Pace Technologies OMEGA SRT-15/150, Instruction Manual

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3601 E. 34th St. Tucson, AZ 85713 USA Tel. +1 520 - 882 - 6598 Fax +1 520 - 882 - 6599 email: pace@metallographic.com Web: http://www.metallographic.com
Please read this instruction manual carefully and follow all installation, operating and safety guidelines.
OMEGA SRT - 15/150 Dual Superficial /
Rockwell Hardness Tester
8.0 Hardness Testing Basic
Hardness Testing provides useful information, which can be correlated to tensile strength, wear
resistance, ductility, and other physical characteristics of the material. Hardness testing is therefore
useful for monitoring quality control and for aiding in the materials selection process.
ROCKWELL HARDNESS
Rockwell hardness (HR) is an indentation hardness test that is determined with a spheroconical
penetrator, or hard steel ball, that is forced into the specimen surface. The test is accomplished by
bringing the specimen into contact with the penetrator and allowing the penetrator to be slowly
forced into the specimen surface by a series of weights acting through a system of levers. After the
load is released, a dial pointer or LED screen indicates the hardness number.
Typical Applications:
- Quality control for metal heat treatment
- Materials receiving inspection
- Evaluation of welds in steels and other metal alloys
- Failure analysis
Standard Rockwell testing is at 60, 100 and 150 kg loads and Superficial Rockwell testing is at 15,
30 and 45 kg loads.
BRINELL HARDNESS
To determine a Brinell hardness number (BHN), a 10 mm diameter steel ball is typically used as an
indenter with a 3,000 kgf (29 kN) force. For softer materials, a smaller force is used; for harder
materials, a tungsten carbide ball is used. The BHN can also be converted into the ultimate tensile
strength (UTS), although the relationship is dependent on the material, and therefore is only an
empirically based value.
VICKERS HARDNESS
The Vickers test is often easier to use than other hardness tests since the required calculations are
independent of the size of the indenter, and the indenter can be used for all materials irrespective of
hardness. The Vickers test can be used for all metals and has one of the widest scales among
hardness tests. The unit of hardness given by the test is known as the Vickers Pyramid Number (HV)
or Diamond Pyramid Hardness (DPH).
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