Work-hardens in service
The struck face climbs past 500 BHN while the body stays tough, so the bar resists cracking rather than resisting only wear.
Crusher Wear Parts
Manganese Steel Blow Bars
Austenitic Hadfield steel bars that work-harden in service. The tough choice for shock loading and tramp metal.
Overview
About manganese steel blow bars
Austenitic manganese steel, known as Hadfield steel, leaves the foundry relatively soft at around 220 BHN and hardens to over 500 BHN at the working surface as it is struck. The core stays tough and ductile, which is why a manganese bar bends and deforms where a high chrome bar would crack.
Melco casts manganese blow bars to ASTM A128 in Grades A, B-3, C and E-2. All castings are solution annealed and water quenched, the treatment that puts the carbides into solution and gives the steel its characteristic toughness.
These bars suit primary impact crushing, demolition waste, reinforced concrete and any feed where uncrushable material arrives without warning. In clean, highly abrasive rock they will wear faster than high chrome, so the choice is driven by impact rather than abrasion.
Applications
- Primary impact crushing of hard and mixed feed
- Recycled concrete and demolition waste with rebar
- Construction and demolition (C&D) recycling plants
- Feeds carrying tramp metal or uncrushable material
- Mobile crushing spreads working unscreened material
Features
What you get
Solution annealed and water quenched
The full ASTM A128 treatment, run in-house, so carbides are dissolved and the austenite is stable.
Handles tramp metal
Rebar and uncrushables deform the bar rather than fracturing it, protecting the rotor and reducing catastrophic failures.
Grade selected to section
Heavier sections move to Grade B-3 or the molybdenum-bearing E-2 so properties hold through the thickness.
Specifications
Manufacturing specification
Applies to manganese steel blow bars 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 |
|---|---|---|---|
| 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 |
| ASTM A128 Grade C | 1.05–1.35% C, 11.5–14.0% Mn, 1.5–2.5% Cr | 220–250 BHN as-cast | Where extra initial hardness is needed |
| ASTM A128 Grade E-2 | 0.7–1.3% C, 11.5–14.0% Mn, 1.8–2.1% Mo | 200–229 BHN as-cast | Heavy sections, faster work-hardening |
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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Mounting profile: the face that decides whether a bar seats square. -
Stedman-fit bars following heat treatment. -
Despatch yard: mobile impactor bars staged for export.
Questions
Manganese Steel Blow Bars: common questions
Why does a new manganese blow bar feel soft?
That is expected. ASTM A128 manganese steel is supplied at roughly 200–229 BHN and only develops its working hardness once it is being struck. Within the first hours of crushing the wear face work-hardens past 500 BHN while the core stays tough.
Will manganese steel blow bars work in limestone?
They will run, but in clean abrasive limestone a high chrome bar usually gives noticeably longer life. Manganese steel earns its keep where impact and tramp metal are the problem, not where pure abrasion is.
Do manganese blow bars need run-in before full production?
No special run-in is required, but the bars reach their best wear rate after the surface has hardened. Avoid grinding or machining the wear face, as that removes the hardened layer.
Are manganese steel castings magnetic?
Correctly heat-treated austenitic manganese steel is essentially non-magnetic. A strongly magnetic response often points to an incorrect heat treatment, which is one of the checks we run before dispatch.
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Enquiry
Enquire about manganese steel blow bars
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.