ASTM E18 Rockwell Hardness


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APM Testing provides A2LA accredited services for Rockwell hardness testing at a fair price, with prompt delivery, and a detailed test report. Our laboratory also provides laboratory services for plastic testing, metal testing, rubber testing, oil testing, paint testing, plating testing, adhesive testing, circuit board testing, and other testing.

Purpose: Measure the Rockwell hardness of a metal sample per ASTM E18.

Sample: One block 1 x 1 x 0.050 inches (25 x 25 x 1 mm) or larger.
Smaller samples can sometimes be tested.

Price & Delivery: Contact us for a quote.

Basic Description: ASTM E18 is a method of determining hardness by measuring how deep an indenter pushes into a metal under a given load. There are multiple different Rockwell hardness scales with designations such as A, B, C, 30N, 30T, and more. Rockwell hardness readings can range from 20 to 100 with a higher number indicating a harder material. Rockwell B and C are the most common scales with B used for softer materials and C used for harder materials. The Rockwell B scale ends at a value of 100 which is roughly equal to the beginning of the Rockwell C scale at 20. Other scales are often used when the sample is too soft or thin to be measured by the B and C scales. Rockwell hardness is a good indication of the strength and wear resistance of a metal sample. Results are reported in a table as the average of 3 to 5 readings per sample.

Limitations: Samples must be prepared so that both the top and bottom surfaces are smooth or the results will not be accurate. Samples less than 0.050 inches (1 mm) thick are usually too thin for accurate measurements and may need to be measured by ASTM E384 Knoop Micro-Hardness. Readings may not be consistent for non-uniform materials such as cast irons which are commonly measured using ASTM E10 Brinell Hardness.


  • United Testing Systems, Tru-Blue II Rockwell Hardness Tester

Method Publisher:


  • Rockwell Hardness
  • Superficial Hardness
  • Hardness Testing

Related Techniques: