COMPARISON BETWEEN SHORE AND ROCKWELL HARDNESS RANGES


HARDNESS CAN BE CONSIDERED IN SEVERAL WAYS. A ROCKWELL NUMBER IS DIRECTLY RELATED TO THE RESISTANCE OF A RIGID MATERIAL TO PENETRATION BY A STEEL BALL. SOFT PLASTICS AND RUBBERS ARE TESTED FOR RESISTANCE TO PENETRATION BY THE SHORE HARDNESS METHOD. HERE IS A GENERAL COMPARISON BETWEEN THE MOST COMMON SCALES OF HARDNESS:


CONVENTIONAL ELASTOMERS THERMOPLASTICS THEROMO-SETS
THERMOPLASTIC ELASTOMERS
20
A		 30
A		 40
A		 50
A		 60
A		 70
A		 80
A		 90
A		 100
A
40
D		 50
D		 60
D		 70
D		 80
D		 90
D
50
R		 60
R		 70
R		 80
R		 90
R		 100
R		 110
R		 120
R		 130
R		 140
R		 150
R
SOFT
HARD


HERE ARE SOME RELATIVE RANKINGS OF HARDNESS FOR SOME COMMON THERMOPLASTICS:


GENERIC TYPE TRADE NAME SUPPLIER VALUE
ELASTOMER KRATON 1107 2500 ( S ) A37
PVC UNICHEM 5790 COLORITE ( S ) A58
URETHANE ESTANE 58105 BF GOODRICH ( S ) A75
POLYETHYLENE EVA 3190 DUPONT ( S ) A85
STYRENE KRESIN KR01 PHILLIPS ( S ) D75
POLYCARB. /20%GF KA12003 FERRO ( R ) L80
PPRO / 40%GF RPP40DA01 FERRO ( R ) M59
ABS / 40%GF ST42015 FERRO ( R ) M102
NYLON 6 / 10 TECHNYL D316 RHONE POULENC ( R ) R94
NYLON 6 / 6 TECHNYL A221 RHONE POULENC ( R ) R100
NY66 / 40%CF NY23001 BK C FERRO ( R ) R120

( S ) = SHORE SCALE ( R ) = ROCKWELL SCALE




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