The steel grade of your tablet dies and punches directly affects tooling life, tablet quality, and production costs. Different formulations require different steel properties — abrasive powders need harder steel, while corrosive formulations need corrosion-resistant grades.
EMMKAY INDUSTRIES manufactures tablet dies and punches in four steel grades, each designed for specific production requirements.
Steel Grade Comparison
| Grade | Hardness | Wear | Toughness | Corrosion | Cost |
|---|---|---|---|---|---|
| EMMKAY Special | 55-60 HRC | Good | Good | Excellent | Most affordable |
| HCHC (D3) | 62-64 HRC | Excellent | Lower | Good | Moderate |
| OHNS | 58-62 HRC | Good | Good | Moderate | Moderate |
| S7 | 56-58 HRC | Moderate | Excellent | Moderate | Similar to HCHC |
OHNS — Standard Steel (Most Common)
Oil Hardening Non-Shrinking steel. Hardness: 58-62 HRC. The default choice for approximately 70% of tablet manufacturing applications.
When to choose OHNS:
- ·Standard pharmaceutical tablets (paracetamol, ibuprofen, metformin)
- ·Nutraceutical tablets (herbal extracts, basic vitamins)
- ·Ayurvedic formulations
- ·When cost-effectiveness is a priority
HCHC (D3) — Standard for Dies
High Carbon High Chromium steel (D3 tool steel). Hardness: 62-64 HRC. The standard recommendation for all die bores due to superior wear resistance — dies experience more abrasion than punches.
When to choose HCHC:
- ·All die bores — standard recommendation for dies
- ·Abrasive formulations (calcium, iron, minerals) — for both dies and punches
- ·Mineral-based nutraceutical tablets
- ·When maximum tooling life is the priority
S7 — Impact-Resistant Steel
Shock-resistant tool steel. Hardness: 56-58 HRC. Highest impact resistance of any grade — absorbs energy better than OHNS or HCHC.
When to choose S7:
- ·Deep concave or cup-shaped tablet designs
- ·Formulations that cause punch tip chipping
- ·High compression force applications
- ·Large tablets (20mm+) with thin walls
EMMKAY Special Steel — Corrosion-Resistant
Proprietary corrosion-resistant tool steel. Hardness: 55-60 HRC. Developed specifically for the challenges of corrosive formulations.
When to choose EMMKAY Special Steel:
- ·Manufacturing environments with high humidity
- ·When rust and pitting are recurring problems on standard tooling
- ·Budget-conscious manufacturers looking for the most affordable option
Quick Selection Guide
| Your Situation | Recommended | Why |
|---|---|---|
| Standard pharma tablets | OHNS | Good all-round for punches |
| Dies (all formulations) | HCHC (D3) | Standard recommendation for dies |
| Calcium or mineral tablets | HCHC (D3) | Hardest — resists abrasive wear |
| Iron supplement tablets | HCHC (D3) | Maximum wear resistance |
| Deep concave designs | S7 | Impact-resistant, prevents chipping |
| Punch tips keep chipping | S7 | Absorbs impact energy |
| Effervescent tablets | S7 or HCHC | Toughness or wear resistance |
| Vitamin C tablets | HCHC (D3) | Resists acid and abrasion |
| High humidity factory | EMMKAY Special | Prevents rust and pitting |
| Budget-conscious | EMMKAY Special | Most affordable option |
Frequently Asked Questions
Can I mix steel grades in the same turret?
No. All dies and punches on a turret should be the same steel grade and hardness to ensure uniform compression and consistent tablet quality.
How much longer does HCHC last compared to OHNS?
For abrasive formulations, HCHC typically lasts 30-50% longer than OHNS. For non-abrasive formulations, the difference is smaller and OHNS is usually the better value. Read our tooling lifespan guide.
Is EMMKAY Special Steel available for all shapes?
Yes. All four steel grades are available for every tablet shape — round, capsule, oval, custom designs, and multi-tip.