When buyers ask how to specify silicone hardness, the answer should never stop at a single Shore value. Hardness only becomes meaningful when it is tied to part form, installed thickness, compression path and the real assembly condition. A gasket that seals by squeeze, a profile that must flex into a channel, a thermal pad that needs controlled stack-up, and a molded part that indexes against several surfaces all use the same words in different ways.
Forvard Tech treats hardness, thickness and compression as a linked RFQ package rather than three isolated fields. This article explains how procurement and engineering teams can state those inputs more clearly so early quotations stay aligned with the real design review.
1) Start with the part form before naming the hardness target
Silicone hardness is not a standalone purchasing shortcut. The same nominal hardness can behave very differently depending on whether the part is a flat gasket, an extruded profile, a molded component or a converted pad. Before stating a hardness request, identify the actual part form and sealing function.
A more useful opening package usually includes:
- Part form: gasket, profile, molded part, tubing, pad or sheet-converted seal.
- Whether the part is meant to seal, cushion, locate, protect or fill an interface.
- Whether the part is static, removable or repeatedly compressed during service.
- Whether the current request is a concept-stage comparison or a drawing-based RFQ.
For projects that may route into different silicone formats, these product pages help frame the review:
2) Hardness should describe functional behavior, not only a number
Buyers often send a requested hardness without explaining why that value matters. In practice, the supplier still needs to know what the hardness is expected to do in the assembly. Is the target meant to support compression recovery, insertion feel, edge stability, surface conformity or handling during installation? Those are different review questions.
If the target hardness comes from an existing part, say whether it is a current production baseline, an approved sample or only a starting reference. If the project is still open, it is better to state the functional goal and the preferred scale, such as Shore A or another agreed method, than to imply that one exact value is already frozen.
- Whether softer material is being considered for conformity or sealing contact.
- Whether firmer material is being considered for handling, support or geometry retention.
- Whether color, finish or reinforcement choices could affect material selection.
- Whether the project requires comparison samples rather than a single final target.
3) Thickness belongs to the installed interface, not just the free-state part
Thickness is often the missing field in early silicone RFQs. For a sealing or cushioning part, thickness only becomes useful when buyers explain how the material sits in the actual assembly. Free-state thickness alone may not tell the supplier enough about squeeze, stack-up or tolerance sensitivity.
This is especially important when the same project can be handled as a converted gasket, a profile section or a molded geometry. If the thickness dimension is critical, mark whether it controls sealing contact, assembled height, gap coverage or insertion clearance.
- Nominal thickness or wall section and which dimensions are critical.
- Whether the dimension is measured before assembly, after assembly or both.
- Whether the mating parts are rigid, uneven or tolerance-sensitive.
- Whether the section changes across the part and needs a drawing view.
When the geometry is still developing, pair the thickness note with the drawing status and sample stage rather than presenting it as a final production value.
4) Compression should be stated as an assembly condition
Compression language becomes vague very quickly if the RFQ only says “needs compression” or “must not deform.” The useful question is how the part is compressed inside the real interface. Compression can refer to sealing squeeze, gap-fill loading, door closure force, repeated clamping or long-duration static load.
That is why buyers discussing long-term sealing should also review:
A practical RFQ states what the part looks like before assembly, how it sits after assembly and whether the load is continuous or cycled. It should also separate the compression condition from any unsupported life or performance promise. The website can discuss review logic, but it does not promise fixed recovery results or universal service-life outcomes.
5) Keep hardness, thickness and compression in the same conversation
These three inputs should not be collected by different people in isolation. Hardness affects how a part reacts at the stated thickness, and both matter only in relation to the compression condition. If one field changes, the others may need to be rechecked.
A responsible engineering handoff usually answers:
- What is the free-state section or nominal thickness?
- What is the installed or compressed condition?
- What functional role is the material expected to perform at that state?
- Is the target based on an existing part, a drawing or a trial build?
- Which dimensions are critical to fit and which are only reference dimensions?
That combined view helps avoid RFQs that ask for one hardness value while leaving the installed geometry undefined.
6) Add tolerance and sample-stage context early
Many sourcing delays happen because the RFQ names a hardness and thickness target but says nothing about tolerance expectations or sample stage. Early comparison samples can stay broader, while release-stage RFQs should identify the dimensions and conditions that actually control fit.
State whether the request is for:
- Feasibility review.
- Sample comparison.
- Drawing-based quotation.
- Pre-production confirmation.
If the part has several thickness zones, ribs, lips or hollow sections, note that clearly. This is often the point where a project moves from a simple sheet part into a profile or molded-part discussion.
7) Keep testing, compliance and document requests project-specific
Testing and document language should support the RFQ, not replace it. If the project needs hardness verification, dimensional inspection, compression-related review or customer-specific records, say what is required and at which project stage. Do not turn the request into a blanket assumption about every batch, every market or every application.
Forvard Tech keeps that boundary explicit through:
Public content can explain how to specify silicone hardness, thickness and compression, but it does not promise unrestricted certification coverage, automatic acceptance or fixed performance values.
8) What to send before RFQ submission
If your team is preparing a silicone part RFQ, send the drawing or section view, target hardness scale, nominal thickness, installed compression condition, application role, quantity stage and any inspection or document expectations together. That gives the engineering review enough context to decide whether the part should stay in a gasket route, move into profile design or shift into a molded-part review.
Next step: submit the current part drawing or section, target hardness scale, free-state thickness, installed compression condition and project stage through the RFQ path so the quotation discussion stays tied to the real assembly.