Background
A precision-gearing supplier wanted to extend the life of its ASP 2052 multistart re-sharpened gear-hob cutter on a Liebherr LC-300 6-axis CNC hobbing machine. Despite a premium AlCrN PVD coating, the tool consistently capped out at 840 parts when cutting SAE 8620 automotive gears.
Cryogenic Solution
The hob underwent a tailored deep-cryogenic cycle (-185 °C soak, gradual warm-up, post-temper). No geometry or coating changes were made—only the steel’s microstructure was refined.
Quantified Results
| Metric | Pre-Cryogenic | Post-Cryogenic | Improvement |
|---|---|---|---|
| Components per re-sharpen | 840 | 1 546 | +84 % |
| Tool-life multiplier | 1.00× | 1.84× | – |
Additional Benefits
- Improved surface finish on finished gears.
- Grinding allowance reduced by 0.020 mm during subsequent shaving operations.
- More stable wear pattern, making tool life predictable.
- Lower heat input during cutting, reducing distortion risk in later hardening steps.
Takeaway
Integrating deep-cryogenic treatment boosted tool productivity by 84 % with no hardware changes. The added gains—smoother gear surfaces and a 0.020 mm leaner grinding allowance—cut downstream finishing time and tooling costs, proving cryogenics a fast, cap-ex-free lever for competitive edge in gear production.