Work Item
ASTM WK86726

Revision of A109/A109M-16(2018) Standard Specification for Steel, Strip, Carbon (0.25 Maximum Percent), Cold-Rolled


The proposed change relates to the hardness test used for very thin steel strip. ASTM A109 currently lists HR15TW scale for hardness measurement of steel strip with a thickness less than .025 in. [0.6 mm]. However, according to ASTM E18 standard, there are minimum valid thicknesses for each hardness reading in the HR15TW scale. Steel strip can be purchased with a thickness that is thinner than the thickness that would create a valid HR15TW scale reading. It is proposed that minimum thickness of 0.010 in. [0.25 mm] for HR15TW scale be added to the table as well as Vickers hardness readings per ASTM E92 for steel strip thinner than 0.010 in. [0.25 mm]. Negative votes associated with non-altered text will be considered not related and potential new business items.
Update: A published research paper was used to illuminate the minimum reasonable material thickness for use of the HR15TW scale. Note that use of the research data allows slightly thinner material than strict following of ASTM E18 guidelines for thickness. A read only copy of the technical paper can be accessed here:


Developed by Subcommittee: A01.19

Committee: A01

Staff Manager: W Scott Orthey

Work Item Status

Date Initiated: 06-08-2023

Technical Contact: Robert Puccia

Item: 000