The Problem: Surface Scratches & Clamping Marks
During CNC turning of precision shafts (as shown in Figure 1), surface damage often occurs due to:
- Metal-to-metal contact with traditional fixtures
- Excessive clamping pressure
- Abrasion during rotation
These imperfections compromise part quality and increase rejection rates.
SPierson's Proven Solution: Nylon Protective Fixtures
Our engineered nylon fixtures (Figure 2) eliminate surface damage through:
✔ Non-Marring Contact
- Softer than workpiece material (60-70 Shore D)
- Eliminates tooling marks
- Preserves surface finish
✔ Optimized Pressure Distribution
- Evenly distributes clamping forces
- Prevents localized deformation
- Maintains dimensional accuracy
✔ Enhanced Process Stability
- Anti-slip textured surface
- Withstands machining vibrations
- Reusable up to 5,000 cycles
Technical Benefits
- Surface roughness maintained at Ra 0.4μm or better
- 100% elimination of visible clamping marks
- No additional finishing operations required
- Compatible with all common shaft materials
Implementation Case Study
For a German automotive client producing 10,000 transmission shafts/month:
- Reduced surface rejection rate from 12% to 0.3%
- Saved €28,000/month in rework costs
- Improved cycle time by eliminating secondary polishing