How to Qualify a Rubber Parts Supplier: 10-Point Audit Checklist

Why Supplier Qualification Matters

A poor rubber parts supplier can cost you far more than the price difference on the parts. Equipment failures, production delays, customer returns, and reputation damage are real risks. This 10-point checklist helps you qualify suppliers before you commit.

The 10-Point Supplier Qualification Checklist

1. Quality Management System

• ISO 9001 certified (minimum standard)
• IATF 16949 for automotive applications
• ISO 13485 for medical rubber parts
• Check certificate validity — is it current or expired?

2. Manufacturing Capability

• Own mold manufacturing capability (vs. outsourcing)?
• What processes do they offer: compression, injection, LSR, transfer?
• Part size range and hardness range available
• Annual production capacity — can they handle your volume?

3. Material Sourcing & Traceability

• Where do they source raw materials (brand names: Viton®, Dow, Wacker)?
• Can they provide material data sheets (TDS) and compliance certificates?
• Full batch traceability from raw material to finished part?

4. Incoming & In-Process Inspection

• CMM (coordinate measuring machine) available?
• Hardness testing (Shore A durometer)?
• Visual inspection protocol?
• Is there a documented inspection plan per part type?

5. First Article Inspection (FAI)

• Do they perform FAI on every new part or mold change?
• Is the FAI report comprehensive: dimensions, appearance, hardness, material?
• Is the FAI report signed off by QC and engineering?

6. Communication & Responsiveness

• Response time to emails (within 24 hours is a good benchmark)
• Is there a dedicated engineer or account manager for your account?
• Do they proactively flag quality issues or delays?
• English proficiency — can they read your technical drawings?

7. Problem Resolution Process

• Do they have a documented 8D or CAPA (Corrective Action) process?
• Can they provide containment, root cause analysis, and corrective action for quality issues?
• What is their typical response time for urgent quality concerns?

8. Environmental & Safety Compliance

• ISO 14001 environmental management?
• RoHS / REACH compliance documentation?
• No child labor, safe working conditions (social compliance)?

9. Financial Stability & Longevity

• How long has the company been in business?
• Do they serve stable, referenceable customers?
• Any signs of financial stress that could affect your orders?

10. Visit or Virtual Audit

• Request a factory visit (in-person or virtual)
• Observe: is the factory clean, organized, with clear work instructions?
• Check: are machines well-maintained with maintenance logs?
• Review: quality documentation, training records, and equipment calibration logs

Red Flags to Watch Out For

• Cannot provide material certificates for their compounds
• No inspection equipment or only rely on visual inspection
• Refuses to share references or customer list
• Promises unrealistic lead times (e.g., 3 days for a new mold)
• No quality management documentation or SOPs visible
• Unwilling to accept third-party inspection or testing

Anlintech welcomes supplier audits and can provide full quality documentation including material certificates, inspection reports, and process capability data. Request a supplier qualification package.