Medical Industry CNC Machining: These Standards Must Be Followed

1. Material Compliance: Dual Compliance with Biocompatibility and Qualifications

• Biocompatibility requirements: Parts in direct contact with the human body (such as artificial joints, surgical forceps) must use materials that comply with ISO 10993 standards—Ti-6Al-4V titanium alloy (corrosion-resistant, good compatibility with human bone tissue) is preferred for orthopedic implants, and 316L stainless steel (carbon content ≤0.03%, reducing metal ion leaching) is commonly used for surgical instruments to avoid allergies or rejection reactions;
• Material qualification traceability: Each batch of raw materials must be accompanied by a "Certificate of Conformity (CoC)" indicating composition, hardness (e.g., titanium alloy HV300±20), heat treatment status, etc. It must also pass third-party testing accredited by SGS or FDA; recycled materials or substitute materials without qualifications are prohibited;
• Prohibited risky materials: Alloys with nickel content exceeding 0.1% (prone to causing allergies) are strictly prohibited in parts that come into contact with blood or tissue, and coating materials without toxicological testing are also not allowed.

2. Process Compliance: Dual Control of Precision and Stability

• Dimensional tolerance requirements: The key dimensional tolerance of orthopedic implants (such as spinal screws) must be controlled within ±0.005mm, and the opening/closing gap of surgical instruments must be ≤0.01mm. Each batch must be sampled and tested using a Coordinate Measuring Machine (CMM), with a pass rate of 100%;
• Process parameter solidification: A "parameter locking" mechanism must be established in the machining process—for example, the cutting speed of titanium alloy implants is fixed at 1000±50r/min, and the feed rate at 0.12±0.01mm/r; random adjustments are strictly prohibited. Parameter records must be retained for each piece of equipment, traceable to specific operators and times;
• Process validation requirements: Process Validation (PV) must be completed before mass production of new parts, involving continuous production of 3 batches (50 pieces per batch). Mass production can only start if all dimensions and surface roughness (required to be below Ra0.4μm to avoid dirt accumulation) are qualified, in line with the "process confirmation" requirements of ISO 13485.

3. Traceability Compliance: Full Traceability from Raw Materials to Finished Products

• Level 1 traceability (materials): The raw material batch number is bound to the unique part code; scanning the code allows checking of the material supplier, CoC number, and test report;
• Level 2 traceability (machining): Record the equipment number, machining time, operator, and key parameters (such as cutting force, cooling temperature) of each CNC process. If dimensional deviations occur, the problematic process can be accurately located;
• Level 3 traceability (testing): The CMM test data and surface treatment report (such as the salt spray test result of passivation treatment) of each product must be archived, with a retention period of no less than the product's full life cycle (usually 5-10 years).

4. Cleaning and Sterility Compliance: Avoiding Microbial and Particle Contamination

• Residue control: After machining, oil stains and cutting chips must be removed using medical-grade cleaning agents (such as neutral multi-enzyme cleaners). The oil residue on the part surface must be ≤5μg/cm², and particle contamination must meet the Class 8 cleanroom requirements of ISO 14644-1 (number of particles ≥0.5μm per cubic meter ≤352,000);
• Sterilization treatment: Implantable parts must undergo gamma ray sterilization (dose 25-50 kGy) or EO sterilization. A sterility report must be issued after sterilization, and the sterility validity period must be marked (usually 2-3 years);
• Packaging compliance: Sterilized parts must be packaged in medical-grade sterile packaging (such as Tyvek paper + PET film). The packaging must be marked with the sterilization batch, validity period, and unique traceability code to avoid secondary contamination during transportation.

Why Are These Standards Indispensable?