Shore Hardness


The Shore Hardness is a characteristic value that is used predominantly for elastomers, soft rubbers and very soft plastics. It is directly related to the indentation depth and serves as a measure of the material hardness. As indenter a truncated cone of tempered steel is used and forced into the specimen by a spring. The resulting indentation depth is a measure for the shore hardness.

According to the standard DIN 53505 (valid until 2012), a distinction is made between the hardness methods Shore A and D.

Shore Hardness A is used for soft rubbers and Shore Hardness D for elastomers and very soft plastics. The standard DIN ISO 7619-1, which has been valid since 2012, specifies corrected values for the indenter geometry of Shore Hardness D.

Hardness tester for Shore A and D as well as the Shore Indenter (according to DIN 53505)

Specimen Preparation

  • Specimen requirements: smooth, flat, plane-parallel and a minimum thickness given by the according standard (stacking possible)
  • Extraction of specimens from components

Testing Conditions

  • Device: ZWICK hardness tester 7206 (HHP 2001)
  • Air conditioning: standard climate (23 °C, 50 % humidity)

Measurements in accordance with DIN EN ISO 868

General

  • measurement time 15 s
  • 5 individual measurements
  • Minimum thickness 4 mm (also 3 times layered is possible)
  • Sample storage before testing 1 h (standard climate)

Shore A

  • Contact compression force 12.5 N ± 0.5 N
  • Shore A: truncate cone indenter with a diameter of 0.79 mm ± 0.03 mm and an opening angle of 35° ± 0.25°

Shore D

  • Contact compression force 50 N ± 0.5 N
  • Truncate cone indenter with a spherical cap, radius of 0.1 mm ± 0.012 mm and an opening angle of 30° ± 1°   

Measurements in accordance with DIN ISO 7619-1

General

  • Measurement time 3 s (vulcanised rubber) and 15 s (plasticised elastomer)
  • 5 individual measurements
  • Minimum thickness 6 mm (also 3 times layered is possible)
  • Sample storage before testing 1 h (standard climate)

Shore A

  • Contact pressured weight 1 kg + 0.1 kg
  • Shore A: truncate cone indenter with a diameter of 0.79 mm ± 0.01 mm and an opening angle of 35° ± 0.25°

Shore D

  • Contact pressured weight 5 kg + 0.5 kg
  • Truncate cone indenter with a spherical cap with a radius of 0.1 mm ± 0.01 mm and an opening angle of 30° ± 0.25°   

Measurements in accordance with DIN 53505

General

  • Measurement time 3 s (15 s with a strong flow behaviour)
  • 3 individual measurements
  • Minimum thickness 6 mm (also 3 times layered possible)
  • Sample storage before testing 16 h (standard climate)

Shore A

  • Contact compression force 12.5 N ± 0.5 N
  • Shore A: truncate cone indenter with a diameter of 0.79 mm ± 0.01 mm and an opening angle of 35° ± 0.25°

Shore D

  • Contact compression force 50 N ± 0.5 N
  • Truncate cone indenter with a spherical cap with a radius of 0.1 mm ± 0.01 mm and an opening angle of 30° ± 1°   

Accredited Standards

  • DIN EN ISO 868:
    Plastics and ebonite – Determination of indentation hardness by means of a durometer (Shore hardness) 
  • DIN ISO 7619:
    Rubber, vulcanized or thermoplastic – Determination of indentation hardness
    • Part 1: Durometer method (Shore hardness)
  • DIN 53505:
    Testing of rubber – Shore A and Shore D hardness test (withdrawn)

Contact

Dipl.-Wirtsch.-Ing. Stephan Arndt
Telefon: +49 (0)3461 30889-68
stephan.arndt@psm-merseburg.de

Quickinfo

Procedures

  • Shore hardness
  • Hardness testing on plastics

Results

  • Shore A
  • Shore D

Standards

  • DIN 53505
  • DIN ISO 7619-1
  • DIN EN ISO 868

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