Rockwell hardness values are expressed as a combination of a hardness number and a scale symbol representing the indenter and the minor and major loads. The hardness number is expressed by the symbol HR and the scale designation. UNITEDTEST hardness testers are based on the same construction principle of the COMP series which are already well known for their economic, reliability and easy using.

Principle:

1. The indenter moves down into position on the part surface
2. A minor load is applied and a zero reference position is established
3. The major load is applied for a specified time period (dwell time) beyond zero
4. The major load is released leaving the minor load applied

The resulting Rockwell number represents the difference in depth from the zero reference position as a result of the application of the major load.

Model:
HR-150A Rockwell Hardness Tester
HRM-45 Superficial Rockwell Hardness Tester

1), Economic, reliability and easy using;
2), The measuring device consists of a micrometer gauge with manual zero setting. The 108mm dial with either Rockwell standard or superficial scale (150-100-60Kgt) (15-30-45Kgt), allows direct reading of 1 unit and of 0.2 Rockwell units.
3), Manual testing process, no need for electric controlling;
4), It's steady and reliable for testing of curved surface.

Diamond Rockwell Indenter,
Diameter 1.5875mm Hard Alloy Steel Ball Indenter,
Large Testing Table,
Medium Testing Table and V-shaped Testing Table,
Weight (A, B, C),
HRC and HRB Hardness Blocks

ASTM E18 “Standard Test Methods for Rockwell Hardness of Metallic Materials”

ISO 6508 “Metallic materials — Rockwell hardness test”

ASTM D785 “Standard Test Method for Rockwell Hardness of Plastics and Electrical Insulating Materials”