Buyer Guide: How to RFQ Braided & Coil Reinforced Catheter Shafts

When a reinforced catheter concept moves from benchtop to pilot production, the RFQ phase is often where timelines slow down. Vague performance requirements, missing specs, or unaligned validation expectations can create quoting loops, inaccurate pricing, and delayed project launches.

Here are the practical checkpoints and dimensional realities to define before you send that RFQ email to an OEM partner.

1. Define the Core Architecture and Materials

Before any quoting begins, establish the fundamental stackup of your catheter shaft. A simple "we need a braided catheter" is insufficient. Specify:

• Inner Liner: Is it an etched PTFE liner? What is the required inner diameter (ID) and wall thickness? OEM standard limits: PTFE wall thicknesses often range from 0.0005" to 0.003". (See our guide on avoiding PTFE reflow defects for critical tolerances).
• Reinforcement Layer: Are you using stainless steel braid (e.g., 304V), nitinol coil, or a hybrid structure? (Read our Braid vs. Coil architecture breakdown).
  • For braids, define the wire dimensions (e.g., 0.001" x 0.003" flat wire), braid angle, and PIC (picks per inch).
  • For coils, define the pitch (e.g., zero gap vs. 0.002" gap).
• Outer Jacket: What polymer are you using? (e.g., Pebax 35D to 72D, Vestamid Nylon 12, or Polyurethane). What are the durometer zones along the length of the shaft?

Material Quick Reference Matrix

2. Outline Transition Zones and Distal Assembly

Most high-performance catheters are not uniform from hub to tip. Ensure your RFQ calls out:

• Durometer Transitions: Location and length of flexibility transitions (e.g., stiff 72D proximal section transitioning to a 35D floppy distal tip).
• Marker Bands: Placement and assembly method (swaging vs. reflow encapsulation) for radiopaque marker bands. (See our Marker Band Assembly Guide).
• Tip Forming: Do you require an atraumatic soft tip? Is it butt-welded or continuous reflow?

3. Establish Validation and CTQ Requirements

A manufacturer needs to know how you will measure success to quote the correct Quality Control (QC) overhead:

• Critical-to-Quality (CTQ) Dimensions: What are the strict tolerances for OD, ID, and concentricity? Note: Requesting ±0.0005" on an extruded jacket will significantly increase scrap rates and cost compared to a standard ±0.001".
• Performance Targets: Specify minimum kink radius, torque transmission percentage (e.g., 1:1 rotation), or tensile pull strength for the hub bond.
• Documentation: Will you require full First Article Inspection (FAI) reports, material certifications, or specific ISO 13485 traceability packages (e.g., complete DHR)?

4. Minimum RFQ Template for Faster Responses

For the fastest, most accurate quoting process with an OEM, ensure your initial email covers:

1. Product Scope: (e.g., Braided Shaft, Coil Reinforced, PTFE Lined)
2. Target Dimensions: OD / ID / Usable Length / Tolerances
3. Reinforcement Specs: Wire material, geometry (flat vs round), and density (PPI/Pitch)
4. Jacket Specs: Polymer type and durometer layout
5. Volume: Prototype Quantity (e.g., 50 pcs) vs. Annual Forecast (e.g., 10,000 pcs)
6. Timeline: Expected delivery date for First Articles

Get a Quote That Actually Means Something

If you have your specifications ready, or if you need an honest Design for Manufacturability (DFM) check before freezing your tolerances, send your prints to [email protected]. Our engineering team will review it and help you avoid the common manufacturing traps.