This standard specifies the method for Rockwell superficial hardness test (scales and hardness range according to Table 1 for metallic materials ).
TABLE 1 HARDNESS RANGE
( Clauses 1, 2.1 and 4.1 )
Hardness Scale Hardness Symbol Type of Indenter Preliminary Test Force, Fo N (kgf) Additional Test Force, Fl N ( kgf) Total Test Force, F N (kgf) Hardness Range
15N HR15N Diamond cone 29·42 (3) 117·7(12) 147·1(15) 70·94 HR15N
30N HR30N Diamond cone 29·42 (3) 264·8(27) 294·2(30) 42·86 HR30N
45N HR45N Diamond cone 29·42 (3) 411·9(42) 441·3(45) 20·77 HR45N
15T HR15T Steel ball 1·587 5 mm 29·42 (3) 117·7(12) 147·1(15) 67·93 HR15T
30T HR30T Steel ball 1·587 5 mm 29·42 (3) 264·8(27) 294·2(30) 29·82 HR30T
45T HR45T Steel ball 1·587 5 mm 29·42 (3) 411·9(42) 441·3(45) 1·72HR45T
1.1 The hardness range for each scale and test force is dependent on the hardness and thickness of the test piece or surface layer tested. Guidance for tne choice of scale is given in Fig. 1.
IS 5072-1988 history
1989IS 5072-1988 Rockwell Surface Hardness Test Method (Scale 15N, 3ON, 45N, 15T, 30T and 45T)