The Rockwell Hardness Tester model 900-331 is easy to operate and provides highly sensitive and accurate measurement results. Following the ASTM E-18 Rockwell standard, the 900-331 Rockwell Hardness Tester provides excellent repeatability in all standard Rockwell hardness measurements (see table below). This instrument is suitable for use in any environment, including: heat treatment equipment, tool magazines, workshops, and testing laboratories.
Direct reading from the dial
The design is professional and the operation is simple
The indication value is stable and the accuracy is high
The indication value is stable and the accuracy is high
Implements the American standard ASTM E-18
It is suitable for Rockwell hardness testing of cemented carbide, carbon steel, alloy steel, cast iron, non-ferrous metals and other materials.
Diamond indenters used in Rockwell C hardness
1.5875mm diameter steel ball indenter
3 Rockwell C standard hardness test blocks
1 Rockwell B standard hardness test block
1 Rockwell A standard hardness test block
150 mm diameter flat sample stage
63 mm diameter flat sample stage
Standard V-shaped stage
Accessory box
Dust cover
Blocks, indenters and block sets with NIST/ASTM calibration certificates
Implements the American standard ASTM E18-08B
| Hardness scale | Hardness Tester indenter type r | Initial test force N (kgf) | Total test force N (kgf) | Typical should |
| A | 120º diamond cone indenter | 98.07 (10) | 588.4 (60) | Tungsten carbide, thin steel workpieces and superficial hardened steel workpieces. |
| B | 1.5875mm diameter steel ball indenter | 98.07 (10) | 980.7 (100) | Copper alloys, softer steels, aluminum alloys, malleable cast iron, and more |
| C | 120º diamond cone indenter | 98.07 (10) | 1471 (150) | Steel, hard cast iron, pearlitic malleable cast iron, titanium alloys, deep surface hardened steel workpieces and other materials with a hardness of more than 100 HRB |
| D | 120º diamond cone indenter | 98.07 (10) | 980.7 (100 | Thin steel workpieces, medium surface hardened steel workpieces, pearlite malleable cast iron. |
| E | 3.175mm diameter steel ball indenter | 98.07 (10) | 980.7 (100 | Cast iron, aluminum-magnesium alloy, bearing alloy. |
| F | 1.5875mm diameter steel ball indenter | 98.07 (10) | 588.4 (60) | Annealed copper alloy, thin soft sheet metal |
| G | 1.5875mm diameter steel ball indenter | 98.07 (10) | 1471 (150) | Malleable cast iron, copper-nickel-zinc alloys and copper-nickel alloys. |
| H | 3.175mm diameter steel ball indenter | 98.07 (10) | 588.4 (60) | Aluminum, zinc, lead. |
| K | 3.175mm diameter steel ball indenter | 98.07 (10) | 1471 (150) | Bearing alloys, other very soft or thin materials. When using the smallest ball indenter and the heaviest force measurement, the other side of the test piece penetrates the indentation, which is why these hardness systems should be considered to measure the hardness of the material |
| L | 6.35mm diameter steel ball indenter | 98.07 (10) | 588.4 (60) | |
| M | 6.35mm diameter steel ball indenter | 98.07 (10) | 980.7 (100) | |
| P | 6.35mm diameter steel ball indenter | 98.07 (10) | 1471 (150) | |
| R | 12.7mm diameter steel ball indenter | 98.07 (10) | 588.4 (60) | |
| S | 12.7mm diameter steel ball indenter | 98.07 (10) | 980.7 (100) | |
| V | 12.7mm diameter steel ball indenter | 98.07 (10) | 1471 (150) |