Guide to Surface Coating Technologies for Tooling
Surface coatings significantly enhance tool performance by increasing hardness, reducing friction, and improving wear resistance. GS Machining offers a comprehensive range of standard surface treatments to maximize your tooling investment.
Coating Comparison Table
| Coating | Color | Hardness (HV) | Max Temp (°C) | Friction Coefficient | Thickness (μm) |
|---|---|---|---|---|---|
| TiN (Titanium Nitride) | Gold | 2,000–2,400 | 600 | 0.4–0.6 | 1–5 |
| TiCN (Titanium Carbonitride) | Gray-Blue | 2,800–3,200 | 450 | 0.3–0.4 | 1–5 |
| CrN (Chromium Nitride) | Silver | 1,800–2,200 | 700 | 0.3–0.5 | 2–8 |
| AlTiN (Aluminum Titanium Nitride) | Dark Gray | 3,000–3,500 | 900 | 0.4–0.6 | 1–4 |
| DLC (Diamond-Like Carbon) | Black | 1,500–4,000 | 350 | 0.1–0.2 | 0.5–3 |
| TiAlN (Titanium Aluminum Nitride) | Purple-Black | 2,800–3,300 | 800 | 0.4–0.5 | 1–4 |
| Nitriding (Gas) | Gray | 600–1,200 | 500 | 0.6–0.8 | 100–500 |
| Vanadium Carbide | Silver | 2,800–3,200 | 500 | 0.3–0.4 | 5–15 |
Coating Selection by Application
TiN (Titanium Nitride)
- Best for: General purpose punching, forming, injection mold components
- Advantages: Excellent adhesion, good oxidation resistance, easy re-coating
- Not ideal: High temperature applications (>600°C)
TiCN (Titanium Carbonitride)
- Best for: High speed steel tools, tapping, drilling, fine blanking
- Advantages: Higher hardness than TiN, excellent abrasion resistance
- Not ideal: High temperature forming operations
CrN (Chromium Nitride)
- Best for: Die casting, extrusion, plastic molding, adhesive wear prevention
- Advantages: Excellent corrosion resistance, good for non-ferrous metals
- Not ideal: High wear stamping applications
AlTiN / TiAlN
- Best for: High speed machining, hot forming, dry cutting operations
- Advantages: Exceptional heat resistance, oxidation barrier properties
- Not ideal: Low temperature, high adhesion scenarios
DLC (Diamond-Like Carbon)
- Best for: Precision sliding components, ejector pins, medical applications
- Advantages: Extremely low friction coefficient, excellent release properties
- Not ideal: High impact applications — coating can chip
Nitriding
- Best for: Large components, complex geometries, internal features
- Advantages: Full coverage including holes, no dimensional growth issues, low cost
- Not ideal: Where maximum surface hardness is required
Key Coating Benefits
-
Extended Tool Life: 2–10x improvement depending on coating and application
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Increased Production Speed: Higher operating temperatures and speeds possible
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Improved Surface Finish: Reduced galling and material pickup on workpiece
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Reduced Lubrication: Some coatings enable semi-dry or dry operations
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Corrosion Protection: CrN and TiN provide excellent atmospheric corrosion resistance
Coating Combination Strategies
For demanding applications, consider layered approaches:
- DLC over TiN: Excellent wear resistance + low friction
- TiCN + DLC: Maximum hardness + low coefficient of friction
- Nitriding base + PVD topcoat: Diffusion layer support + surface hardness
GS Machining can provide technical consultation to select the optimal coating for your specific application. Contact us to discuss coating options and request sample evaluation.
Browse Our Related Articles
Coatings perform best when paired with the right base material. Explore our Tool Steel Selection Guide and Tungsten Carbide Grade Selection to choose the optimal substrate for your coating. Visit our Manufacturing Facility page to learn about our in-house finishing capabilities.
GS Machining can provide technical consultation to select the optimal coating for your specific application. Contact us to discuss coating options and request sample evaluation.