United Service Company Inc

The Rockwell hardness test method was developed right here in Hartford, Connecticut, by Stanley P. Rockwell around 1920.  While the testers of today look and function very differently from their earliest counterparts, the test method is still the same.  Using a penetrator and known weight load combination, which comprises a scale, the hardness of materials is determined by the depth of penetration.

Testers come in three variations:

• Standard - Applies loads of 150 kg, 100 kg and 60 kg.  Typically used to check HRC, HRA and HRBw Scales.

• Superficial - Applies loads of 15 kg, 30 kg and 45 kg.  Most common scales are HR15N, HR30N and HR15Tw.

• Twin - As the name implies, these testers are capable of checking all 30 Rockwell scales.