Choosing the right steel grade for your tablet dies and punches directly affects tooling life, tablet quality, and production costs. At EMMKAY INDUSTRIES, we manufacture tooling in four steel grades — OHNS, HCHC (D3), S7, and our proprietary EMMKAY Special Steel. After 40+ years of manufacturing in Delhi, we've seen how the right steel choice can double tooling life and eliminate production problems.
Steel Grade Comparison at a Glance
| Grade | Hardness (HRC) | Best For | Wear Resistance | Toughness | Cost |
|---|---|---|---|---|---|
| EMMKAY Special | 55–60 | Budget-friendly, corrosive formulations | Good | Good | Most affordable |
| HCHC (D3) | 62–64 | Dies (standard recommendation) | Excellent | Lower | Moderate |
| OHNS | 58–62 | Punches, general use | Good | Good | Moderate |
| S7 | 56–58 | Deep concave and chipping-prone | Moderate | Excellent | 15–30% premium |
All grades are available across D Tooling, B Tooling, and BB Tooling standards. For a full technical breakdown, visit our steel grades comparison page.
When to Choose Each Steel Grade
Choose OHNS When
- You need punches for non-abrasive formulations — paracetamol, ibuprofen, metformin, or similar APIs
- You manufacture standard pharmaceutical or ayurvedic tablets with herbal ingredients
- Budget is a concern for punches — HCHC (D3) is still recommended for dies
OHNS is a solid choice for punches in non-abrasive applications. For dies, HCHC (D3) is the standard recommendation due to the higher wear dies experience from powder flow.
Choose HCHC (D3)
HCHC (D3) is the standard steel grade for dies. It is also recommended for punches when working with abrasive formulations.
Choose S7 When
- Your punch tips are chipping or breaking with OHNS or HCHC
- You use deep concave tablet designs or tablets with thin walls and sharp edges
- You produce large veterinary bolus tablets (20mm+) with deep cups
- You compress at very high forces where impact resistance matters more than hardness
EMMKAY Special Steel for Corrosive Formulations
For formulations that are corrosive rather than abrasive, none of the three standard grades is optimal. EMMKAY Special Steel (55–60 HRC) is our proprietary corrosion-resistant grade designed for effervescent tablets (citric acid, tartaric acid), Vitamin C tablets, chewable tablets with acidic flavoring, and any formulation causing rust or pitting on standard tooling. Read the complete steel grades comparison.
Tips for Maximizing Tooling Life
- Clean tooling after every batch — remove all powder residue promptly
- Store properly — dry, climate-controlled environment with food-grade oil applied
- Inspect regularly — check punch tips for wear, chipping, or pitting
- Rotate tooling sets — distribute wear evenly across multiple sets
- Never mix steel grades in the same turret
- Consider coatings — TiN for abrasive formulations, DLC for sticky ones. See our coatings guide
For a complete maintenance routine, read our maintenance guide.
Conclusion
HCHC (D3) is the standard for all dies. OHNS works well for punches in non-abrasive applications. S7 solves chipping problems that harder steels cannot handle. And EMMKAY Special Steel is the most affordable option and the answer for corrosive formulations.
Not sure which grade is right for your formulation? Contact EMMKAY INDUSTRIES — we will recommend the best steel based on your specific ingredients and production requirements.