Port Geometry and Gasket Seating on a Pressure Part
Controlled gland squeeze between 15% and 25% prevents mechanical die stress while isolating the pressure port against long-term fluid leakage.
Durometer Shore A
Hardness Measurement Scale
A standardized method quantifies the resistance of elastomers and soft plastics to permanent surface indentation. Practitioners use durometer shore a to determine the suitability of seals or gaskets for specific pressure ratings. The scale spans from zero to one hundred based on the depth of a truncated cone indenter pressing into the material.
Mechanical Indenter Geometry
The hardware consists of a hardened steel rod with a tip angled at thirty-five degrees. A calibrated spring applies a specific force profile to the probe during the test. Because the shape of the tip is fixed by international standards, the durometer shore a reading provides a repeatable metric for material density and cross-linking.
Temporal Loading Effect
Viscoelastic materials continue to deform under a constant applied load. A measurement taken immediately upon contact often yields a higher durometer shore a value than one recorded after a ten second dwell period. Standard procedures require the foot of the instrument to remain flush against the specimen to prevent parallax errors or rocking.
Reliable data depends on the technician applying the load steadily without any impact or lateral movement.
Range Application
Soft rubbers and flexible PVC typically fall within the middle of the range. If a specimen returns a durometer shore a value higher than ninety, the material is considered too hard for the specific indenter and requires testing with a sharper shore d point.