MIM molds are hardened steel tools that wear over time. Knowing the expected mold life is essential for tooling cost amortization and production planning.
Mold life by steel type and material:| Mold Steel | MIM Material | Typical Life (shots) | Failure Mode |
|---|---|---|---|
| H13 (48-52 HRC) | 316L | 500k-1.5M | Gate erosion, cavity surface wear at high-velocity regions |
| H13 (48-52 HRC) | 17-4PH | 400k-1M | Similar to 316L but accelerated by 17-4PH's abrasiveness |
| H13 (48-52 HRC) | Fe-2Ni | 800k-2M | Less abrasive than stainless — longer life |
| S136 (48-52 HRC) | 316L (POM binder) | 300k-800k | Corrosion + wear; core pins are first to fail |
| NAK80 (37-43 HRC) | 316L | 200k-500k | Surface wear — not suitable for high-volume |
| H13 + PVD coating | 316L | 1M-2M+ | Coating protects against gate wear and corrosion |
- Abrasive materials (titanium feedstock, W-Cu — hard particles accelerate wear)
- High injection pressure (>150 MPa) — erodes gate and runner surfaces
- POM-based binders with catalytic debinding — nitric acid residues corrode unprotected steel
- Thin core pins (under 1 mm diameter) — thermal fatigue fracture
- Poor mold temperature control — thermal cycling accelerates crack formation
For standard 316L in an H13 tool steel mold: expect 500k-1.5M shots before significant wear requires cavity refurbishment or replacement. Core pins wear faster and typically need replacement every 200k-400k shots.
Cost planning rule of thumb: Budget 10-15% of the initial tooling cost per year for mold maintenance and consumable components (core pins, gate inserts). For a $15,000 mold, plan $1,500-2,250/year in maintenance after the first year of production.