Metallurgically bonded, not welded
The hard region is bonded during pouring, so there is no weld interface to fail under shredder impact.
Shredder Wear Parts
Dual Hardness Shredder Hammers
Hammers with a hardened striking face over a tough body, for longer face life without giving up impact resistance.
Overview
About dual hardness shredder hammers
A conventional manganese hammer is tough everywhere but relies entirely on work-hardening for its wear face. A dual hardness hammer starts with a genuinely hard striking region backed by a tough, ductile body, so the face resists abrasion from the first hour while the eye and shank keep their impact resistance.
Melco produces dual hardness hammers as a bi-metallic casting: the hard wear region is metallurgically bonded to the tougher body during pouring, not welded on afterwards. That bond is what keeps the hard region attached under shredder loading.
The result suits operations where hammers are being pulled for face wear rather than for breakage, which is the case in many automobile shredders running relatively clean, dense scrap.
Applications
- Automobile and ELV shredders on dense scrap
- High-throughput scrap recycling lines
- Operations replacing hammers on face wear rather than breakage
- Shredders where hammer change-out downtime is costly
Features
What you get
Hard face from hour one
The striking region does not wait for work-hardening to reach its working hardness.
Tough body retained
Eye and shank stay ductile, so the hammer survives the shock loads that break fully hard castings.
Fewer change-outs
Longer face life targets the real cost in a shredder: the downtime of a hammer change, not the hammer itself.
Specifications
Manufacturing specification
Applies to dual hardness shredder hammers produced at our works. Castings outside this range can usually be accommodated, so please ask.
| Moulding | No-bake resin sand and green sand |
|---|---|
| Melting | Induction furnace, spectrometer-controlled |
| Piece weight | 5 kg – 2,000 kg |
| Heat treatment | In-house, computer-controlled cycles |
| Dimensional control | Template and CMM check against drawing |
| Documentation | Chemical, hardness and dimensional report per heat |
Material grades
| Grade | Typical composition | Hardness | Suited to |
|---|---|---|---|
| Dual hardness (hard face) | Alloyed white iron / martensitic wear region | 55–62 HRC | Striking face |
| Dual hardness (body) | Austenitic manganese steel, ASTM A128 | 200–229 BHN, work-hardening | Eye, shank and body |
| ASTM A128 Grade A | 1.05–1.35% C, 11.0–14.0% Mn | 200–229 BHN as-cast, 500+ BHN work-hardened | Standard high-impact duty |
| ASTM A128 Grade B-3 | 0.9–1.05% C, 11.5–14.0% Mn | 200–229 BHN as-cast, 500+ BHN work-hardened | Heavier sections, improved toughness |
Composition ranges are quoted against the published standard. Actual analysis for your heat is issued with the castings.
Gallery
From our works
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Dual hardness hammers: hard face bonded to a tough manganese body. -
Export packing: palletised, strapped and heat-number marked. -
Manganese hammers after solution annealing and water quench.
Questions
Dual Hardness Shredder Hammers: common questions
How is a dual hardness hammer different from a hardfaced one?
A hardfaced hammer has wear-resistant weld deposited on the surface after casting, and that deposit can spall off at the weld interface under shredder impact. A dual hardness hammer is bi-metallic from the pour, so the hard region and the tough body share a metallurgical bond rather than a weld line.
When is a dual hardness hammer worth the extra cost?
When you are pulling hammers because the face has worn away rather than because they have cracked or broken. If breakage is your failure mode, a straight manganese hammer is usually the better answer.
Can dual hardness hammers be turned like standard ones?
It depends on the design. Symmetrical dual hardness hammers with hard regions on both striking faces can be turned; single-face designs cannot. We will tell you which you are ordering.
Do they work in the same rotor as our current hammers?
Yes, provided the weight and eye dimensions match. We cast to your existing hammer geometry and weight-match the set so rotor balance is unaffected.
More from our range
Related products
Enquiry
Enquire about dual hardness shredder hammers
Tell us the machine, the feed and the quantity. If you have a drawing or photographs of the worn part, mention it and we will send an upload link.
Melco Castings is an independent manufacturer of replacement wear parts. Machine and OEM names are used only to identify the equipment our castings fit. We are not affiliated with, endorsed by, or a distributor for any of these manufacturers.