The Squeeze That Proves Your Plastic Feels the Way It Should

A soft grip that feels right on a prototype can mould up too firm on the production line, and a housing that looks rigid enough can still dent under a fingernail the first time a patient actually handles it.

Hardness Testing answers the question a visual check or a quick squeeze-by-hand never can: exactly how much a material resists indentation under a fixed, calibrated force, expressed as a repeatable number a design team can actually spec against. Our Hardness Testing for plastics programme at the Oragadam laboratory presses a calibrated durometer indenter into every specimen and records the resulting scale reading, referenced to ASTM D2240 and ISO 868 — the two governing standards for indentation hardness of plastics and elastomers used across device housings, seals, grips, and soft-touch overmoulds.

Shore A hardness covers the softer end of the scale — the flexible tubing, gaskets, and elastomeric seals that need to stay pliable enough to function while still resisting tearing or permanent set. Shore D hardness covers the rigid end — device housings, structural ribs, and hard moulded components that need enough surface hardness to resist scuffing, denting, and wear over years of handling. Using the wrong scale on the wrong material gives a reading that’s technically a number but tells a design team almost nothing useful, which is why matching the durometer type to the material’s expected hardness range is the first decision our team makes before a single measurement is taken.

ASTM D2240 testing defines the indenter geometry, spring force, and reading procedure used across the US medical device and plastics industry, while ISO 868 testing sets the equivalent internationally recognized method, and running both on the same specimen batch lets a single test report satisfy FDA submissions and CE-marked device files together. Indentation depth is what the durometer actually measures at the point of contact, and the delayed 15-second reading captures how much the material relaxes and recovers after the initial indentation, since a viscoelastic polymer can show a very different hardness value the instant the indenter touches down versus a few seconds later. Manufacturers turn to Kiyo R&D Lab as one of the region’s trusted plastic testing services because a single missed hardness reading doesn’t surface as a data-sheet footnote — it surfaces as a grip that feels wrong in a patient’s hand or a housing that dents the first time it’s actually dropped. Running the full hardness panel under one accredited scope at Oragadam, with reports formatted for direct regulatory submission, is what turns a single durometer reading into evidence your quality team can actually stand behind.

Kiyo R&D Lab – Oragadam

Our durometer hardness testing suite is based at No.13, Srinivasa Perumal Street, Panapakkam, Serapanacheri, Greater Chennai, Tamil Nadu 601301.

Book Your Hardness Test Today

Talk to our Oragadam team about your seal, grip, or rigid moulded component — one of our core plastic testing services, run on the same specimen batch as your tensile, flexural, or impact programme.

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