How do you measure the hardness of rubber?
Shore hardness is measured with a device known as a Durometer, hence the term ‘Durometer hardness’. Hardness value is determined by the penetration of the Durometer indenter foot into the sample being tested.
What is hardness in rubber?
What is Shore Hardness? Rubber shore hardness is the measure of the resistance a rubber material (like Silicone or EPDM) has to indentation, or quite simply, the hardness of the rubber.
What is the difference between Irhd and Shore A hardness?
The IRHD test is usually non-destructive, and as such has to be the preferred method for final product inspection; the test takes 35 seconds. In contrast, the Shore method is often destructive (leaving a permanent indentation), but the test only takes 1 or 3 seconds.
How do Durometers work?
The principle used to measure hardness is based on measuring the resistance force of the penetration of a pin into the test material under a known spring load. The amount of penetration (max. 2.5 mm) is converted to hardness reading on a scale with 100 units.
What does 70 Duro mean?
The hardness of rubber compounds is measured by the Shore A durometer; the higher the durometer, the harder the compound. 70-durometer hardness should be used whenever possible as it offers the best combination of properties for most O-Rings applications.
What is 60A hardness?
Shore 60A = Car Tire Tread. d. Shore 70A* = Running Shoe Sole. e. Shore 80A = Leather Belt.
What is the difference between Shore A and Shore D?
The major differentiation between the Shore A and Shore D is that Shore A is specified to measure flexible rubbers while Shore D is specified for harder, rigid materials. However, the ranges do tend to overlap at higher levels.
What is Shore M hardness?
Type (Shore) M Durometer Type M durometer is described as a micro hardness gauge. It is appropriate for measuring the hardness of specimens that cannot be accurately measured using the Shore A device like orings.
How do you calculate shore?
Shore hardness is tested with an instrument called Durometer. Durometer utilizes an indenter loaded by a calibrated spring. The measured hardness is determined by the penetration depth of the indenter under the load.
How hard is 70A Durometer?
A 70A rubber (as hard as a car tire) is stiff and would not offer enough flexibility to extract this model without breaking it. A better choice would be a Shore 30A rubber or softer that would offer enough flexibility to easily extract the model.
What is the unit of hardness?
The SI unit of hardness is N/mm². The unit Pascal is thus used for hardness as well but hardness must not be confused with pressure. The different types of hardness discussed above have different scales of measurement.
What is the International Rubber hardness degree (IRHD)?
The International Rubber Hardness Degree according DIN ISO 48 – Part 1 is, beside the Shore hardness, another test method for the measurement of the rubber hardness. IRHD shows the resistance of a rubber specimen against the intrusion of a ball with a diameter of 2.5 or 5.0 mm respectively under a defined pressure.
How do you calculate the IRHD of a durometer?
IRHD ~= Shore A + 4 **This is an approximate equation**. …so 60 shore A is approximately equal to 64 IRHD.”In 1993, Briscoe and Sebastian analysed the durometer indentation, providing an approximate relationship between IRHD and Shore A of (IRH ª HA + 4), although this is very dependent on the sample compound”.
How do you measure the shore a hardness of rubber?
Determining the Shore A hardness of rubber. The most commonly used method is the Shore A measurement. This measurement follows the ISO 7619-1 standard, where the test material has a thickness of 6 mm. A disadvantage of this method is that for smaller and thin products it is not possible to measure the hardness of the rubber.
How do you calculate IRHD from shore a?
IRHD ~= Shore A + 4 **This is an approximate equation** …so 60 shore A is approximately equal to 64 IRHD.”In 1993, Briscoe and Sebastian analysed the durometer indentation, providing an approximate relationship between IRHD and Shore A of (IRH ª HA + 4), although this is very dependent on the sample compound”