Silicone and Elastomers in Manufacturing
Elastomers are specified by durometer and compound, not by family, and silicone, EPDM, Viton, and nitrile are chosen against different chemistry. What a capability page needs to state.
Elastomers are specified by compound and durometer rather than by family, and silicone, EPDM, Viton, and nitrile are selected against the chemistry they will see. A request naming rubber has not specified a material.
Elastomer selection is a chemistry decision dressed as a materials one, and the failure is always the fluid rather than the load. The programme argument is in manufacturing SEO.
The compounds and what selects them
An elastomer compound is selected against the fluid and the temperature it will see, not against a strength requirement.
Silicone covers wide temperature range and poor oil resistance. Nitrile covers oil and fuel and poor ozone resistance. EPDM covers water, steam, and weather and fails immediately in petroleum. Viton covers aggressive chemistry and high temperature at a considerably higher cost.
Choosing wrongly produces a seal that swells, hardens, or dissolves in service, and it is the most common elastomer failure by a wide margin.
Durometer is the other half
Durometer records hardness on a Shore scale, and it changes sealing force, compression set, and how the part installs.
A drawing calling a compound without a durometer has specified half the material, and a supplier quoting without asking has guessed at the half that governs the fit.
Compression set is what determines whether a seal still seals after a year under load, and it is a compound property rather than a durometer one, which is why the two are stated together.
What drives the quote
Elastomer work is usually moulded rather than machined, so tooling dominates the first order and the per-part cost afterwards is small. That inverts the arithmetic on prototypes: tooling cost governs a low-volume elastomer quote, and a buyer expecting machining economics is surprised.
Platinum-cure silicone is the regulated-service grade, used where extractables matter, and it is specified for pharmaceutical and food-contact work covered at pharmaceutical manufacturing.
What a capability page should state
A capability page must state process, materials, tolerances, capacity, certifications, and industries served, and elastomers belong there by compound and durometer range.
State the compounds run, the durometer range, whether tooling is made in-house, and which cure systems are available. Where the work is regulated, name the compliance the compound carries rather than the family.
The structure is at capability page structure and the cluster reasoning at materials.
Common questions
Why does the fluid decide the material?
Because chemical attack rather than mechanical load is what fails a seal. Strength rarely decides an elastomer selection.
What durometer should a seal be?
The one the groove and sealing force require. It is a design input rather than a supplier preference and it belongs on the drawing.
Is silicone always food safe?
No. Compliance belongs to the compound and its cure system, not to silicone as a family, and platinum cure is the usual requirement.
Why is Viton so expensive?
Fluoroelastomer chemistry. It is specified where nothing cheaper survives the service rather than as an upgrade.
Last reviewed . Published by ManufacturingSEO.ai.