GB/T 6031-2017
Rubber, vulcanized or thermoplastic—Determination of hardness (hardness between 10 IRHD and 100 IRHD) (English Version)

Standard No.

GB/T 6031-2017

Language

Chinese, Available in English version

Release Date

2017

Published By

中华人民共和国国家质量监督检验检疫总局、中国国家标准化管理委员会

Latest

GB/T 6031-2017

Replace

GB/T 6031-1998

Scope

This standard specifies four methods for determining the hardness of vulcanized rubber or thermoplastic rubber with a flat surface (standard hardness method) and four methods for determining the apparent hardness of samples with curved surfaces (apparent hardness method). Hardness values are expressed in International Rubber Hardness (IRHD). The applicable hardness range for these determination methods is from 10 IRHD to 100 IRHD. The main difference between these methods lies in the diameter of the spherical indenter and the magnitude of the force, and the appropriate method should be selected according to the specific application. The scope of application of each method is shown in Figure 1. This standard does not specify a method for the determination of hardness using a portable hardness tester, which is described in ISO 7619-2. This standard stipulates the following four methods for measuring standard hardness: Method N (conventional test): It is suitable for rubber hardness within the range of 35 IRHD~85 IRHD, and can also be used for rubber with hardness within the range of 30 IRHD~95 IRHD. Method H (high hardness test): suitable for rubber hardness in the range of 85 IRHD~100 IRHD. Method L (low hardness test): suitable for rubber hardness in the range of 10 IRHD~35 IRHD. Method M (Miniature Test): Essentially a scaled down Method N (Normal Test) that can be used for thin, small specimens. It is suitable for rubber hardness within the range of 35 IRHD~85 IRHD, and also can be used for rubber with hardness within the range of 30 IRHD~95 IRHD. This standard also provides CN, CH, CL and CM four methods for measuring the apparent hardness of curved surfaces. These methods are modifications of methods N, H, L and M for the case where the rubber surface to be tested is curved, in which case there are two main possibilities: a) The test specimen and product are large enough that the durometer can or b) the specimen and product are small enough that the specimen and hardness tester can be placed on a common support. Alternatively, the sample can be placed on the sample stage of the hardness tester. For non-standard uneven samples, methods N, H, L and M can also be used to measure the apparent hardness. The above methods are not guaranteed to be suitable for all shapes and sizes of specimens, but include some of the most common types such as "O" rings. This standard does not specify the method for determining the apparent hardness of rubber rollers. See ISO 7267 (all parts) for relevant test methods.

GB/T 6031-2017 Referenced Document

• GB/T 2941-2006 Rubber. General procedures for preparing and conditioning test pieces for physical test methods
• ISO 18898 Rubber - Calibration and verification of hardness testers

GB/T 6031-2017 history

• 2017 GB/T 6031-2017 Rubber, vulcanized or thermoplastic—Determination of hardness (hardness between 10 IRHD and 100 IRHD)
• 1998 GB/T 6031-1998 Rubber, Vulcanized or thermoplastic--Determination of hardness (hardness between 10 IRHD and 100IRHD)
• 1985 GB 6032-1985 Determination of international hardness of vulcanized rubber (30 ~ 85IRHD) micro test method