A custom silicone quotation is not based only on the visible shape or finished product weight. The manufacturer also needs to understand mold structure, wall thickness, undercuts, parting-line position, demolding direction, material and hardness, critical tolerances, expected quantity, testing, appearance, packaging, and the relationship between the silicone part and the mating assembly.

That is why the quality of your silicone RFQ files directly affects the speed and accuracy of the manufacturing review. A complete file package allows Reemane to identify production risks before tooling, separate confirmed requirements from open questions, and provide a quotation based on the actual project rather than assumptions.

Reemane can begin reviewing a project from STEP files, 2D drawings, physical samples, photographs, sketches, basic dimensions, or a written product concept. You do not need to wait until every detail is finalized before contacting us. However, accurate mold and production pricing requires enough confirmed information to define what will ultimately be manufactured and approved.

Why the RFQ Input Package Matters

Two silicone products that look similar can require very different tooling and production methods. A shallow flat gasket may be simple to mold and demold, while a deep protective sleeve of similar weight may require long cores, controlled wall thickness, difficult demolding, and additional inspection.

The information provided at the RFQ stage helps determine:

• Whether silicone compression molding is suitable
• Possible mold-opening and demolding directions
• Parting-line and flash locations
• Whether removable cores or multi-part tooling are required
• Material usage and practical cavity quantity
• Critical tolerances and inspection effort
• Sample quantity and approval requirements
• Secondary operations such as trimming, post-curing, printing, assembly, or cleaning
• Packaging needed to prevent contamination or deformation
• The mold cost, unit-price direction, and development schedule

When important information is missing, the supplier may quote using assumptions that later prove incorrect. This can lead to revised tooling costs, delayed samples, additional mold changes, inspection disagreements, or a product that looks correct but fails during installation or use.

What a STEP File Provides

A STEP or STP file is a neutral product-data exchange format commonly used to transfer three-dimensional CAD geometry between different engineering and manufacturing systems. For a custom silicone project, it is usually the most useful file for understanding the complete shape of a complex molded component.

A STEP file can help Reemane review:

• External and internal product geometry
• Overall dimensions and approximate material volume
• Wall-thickness variation
• Ribs, lips, holes, grooves, sealing edges, and internal features
• Deep cavities and long mold cores
• Undercuts and possible removable-core requirements
• Likely mold-opening and demolding directions
• Possible parting-line positions
• Areas that may trap air or be difficult to fill
• Sections that may tear or deform during demolding
• The relationship between the silicone part and the mating component

STEP files are particularly useful for custom silicone covers, sleeves, caps, plugs, grommets, bushings, seals, irregular housings, grips, equipment boots, and products with complex three-dimensional surfaces.

Can a STEP File Contain Tolerances and Manufacturing Information?

Some STEP workflows can include product manufacturing information such as dimensions, tolerances, datums, notes, and other model-based definition data. However, many STEP files received during ordinary RFQ work are exported as geometry-only models.

Therefore, do not assume that every supplier will see all design requirements simply because a STEP file was attached. When sending the model, tell the manufacturer whether it contains controlled product manufacturing information and which document or model revision is authoritative.

What May Still Be Missing from a STEP File?

A geometry-only STEP export may not clearly communicate:

• Which dimensions are critical to function
• Dimensional and geometric tolerances
• Measurement datums and inspection direction
• Silicone type and target Shore A hardness
• Color and Pantone direction
• Surface texture, gloss, or visible-side requirements
• Flash and parting-line limits
• Logo, engraving, printing, or marking requirements
• Functional testing and acceptance criteria
• Packaging, labeling, and documentation requirements
• Drawing or model revision status

What a 2D Drawing Provides

A 2D drawing tells the manufacturer what must be controlled, measured, and accepted. It converts the product design into a manufacturing and quality document.

A useful silicone part drawing may include:

• Overall dimensions
• Critical dimensions and tolerances
• Datums and measurement orientation
• Wall thickness and local thickness requirements
• Hole, groove, lip, sealing, and assembly dimensions
• Silicone material or material-performance direction
• Target Shore A hardness and acceptable range
• Color and surface-finish requirements
• Texture, gloss, and visible-side identification
• Permitted parting-line and flash locations
• Logo, printing, engraving, or marking notes
• Functional test and inspection requirements
• Packaging, cleanliness, and labeling instructions
• Drawing number, revision, and release status

Flexible silicone parts are more difficult to measure than rigid metal or plastic components because the measuring force can bend, stretch, or compress the part. The drawing should therefore identify which dimensions matter to fit, sealing, grip, retention, or assembly and, where necessary, define how those dimensions should be measured.

Why a 2D Drawing Alone May Not Be Enough

A drawing may be sufficient for a simple washer, O-ring, flat gasket, basic cap, or plug. Complex curved products can be difficult to define through flat views alone.

Risks include:

• Hidden geometry may be misunderstood.
• Curved surfaces may not be completely defined.
• Wall-thickness transitions may be overlooked.
• Undercuts may not be obvious.
• The relationship between several features may be interpreted differently.
• The supplier may need to rebuild the 3D model before mold design.

Which File Should Control When the STEP Model and Drawing Conflict?

The RFQ should clearly identify which document is authoritative. Do not send a STEP file from one revision and a drawing from another without explaining the difference.

A practical file-control statement can be:

If your company uses a model-based definition system, state that the annotated digital model is the governing document and identify the required model revision and viewing method.

Revision control is important because a mold can be manufactured correctly according to one file while still being incorrect according to another. Before quotation, confirm that the STEP file, drawing, assembly file, RFQ form, and sample description all refer to the same product revision.

What a Physical Sample Provides

A physical sample is the most useful input when the original CAD is unavailable, when an existing component must be reproduced, or when a current design is failing.

A sample can help communicate:

• The real free-standing product shape
• How the part bends, stretches, compresses, or grips
• Approximate hardness and flexibility
• Surface texture, gloss, and appearance
• Color direction
• Parting-line and flash appearance
• How the part is installed or removed
• How it fits the mating component
• Areas that have torn, leaked, slipped, swollen, worn, or deformed
• The quality level expected by the buyer

Physical samples are especially valuable for replacement seals, legacy equipment parts, custom protective covers, equipment handle sleeves, caps, plugs, grommets, grips, boots, and products originally developed by another supplier.

Why a Physical Sample Is Not Automatically the Original Specification

A used sample may no longer match the dimensions or properties of the original manufactured part.

It may have:

• Shrunk after heat exposure
• Swollen after contact with oil or chemicals
• Stretched during installation
• Flattened after long-term compression
• Worn at a sealing or gripping surface
• Been manually trimmed after molding
• Changed flexibility during aging
• Been damaged during removal

A hardness reading taken from an old finished sample may support comparison, but it does not prove the exact original compound or material specification. Part thickness, surface condition, aging, temperature, and the test method can affect the reading.

A sample also does not reveal the original drawing tolerance, mold shrinkage allowance, approved free-state dimension, material formulation, inspection method, or acceptance standard.

For reverse engineering, send the sample together with:

• Photographs of the complete assembly
• The mating component or its dimensions
• The intended product function
• Operating temperature and contact media
• A description of the current failure
• Any available old drawing or specification
• The required prototype and production quantities

What Is Best for Different Silicone RFQ Scenarios?

New Custom Silicone Product

Send a STEP file and a controlled 2D drawing. Add the mating component or assembly file when sealing, fit, grip, stretch, retention, or installation depends on another product.

Existing Product Without Original CAD

Send the physical sample, clear photographs, available dimensions, application description, and mating product when possible. The sample can be used as the starting point for measurement and 3D reconstruction.

Replacement Seal or Gasket

Send the existing seal together with the groove or housing dimensions. Include pressure direction, operating temperature, contact media, surface condition, and the current leakage or compression problem. The damaged seal alone may not reveal the correct replacement geometry.

Protective Cover or Stretch-Fit Sleeve

Send the STEP model of both the silicone sleeve and the protected component. If CAD is unavailable, provide the equipment handle or mating part, detailed dimensions, and photographs showing the installation direction and required covered area.

Product Made Incorrectly by Another Supplier

Send the failed sample, the approved reference sample if available, the current drawing, assembly photographs, defect photographs, and operating conditions. Clearly identify what must be changed and which dimensions or features must remain unchanged.

Early Product Concept Without CAD

Send sketches, reference images, basic dimensions, intended use, installation method, functional requirements, target quantity, and the product or equipment the silicone part must fit.

Reemane can begin an early feasibility discussion from this information. Accurate tooling quotation normally follows after the product structure and critical dimensions have been sufficiently defined.

Are STL, IGES, Native CAD, PDF Drawings, or Photos Useful?

STL Files

STL files can communicate the visible three-dimensional form, but they are mesh-based. They may be less suitable than a solid STEP model for precise feature editing, dimensional changes, wall-thickness review, and mold-development work.

An STL can still support an initial review when no solid CAD format is available.

IGES or IGS Files

IGES files can be reviewed when a STEP file is unavailable. The imported file should be checked for missing surfaces, open edges, duplicate geometry, or other translation problems before mold development.

Native CAD Files

Native CAD files may contain useful design history, assemblies, configurations, and model-based information. However, software-version compatibility should be confirmed. Providing a neutral STEP export together with the native file can reduce access problems.

PDF Drawings

A dimensioned PDF drawing is useful for quotation and inspection discussion when it clearly shows units, dimensions, tolerances, material notes, revision status, critical features, and sufficient views.

Photographs

Photographs are useful for understanding the assembly, installation direction, appearance, current failure, and general scale. They do not reliably define hidden geometry, wall thickness, or dimensional tolerances.

When using photographs, include:

• Front, rear, side, top, and bottom views
• Close-up images of critical details
• Photographs of the part installed
• A ruler or caliper showing scale
• Images of damaged or failing areas
• Photographs of the mating component
• An explanation of which surfaces contact each other

Silicone-Specific Information That CAD Files Do Not Replace

Even a complete geometric model does not define the entire manufacturing requirement. A silicone RFQ should also explain how the part will function and what environment it will experience.

Include:

• Target silicone type or required performance direction
• Preferred Shore A hardness
• Color and visual requirements
• Operating temperature range
• Contact with oil, water, cleaning agents, chemicals, food, or other media
• Outdoor UV, ozone, rain, or moisture exposure
• Required sealing, grip, fit, cushioning, protection, or insulation function
• Whether the part will be repeatedly installed and removed
• Expected cleaning or sterilization method, where relevant
• Target market and testing requirements
• Prototype quantity, first production quantity, and annual usage
• Packaging, labeling, cleanliness, or deformation-prevention needs

If the material has not been selected, explain the application rather than choosing a grade only by name. Reemane can discuss material and hardness direction after reviewing the product structure and service conditions.

What Reemane Reviews Before Quoting

After receiving the available project files, Reemane reviews the complete manufacturing route rather than only the visible shape.

The review may include:

• Compression-molding feasibility
• Wall thickness and thick-to-thin transitions
• Possible parting-line position
• Undercuts and mold-action requirements
• Air-trap and material-flow risks
• Demolding direction and tearing risk
• Material and hardness direction
• Critical tolerances and measurement method
• Mating-part fit and assembly method
• Surface texture, logo, color, and visible areas
• Prototype quantity and sample-approval plan
• Production quantity and practical cavity layout
• Trimming, post-curing, printing, cleaning, or assembly
• Testing, documentation, packaging, and labeling

Learn more about Reemane’s

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Common RFQ Mistakes That Delay Quotation

Sending Only a Screenshot

A screenshot may communicate the concept, but it does not reliably define scale, hidden geometry, wall thickness, or tolerances.

Sending Different Revisions

A STEP model, drawing, assembly file, and RFQ form should describe the same product revision. Conflicting files create a serious risk of incorrect tooling or quotation.

Sending a Drawing Without Units

Clearly state whether dimensions are in millimeters or inches. Do not rely only on the original CAD software setting.

Providing No Quantity

Prototype quantity, first production quantity, and annual usage affect mold cavity quantity, process planning, unit price, inspection, and packaging.

Showing Only the Silicone Part

A cover, seal, sleeve, grommet, cap, or plug often depends on another component. Include the mating product, groove, housing, or assembly dimensions whenever possible.

Applying Tight Tolerances to Every Dimension

Unnecessary tight tolerances can increase mold development, inspection, sorting, and rejection costs. Identify the dimensions that genuinely affect fit, sealing, grip, retention, or assembly.

Sending an Old Sample Without Explaining Its Condition

State whether the sample is new, used, damaged, swollen, compressed, stretched, or already considered defective. This prevents the worn condition from being treated as the intended design.

Not Explaining the Product Function

A dimension that controls appearance is different from one that controls sealing or retention. Explain what the silicone part must do, not only what it looks like.

How to Prepare Your Silicone RFQ Files

1. Use a clear project and part name.
2. Include the current drawing and model revision.
3. State the measurement units.
4. Confirm which document or model controls the requirements.
5. Mark dimensions that are critical to function.
6. Identify silicone material and hardness direction.
7. Include the mating component when fit or sealing is involved.
8. Explain the operating and cleaning environment.
9. State prototype and production quantities.
10. List testing, documentation, packaging, and labeling requirements.
11. Explain any existing failure or reason for changing suppliers.

Frequently Asked Questions

Is a STEP file enough to quote a custom silicone part?

It may be enough for an initial geometry and mold-feasibility review. A reliable quotation usually also requires material and hardness direction, critical tolerances, quantity, application conditions, appearance requirements, testing, and packaging information.

Can a STEP file include tolerances?

Yes, some STEP workflows can include product manufacturing information such as dimensions, tolerances, datums, and annotations. However, many RFQ STEP files are exported as geometry only. Tell the manufacturer whether controlled model-based information is included.

Is a 2D drawing required when a STEP file is available?

A controlled drawing is strongly recommended when the project has critical tolerances, material notes, surface requirements, inspection criteria, or revision-control needs. It may not be necessary when a complete model-based definition is used and clearly identified as the governing requirement.

Can Reemane make a silicone part from a physical sample?

Yes. A sample can be used as a reverse-engineering starting point. The review is more reliable when you also provide assembly photographs, mating-part dimensions, application conditions, required function, and information about whether the sample is new, worn, swollen, compressed, or damaged.

Can I request a quotation using only photographs?

Photographs can support an initial feasibility discussion. Accurate mold and production quotation normally requires enough dimensional and structural information to define the final part.

Should I send the mating component?

Yes, when fit, sealing, stretch, grip, retention, or installation depends on another component. A STEP file, drawing, physical sample, or detailed dimensions of the mating part can help prevent fit problems.

Can Reemane help before the final CAD design is complete?

Yes. Early review can begin with sketches, samples, photographs, basic dimensions, and a description of the intended function. Reemane can identify likely molding risks and explain what information is still required before tooling quotation.

What is the best combination of files for a silicone RFQ?

For a new custom product, the best package is generally a STEP file, controlled 2D drawing, application information, quantity, and mating-part data when relevant. For reverse engineering or failure analysis, also provide the physical sample and assembly photographs.