ENGINEERING GUIDE
Industrial Crusher and Shredder Blades: DIN 1.2379 (D2) Tool Steel, Heat Treatment & Wear Guide
Shredder and crusher blades in DIN 1.2379 (D2) steel: vacuum heat treatment, hardness, wear and how to choose and resharpen blades.
In plastic recycling, automotive shredding, e-waste processing and heavy scrap lines, the single largest operational cost and unplanned downtime source is blade wear, cutting edge chipping, and clearance degradation.
Standard structural steels (St52, C45) deform rapidly under heavy loads and high RPMs. This leads not only to frequent replacement costs, but also material jamming, excessive heat generation, motor overloads, and high dust content in finished granules.
In this technical guide by OSEL Makine, we analyze tool steel metallurgy, vacuum heat treatment standards, and micron-level grinding tolerances for heavy-duty granulator and shredder blades.
1. Tool Steel Selection: DIN 1.2379 (D2) vs DIN 1.2344 (H13)
60% of blade performance depends on raw material metallurgy. Carbon and chromium ratios govern abrasion resistance and core toughness against foreign metallic ingress.
| Specification | DIN 1.2379 (AISI D2) | DIN 1.2344 (AISI H13) | DIN 1.2360 (Chipper) |
|---|---|---|---|
| Carbon (C) | ~1.50 - 1.60% | ~0.35 - 0.42% | ~0.50 - 0.55% |
| Chromium (Cr) | ~11.50 - 12.00% | ~4.80 - 5.50% | ~8.00 - 8.50% |
| Typical Hardness | 58 - 60 HRC | 52 - 55 HRC | 54 - 57 HRC |
| Wear Resistance | ⭐⭐⭐⭐⭐ (Maximum) | ⭐⭐⭐ (Medium) | ⭐⭐⭐⭐ (High) |
| Impact Toughness | ⭐⭐⭐ (Balanced) | ⭐⭐⭐⭐⭐ (Ultra Tough) | ⭐⭐⭐⭐ (High) |
| Primary Application | PET, PE, PP film & regrind | Thick blocks, tires, scrap | Wood chipping, profiles |
2. Vacuum Heat Treatment & Cryogenic Processing
Atmospheric furnaces cause surface decarburization. At OSEL Makine:
- Vacuum Hardening: Parts are uniformly heated up to 1050°C in oxygen-free vacuum chambers.
- Multi-Stage Tempering: 3-stage tempering relieves internal stress while securing 58-60 HRC.
- Sub-Zero Cryogenics (-120°C): Transforms residual austenite into martensite, boosting wear life by 35%.
3. Micron Precision and Clearance Tolerances
Blades must fit with extreme rigidity. For thin films, cutting clearance is set to 0.10 - 0.15 mm; for thick sections, 0.25 - 0.35 mm. CNC surface grinding guarantees flat mounting surfaces within ±0.005 mm.
4. Dynamic Balancing & Weight Tolerances
Rotors run at 400-800 RPM. Paired blades must weigh within ±2 grams of each other to protect bearings and avoid frame vibrations. Every blade manufactured by OSEL Makine is stamped with batch serials and matched by weight.
Contact OSEL Makine for Custom Crusher & Shredder Blades
Do not wait weeks for expensive European imports. Send us your drawings or sample knives for fast, certified DIN 1.2379 manufacturing in Dilovasi / Kocaeli.
- Facility: KOBI OSB, 41st St. No: 8/2, Dilovasi / Kocaeli, Turkey
- Engineering Phone: +90 262 606 02 75 / WhatsApp: +90 535 764 03 69
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A technical drawing, a sample photo or a short description is enough. We clarify sequence, scope and lead time with the quote.