Guide to Rubber Hardness Testing with IRHD Tester

Guide to Rubber Hardness Testing with IRHD Tester

Rubber is one of the most versatile components produced in the polymer industry. From pin to the plane, this material has numerous applications and distinct requirements in almost all verticals. Rubber is mostly not used in its natural form for industrial applications, it is mainly the mix and matches of the rubber which is used. These rubber components reflect distinct features and characteristics as per the use. Among the various features, Hardness is one of the most widely measured properties used to characterize rubber. In this blog section, we will let you know how the IRHD rubber hardness tester is utilized for evaluating the hardness of a rubber component. It is a form of rubber and plastic testing instrument.

The procedure and meaning of the Test

Hardness is one of the most important properties which determine the suitability of any rubber component for its intended use. The incorrect hardness of may defeat the basic purpose for which the component is designed. Thus, accurate and reliable determination of the hardness is of extreme importance in the rubber industry.

The IRHD test is a non-destructive form of rubber quality test and is the most preferred method for final product inspection in the rubber industry. The International Rubber Hardness Degrees (IRHD) scale has a range of 0 to 100, corresponding to the elastic modulus of 0 (0) and infinite (100), respectively.

The standard test method conducted involves pressing a piece of rubber with a known force for a given time, and measure how much the rubber indents in that time. The recorded deflection gained is then converted into a Scale of Degrees, with lower numbers such as 40° being soft and higher numbers such as 80° being hard. Once the range is decided, then much more scientific tests and controls are conducted to establish and maintain consistent manufacture of parts.

Presto IRHD Rubber Hardness Tester is a renowned testing machine used for the same purpose. It determines the hardness of rubber and related components. It is widely used in the rubber industry to evaluate this important property. It is equipped with a spherical indentor, which indents the sample under a minor and major Load. The differential indentation depth is measured and tabulated to read directly in ‘IRHD’ degrees.

It is built on a rigid metallic base plate and finished in Autumn Grey & Blue combination painting and bright chrome/zinc plating to give it a corrosion resistant finish. It is strictly manufactured as per ASTM and DIN standards. The equipment comes complete with a calibration certificate traceable to NABL approved laboratories.

Few Key features of the machine are:

• High-quality rugged structure with corrosion resistant main body
• Dial gauge to measure the deflection
• Lightweight and resilient
• Plunger rod for frictionless movement of indenter
• Fast Guiding Mechanism with plunger rod
• Single-handed hassle-free operation with Spherical Indenter
• Highly accurate test results


To know more information about its features, price, and technical specifications, give us a call at +91 9210903903 or email us at

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