When designing custom silicone components, one of the most important – and sometimes overlooked – considerations is durometer, or material hardness. The durometer you choose can directly affect your part’s flexibility, tactile feel, durability, and even its appearance.

At SiTech, we offer silicone molding in a range of durometers to meet the diverse needs of our customers, helping ensure each part performs exactly as intended.

What Is Durometer?

Durometer is a measure of a material’s hardness or resistance to indentation. For silicone, the Shore A scale is used. This scale typically ranges from 10 to 90, with higher numbers indicating harder materials.

Here’s a basic reference:

• 40 Shore A – Very soft and flexible, like a soft rubber eraser
• 50 Shore A – Slightly firmer with good translucency properties
• 60 Shore A – Industry standard; offers a balance of flexibility and durability
• 70 Shore A – Firm, ideal for components needing structural integrity
• 75 Shore A – Very firm; used in rugged applications or when minimal flex is required

Our Standard Durometers

At SiTech, we routinely work with:

• 40, 50, 60, 70, and 75 Shore A silicone

Our standard durometer is 60 Shore A, which offers an excellent balance of tactile response and mechanical strength. It’s a versatile option suitable for most keypad and interface applications.

We often recommend 50 Shore A for parts requiring translucency, as this durometer level allows more light transmission while maintaining good durability and flexibility.

Why Durometer Matters in Silicone Parts

Choosing the right durometer can impact several performance aspects:

• Tactile Feedback – Softer silicones (like 40A or 50A) provide a cushioned feel, while harder silicones (70A or 75A) deliver a more rigid response.
• Flexibility – Lower durometers bend and compress easily, making them ideal for seals, gaskets, or parts that require frequent actuation.
• Durability – Higher durometer silicones resist wear and tear in high-use or harsh environments.
• Appearance – Lower durometers are better for translucent or light-passing parts, especially in backlit applications.
• Design Fit – Certain assemblies may require firmer or softer silicone to achieve proper compression or sealing within housings.

Tailored for Your Application

Whether you’re developing a medical device interface, an industrial control panel, or a backlit marine keypad, we’ll help you choose the right durometer to meet your performance and aesthetic goals.

Not sure where to start? Our team is happy to provide design recommendations based on your product’s end use, environmental conditions, and visual requirements.

Contact SiTech today to learn more about our silicone molding capabilities and how different durometers can elevate your product performance.