Cleanroom Production & Full Delivery Inspection Specification For Medical SUS316L Non-magnetic Precision Clinch Nuts & Studs, Based On GB/T 17880

Cleanroom Production & Full Delivery Inspection Specification For Medical SUS316L Non-magnetic Precision Clinch Nuts & Studs, Based On GB/T 17880

MRI and endoscopic medical devices require strictly non-magnetic fasteners. Ordinary SUS316 will be slightly magnetized after processing and interfere with imaging. Low-magnetic SUS316L raw material and full cleanroom control are mandatory. This article sets complete production and inspection rules per GB/T 17880.

1. Magnetic Permeability Standard For Low-magnetic SUS316L Raw Material

Incoming inspection rule: Relative magnetic permeability μr ≤1.01 for medical MRI grade; μr＞1.03 is ordinary SUS316 and cannot be used for MRI equipment; re-test permeability after forming and passivation to avoid processing magnetization.

2. Core Cleanroom Production Control Procedures

1. Static pressing only, high-speed impact stamping forbidden to prevent lattice magnetization; all tooling polished stainless steel without iron debris shedding; 2. Multi-stage ultrasonic degreasing & pure water rinsing, vacuum drying to eliminate residual oil; 3. Chrome-free medical passivation without surface precipitation; 4. Independent vacuum packaging with dust-free desiccant before delivery.

3. Three Mandatory Full Inspection Items Before Delivery

1. Panel flatness: Max protrusion ≤0.05mm after clinching for zero-defect medical appearance; 2. Axial pull-out force: Min 280N for M1.6, min 650N for M3 to pass inspection; 3. Magnetic permeability re-test: Random sampling per batch, over-standard products isolated for demagnetization rework.