SHORE HARDNESS

Shore scales are used to measure hardness: Shore A, B, C, D, 0 y 00.  The Shore A scale is the most suitable for measuring elastomers, although the Shore D scale can also be used for the measurement of hardness of harder gums. Approximately 40 Shore D correspond to 90 Shore A.

To determine the hardness of the rubber or elastomer, the most common and most frequent test is performed by measuring the strength of the rubber material at the penetration of a ball or a tipThere is no relationship between hardness and other mechanical properties as normally happens with steels.  Harder does not mean, for example, greater tensile strength. Materials with the same hardness can be completely different.

  • Shore A / D

The measurement is performed with an instrument called a durometer, based on the penetration of a frusta conical tip against the reaction of a calibrated metal spring. When readings above 90 ° are obtained with the Shore A durometer, it is recommended to use the Shore D durometer, which has a conical tip and a stiffer spring. Both methods are described in the Spanish standard UNE 53130, the American ASTM D2240 and the German DIN 53505.

There are several specific scales for measuring the hardness of very soft rubbers, cellular or spongy materials as well as a wide variety of different materials. The Shore 0 and shore 00 scales meet the specifications of ASTM D2240.

 

  • IRHD (International graduation of rubber hardness)

 

It is a method for characterizing an elastomer by its resistance to the penetration of a known geometric inventor by a known force. The readings are similar, but not identical, to the Shore (TM, Wilson – Shore Instruments) model.

 

ASTM D 1415

http://www.astm.org/Standards/D1415.htm

ASTM D 2240

http://www.astm.org/Standards/D2240.htm

DIN 53505

http://www.beuth.de/en/standard/din-53505/24622623

ISO 7619

http://www.iso.org/iso/catalogue_detail.htm?csnumber=50756

 

shore a irhd shore d shore 0 shore 00
DIN 53505 ASTM D 1415 DIN 53505 ASTM D 2240 ASTM D 2240
100 100 58
95 95 46
90 90 39
85 85 33
80 80 29 84 98
75 74 25 79 97
70 68 22 75 95
65 64 19 72 94
60 62 16 69 93
55 54 14 65 91
50 49 12 61 90
45 44 10 57 88
40 39 8 53 86
35 35 7 48 83
30 28 6 42 80
25 35 76
20 28 70
15 21 62
10 14 55
5 8 45
 

Compact and

cellular elastomers

Compact Elastomers Polyurethanes, rigid PTFE ,

Thermoplastics and hard

elastomers

Compact and celullars

wit half density

Elastomers

 

Half and low density

elastomers