Urethane 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.

TABLETOP VIDEO: DUROMETER EXPLAINED

The durometer of urethane is the measurement of its hardness. The range at which it can be produced is reflected by The Shore Hardness Scale, which 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 polyurethanes 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.

Durometer Scales Explained

The durometer of an elastomeric material like polyurethane is measured as a discrete value on The Shore Hardness Scale. The Shore Hardness Scale contains many subsets which are categorized by letter. The softest materials fall within the Shore OO range. As material hardness increases, the scales advance from Shore A all the way up to Shore D. Harder materials than those in the Shore D scale are measured using another range called The Rockwell Scale. At PSI Urethanes we most commonly work with Shore OO, Shore A, and Shore D materials.

For a more in-depth look at how The Shore Hardness Scale works, visit our blog post, Understanding The Shore Hardness Scale.

Common Examples of Materials Used

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

Polyurethane Durometer Reference Calculator

The easiest way to understand different urethane measurements is by applying them to things that you are already familiar with. That’s why we’ve put together this polyurethane durometer reference calculator, which gives you everyday items that correspond to different Shore Hardness measurements. Give it a try!

Select Durometer

Select Hardness

For reference, this hardness is as soft as a Gel Shoe Insole

For reference, this hardness is as soft as a Rubber Band

For reference, this hardness is as soft as a Pencil Eraser

For reference, this hardness is as soft as a Tire Tread

For reference, this hardness is as soft as a Shopping Cart Wheel

For reference, this hardness is as soft as a Hard Hat

Custom Shore Durometer Urethane Parts

Keep in mind that while durometer is a general indicator of other physical properties, it does not reflect the full range of versatility that PSI’s custom 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.