retract the spindle past the threads of the penetrator
  • Never bang the tip of the diamond into the part or test block
  • Do not over or under shoot the minor or major loads

Your Ames Portable Hardness Tester is guaranteed to last for years if you follow these recommendations.  Be sure to follow the directions in the manual included with your tester.  Store your tester and testing blocks in the case provided when it is not in use.  As recommended by ASTM, perform regular accuracy checks to your tester to ensure the readings are accurate.

This blog was updated on December 14, 2021