When an RFQ reaches our engineering team at ECO POLYMER, the drawing is only one part of the story. A catheter tube can look fully defined in CAD while still leaving major questions about its function, mating parts, material grade, performance targets, inspection method, and expected production scale. Those open points slow quotation because they change tooling, process control, testing, and cost.

This guide follows the sequence we use to turn an early request into a manufacturable specification: start with function, define the CTQs, connect material and geometry to performance, agree on verification, and then add the commercial plan. You can also download our editable Excel checklist and use it to compare potential suppliers.

What Information Should You Include in a Custom Catheter Tubing RFQ?

A strong RFQ gives the supplier enough information to evaluate feasibility, tooling, material, inspection, lead time, and scale-up risk. It does not need every answer to be final. It does need to show which inputs are controlled, which are targets, and which require joint engineering work.

RFQ Requirements at a Glance

Prefer to work offline? Download the editable catheter tubing RFQ checklist.

What Should You Tell the Supplier About the Catheter Application?

The first engineering question is not “What is the OD?” It is “What does this tube need to do inside the finished device?” Application context helps us understand which specifications drive function and which dimensions are simply references.

Device Function and Clinical Use

State whether the tube supports fluid delivery, aspiration, guidewire movement, balloon inflation, sensor routing, electrical conductors, steering elements, or another task. Include relevant use conditions such as temperature, pressure, exposure duration, chemical contact, or anatomical access. The tubing supplier does not determine the final device's clinical suitability, but this context is essential for engineering review.

Mating Components and Assembly Processes

Show the guidewire, connector, hub, shaft segment, liner, braid, coil, or other parts that interface with the tube. Also identify bonding, welding, reflow, tipping, flaring, drilling, printing, coating, or thermal forming operations. A material that extrudes well may still be a poor choice if it does not bond reliably or cannot tolerate the customer's downstream process.

Which Tubing Dimensions and Tolerances Should Be Specified?

At minimum, specify OD, ID, wall thickness, length, and the tolerance basis. For a detailed explanation of how these values interact, see our guide to catheter tubing dimensions and tolerances.

OD, ID, and Wall Thickness

OD controls profile and external fit. It may affect passage through a device, compatibility with a hub, or the finished catheter profile. ID controls clearance and flow area. It may be linked to a guidewire, tool, fluid path, or pressure-drop target. Wall thickness influences flexibility, kink behavior, strength, and burst performance. These dimensions should be reviewed as a system because changing one can constrain the others.

Multi-Lumen Geometry and Web Thickness

A multi-lumen RFQ should show the number, size, shape, and angular orientation of each lumen. Identify any main lumen, satellite lumen, D-shaped lumen, oval lumen, or non-symmetrical feature. Define minimum web thickness where the material between lumens protects separation, pressure performance, or structural stability.

Annotated Multi-Lumen RFQ Drawing Example

The example below shows the minimum relationships we want to see in a controlled multi-lumen drawing: OD, lumen ID, web thickness, clocking, material, tolerance, and length. The values are illustrative and must be replaced with project-specific requirements.

Critical vs Non-Critical Tolerances

Do not apply the tightest available tolerance to every dimension. First identify the dimensions that directly control safety, function, fit, or assembly. Mark these as CTQs and explain their acceptance basis. Reference dimensions can remain less restrictive.

How Should You Specify the Catheter Tubing Material?

Writing only “Pebax,” “nylon,” or “polyurethane” is usually incomplete. A polymer family can include grades with very different hardness, melt behavior, additives, bondability, and documentation. Use our catheter tubing material selection guide to connect the resin decision to device requirements.

Polymer and Grade

Specify the exact grade or identify the acceptable performance window and ask for supplier input. Include approved manufacturers or sources, if controlled. When substitution is restricted, state the change-control requirement. Material family is a starting point; grade and supply control make the requirement actionable.

Hardness and Mechanical Requirements

Hardness is useful, but it is not a complete shaft specification. A durometer target should be linked to bending stiffness, pushability, trackability, kink recovery, torque transmission, or another measurable function. Geometry, wall distribution, reinforcement, and processing history also influence mechanical performance.

Color, Radiopacity, and Additives

Define color or opacity with an approved standard or sample when appearance is controlled. For radiopaque tubing, state the target additive, loading range if known, and the required imaging performance or test basis. Also identify lubricity, UV stability, antimicrobial, filler, or restricted-substance requirements. Additives can change both extrusion behavior and finished-part performance.

Which Construction Details Should Be Defined?

Which Performance Requirements Should Be Included in the RFQ?

This is where an RFQ becomes a functional specification. The supplier should understand what must be achieved, how it will be measured, under which conditions, and what result is acceptable.

Flexibility, Kink Resistance, and Torque

For flexibility, define a bending stiffness method or a comparative target. For kink resistance, specify bend radius, fixture, conditioning, and pass/fail criteria. For torque, identify rotation input, output, unsupported length, and acceptable lag or loss. Words such as “soft,” “good kink resistance,” or “high torque” are too subjective for release criteria.

Burst, Tensile, and Flow Requirements

State the working and proof or burst pressure, medium, temperature, ramp rate, dwell time, and failure definition. For tensile or pull force, define grip arrangement and gauge length. For flow, include fluid, pressure differential, temperature, and required minimum flow or maximum pressure drop.

Bonding and Sterilization Compatibility

Identify the adhesive, solvent, welding, reflow, or thermal process used in assembly and the required joint strength. Name the intended sterilization method and number of cycles. The final compatibility decision belongs to the device manufacturer and its validation program, but the tubing supplier needs these conditions to assess material and process risk.

What Testing and Inspection Requirements Should You Define?

Dimensional Inspection

Identify which dimensions require routine inspection, the proposed measurement method, sampling plan, and reporting frequency. Complex lumen geometry may require cross-section preparation, optical measurement, or other specialized methods. The inspection approach must be capable of resolving the tolerance.

Functional Testing

For kink, burst, tensile, torque, flow, bonding, or sterilization-related tests, state the protocol or define who will create it. Also clarify whether testing is performed by the supplier, customer, or an external laboratory. Undefined test ownership is a common source of schedule delay.

Inspection Reports and Traceability

List the documents expected with samples, validation lots, and production shipments. These may include first article inspection, dimensional data, certificate of analysis, certificate of conformance, material certificates, test reports, lot identification, and raw-material traceability. Match reporting depth to risk and project stage instead of requesting every record for every shipment by default.

What Quality and Regulatory Information Should Be Requested?

Supplier qualification should distinguish between the tubing supplier's quality system, the component specification, and the finished medical device manufacturer's regulatory responsibilities. Avoid vague statements such as “FDA-certified tubing.” Ask for the specific system, material, process, documentation, and change controls your program requires.

Quality Management System

For U.S.-market medical device programs, use current terminology. The FDA Quality Management System Regulation, or QMSR, became effective on February 2, 2026, and the revised 21 CFR Part 820 incorporates ISO 13485:2016 by reference. ISO describes ISO 13485 as the internationally recognized QMS standard for medical device design and manufacture. Determine which requirements apply to the legal manufacturer and which supplier controls must flow down to the component level.

References: FDA QMSR and ISO 13485:2016.

Material and Lot Documentation

Define approved resin grades and sources, required certificates, restricted-substance declarations, material identification, lot traceability, and any customer-specific documentation. If biocompatibility information is requested, clarify what evidence the supplier can provide and what testing remains the device manufacturer's responsibility.

Change Control and Traceability

State the required notification period and approval path for changes that may affect material, source, tooling, process, inspection method, manufacturing location, or specification. Define lot and raw-material traceability expectations, record-retention time, and labeling content.

What Project and Volume Information Does the Supplier Need?

Prototype Quantity

Give the quantity, required lengths, and intended use of the prototype lot. A feasibility sample, bench-test lot, design verification lot, and process validation lot may need different controls and documentation. This context helps the supplier propose the right development route.

Annual Forecast

Even if the forecast is preliminary, provide a realistic range. Annual volume and peak demand influence tooling, line selection, inspection automation, packaging, MOQ, capacity, and cost. Prototype quantity without a production forecast gives an incomplete commercial picture.

Sample and Launch Timeline

List the requested quotation date, drawing freeze, prototype need date, validation build, production launch, and expected lead time. Flag any fixed clinical, regulatory, or customer milestones. A supplier can only assess acceleration options when the full sequence is visible.

What Should You Include in Your Catheter Tubing Drawing?

Critical Dimensions

Include units, datums or measurement references, OD, ID, wall, length, transitions, and CTQs. State whether dimensions apply in a free state, under a specified fixture, or after conditioning. Avoid duplicate or mathematically conflicting dimensions.

Lumen Orientation

Use clocking, centerlines, angles, section views, and clear lumen identifiers. If orientation to a stripe, marker, braid feature, distal shape, or connector matters, show that relationship. Define the allowable angular tolerance only as tightly as function requires.

Notes, Materials, and Inspection Criteria

Include the drawing revision, material and grade, color and additives, general tolerances, surface criteria, packaging notes, applicable specifications, and inspection requirements. If a performance requirement is too detailed for the drawing, reference a controlled specification or test protocol.

Which RFQ Mistakes Can Increase Cost or Delay Development?

How Should You Evaluate a Custom Catheter Tubing Supplier?

A low unit price does not compensate for a process that cannot hold the geometry, verify CTQs, or scale. When comparing a custom catheter tubing manufacturer, score both the quoted part and the evidence behind the proposal.

Extrusion and Tooling Capability

Ask whether the supplier can manufacture the lumen count, shapes, transitions, material combinations, and tolerance scheme. Review the proposed tooling and development plan. Useful DFM feedback should identify risks, explain trade-offs, and separate confirmed capability from items that still need trials.

Inspection and Process Control

Confirm how CTQs will be measured, what sampling is proposed, how gauges or measurement systems are qualified, and which process characteristics are monitored. For multi-lumen tubing, ask how cross-section shape, orientation, web thickness, and lumen integrity are verified.

Prototype-to-Production Scalability

Ask whether the prototype method represents the intended production process. Compare tooling, line, inspection, handling, packaging, and documentation across prototype, validation, and routine production stages. A good scale-up plan makes changes visible before validation.

Engineering Support

Evaluate how the supplier handles unclear requirements, design iterations, material alternatives, test development, documentation, and change communication. Early engineering collaboration is especially important when the profile combines small OD, multiple lumens, thin webs, reinforcement, or demanding downstream assembly.

How Can You Prepare a Complete RFQ Before Contacting a Supplier?

Final RFQ Checklist

Documents to Attach

Attach the controlled drawing or CAD, performance specification, material or regulatory requirements, quality requirements, forecast, timeline, and any interface drawings or test protocols. Use filenames and revisions that can be traced to the RFQ.

Information the Supplier Can Help Define

You do not need to invent every value before contacting a supplier. Mark uncertain items as “Needs Supplier Input” and explain the functional target. ECO POLYMER can use DFM review to discuss geometry, material options, tolerance priorities, construction, and verification strategy. Final device requirements and validation decisions remain with the customer.