Choosing the hardness of O-ring correctly is very important to ensure sealing and reliability. This paper will introduce the importance of its hardness selection and its selection suggestions. I hope everyone can choose the appropriate hardness according to their actual needs.

Hardness concept and testing method

Definition of hardness: the hardness of rubber sealing ring refers to its resistance under the action of external force, and can also be understood as its elastic characteristics. Hardness values are usually expressed in units such as "Shore A" or "Shore D".

Test method: Hardness test is completed by a hardness tester. Commonly used hardness testers are Shore A hardness tester and Shore D hardness tester. The needle tip of the hardness tester will be pressed into the surface of the rubber sealing ring to a certain depth, and then the hardness value can be obtained by reading the depth into which the needle tip enters.

Importance of hardness selection

1. Anti-compression deformation: Rubber O-ring may undergo compression deformation under long-term compression, especially under high pressure or high temperature environment. Proper selection of hardness can reduce the occurrence of compression deformation and ensure sealing and service life.

2. Sealing: The hardness of rubber sealing ring directly affects its deformation and resilience after compression. Rubber sealing rings with too low hardness are prone to excessive deformation, resulting in insufficient sealing performance, resulting in leakage and damage.

3. Wear resistance: Rubber sealing rings with higher hardness usually have better wear resistance and oil resistance, and are suitable for some applications with high wear and harsh working conditions.

Factors affecting hardness selection of rubber sealing ring

1. Working pressure: The working pressure directly affects the compression deformation of the sealing ring. In high pressure environment, it is necessary to choose rubber sealing ring with lower hardness to reduce compression deformation and maintain sealing performance. In low pressure environment, rubber sealing ring with higher hardness can be selected to improve its elasticity and resilience.

2. Medium properties: Different media have different requirements on the hardness of rubber materials. For example, oil-related media need O-rubber sealing rings with good oil resistance, and materials with higher hardness are usually selected.

3. Working temperature: Working temperature is one of the important factors in selecting the hardness of rubber sealing ring. In high temperature environment, rubber usually hardens, so it is necessary to choose a rubber sealing ring with lower hardness to maintain its tightness. In low temperature environment, rubber will become soft, so it is necessary to choose a rubber sealing ring with higher hardness to improve its elasticity and cold resistance.

4. Service life: Service life is an important consideration in hardness selection. Too high or too low hardness will affect the service life of rubber sealing ring. Reasonable selection of hardness can prolong the service life of rubber sealing ring.

Suggestions on hardness selection

1. Periodic test: Testing the hardness of rubber O-ring regularly is the key to ensure its stable performance. The test results can be used as the basis for adjusting hardness selection.

2. Select a reliable manufacturer: select a reliable rubber product manufacturer to ensure that O-rings that meet the standard requirements are provided, and their hardness values are accurate and reliable.

3. Selection according to actual demand: According to specific working environment, temperature, pressure, medium and other requirements, select rubber sealing ring with appropriate hardness.

It can be known that the hardness value directly affects the sealing, pressure resistance and wear resistance of rubber O-ring. When selecting rubber sealing ring, customers should fully understand the concept and testing method of hardness, and ensure that the hardness of the selected rubber sealing ring reaches the standard through correct hardness selection according to actual needs.