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Portable Hardness Testers - Types Back
Portable Rockwell Hardness Testers
     Portable testers are needed when a Rockwell hardness test is specified on parts that do not readily lend themselves to testing on conventional "bench" testers, and when the cost of a "bench" tester cannot be justified.
     Typical applications for these instruments vary from machined steel parts to the extruded aluminum sections used in aircraft construction and tubes used for bicycle frames. 
     Both of the Rockwell testers listed in this guide provide direct, true Rockwell Readings without calculations or conversion tables.  The indentations made by these testers are of the correct shape and depth.

Portable Brinell Hardness Testers
     Portable Brinell hardness testers are most often used to test castings and forged materials that are too big for conventional testers.
     Typical applications for these testers include the testing of plate, pipe, pressure vessels, casting, rails, axles and other large or installed components. Brinell tests are required on materials with course grain structure which would cause inconsistent readings from a Rockwell tester. 
     Brinell testing is more tolerant of surface of surface roughness than any of the other hardness testing methods.

Portable Dynamic Hardness Testers
     Dynamic testers work by comparing the speed that an indentor strikes an object to its rebound velocity. The ratio of these values is a measurement of the material's hardness.  The instrument then converts the ratio to a conventional hardness value in Brinell, Rockwell B or C as selected. Conversions use generalized tables developed for many common materials and alloys.  This test method is covered by ASTM A956-96.
     Dynamic testers are popular due to their speed, convenience and ease of use.  They work best on heavy applications such as large and thick castings, forgings, axle shafts, rails, etc. Parts weighing less than 6 pounds and under 3/8" thick must be supported to get an accurate test.