Soft Vs. Hard Durometers: Understanding the ‘Shore Hardness Scale’ for Your Urethane Product Needs

Have you been searching for custom urethane products but are not quite sure what the ‘durometer’ (also known as ‘hardness’) you need for your specific application(s)? Do you wish there was an easier way to understand the various durometers available? Don’t worry. You are not alone, and fortunately, we’ve got the answer.

The durometer of urethane, the measurement of its hardness and the range at which it can be produced, is extremely versatile. Whether you are looking for products that are soft as a marshmallow or hard as a bowling ball, PSI Urethanes can formulate in a large range of durometers offering customers a variety of choices that best suit their urethane product needs.

In order to determine the ideal durometer needed, it is important to understand the basics of the Shore Hardness Scale (Shore OO, Shore A, and Shore D) – a standard method of measuring hardness – and the types of materials that fall under each durometer scale.

In the following blog post, we’ll provide you with common examples of materials used within each of the durometer scales.

Shore OO Hardness – Ideal for extremely soft materials

Durometers in the Shore OO scale range from 10 Shore OO to 70 Shore OO and are typically used for materials that are very fragile. Some examples include:

  • Vibration dampening
  • Shock absorption
  • Low-pressure seals and gaskets

Shore A Hardness – Ideal for all elastomers

Durometers in the Shore A scale range between 10 Shore A to 95 Shore A, and can be very soft and flexible, medium and slightly flexible, or hard with little flexibility.

Given the broad range of durometers in the Shore A scale, materials in this range are some of the most common types of elastomers produced. Urethane products produced with durometers in Shore A are well suited for industrial applications because of their versatility and resistance to tearing and abrasions.

Some common examples and characteristics of urethane products that you would consider for this range of durometers include:

  • 40 Shore A – Resilient, High Coefficient of Friction (Applications that require grabbing)
  • 60 Shore A – Bumpers, Metal forming, Feed Rollers
  • 90 Shore A – Rollers, Wheels

Shore D Hardness – Ideal for harder materials (including many rigid plastics)

Durometers in the Shore D scale consist of materials with the highest hardness and range from 50 Shore D to 70 Shore D. Materials in this range will typically include hard rubbers, semi-rigid or hard plastics and tend to have a high load-bearing capacity.

Some common examples and characteristics of urethane products that you would consider for this range of durometers include:

  • 60 Shore D – Very tough and resistant to tears
  • Forklift Tires, Rollers for heavy loads

Keep in mind that while durometer is a general indicator of other physical properties, it does not reflect the versatility that PSI’s urethane products can offer.

If you’re in need of custom urethane parts, let us know! With over 50 years in business and extensive experience with custom urethane products, we’ll be more than happy to guide you in selecting the right durometer needed for the job.