Crusher Hammers for Hammer Mills and Impact Crushers
Crusher hammers—also called blow bars or hammer heads depending on the equipment type—are the primary working element in impact crushers, hammer mills, and ring granulators. Operating at high rotational speed under continuous impact loading, they must sustain both surface abrasion and body impact without premature fracture. Mine Components manufactures crusher hammers in manganese steel, chrome-molybdenum alloy steel, and high-chromium iron, with material selection matched to the specific equipment and feed material.
We supply hammers as direct replacements for OEM parts and as custom designs produced to client drawings, covering a weight range from under 5 kg per piece to over 300 kg for large primary hammer mills.
Applications
Our crusher hammers are used in the following equipment types and industries:
Hammer mills — coal processing, cement raw material preparation, mineral grinding, industrial waste processing. Hammers operate at high tip speeds (typically 25–45 m/s) and must maintain dimensional stability under cyclic fatigue loading while resisting abrasive wear from the processed material.
Impact crushers (horizontal shaft) — aggregate production, limestone and basalt crushing, recycling. Blow bars installed on the rotor receive direct primary impact from feed material and require a material that balances initial hardness with sufficient toughness to resist fracture from tramp material events.
Ring granulators and coal crushers — coal handling terminals and power plant coal preparation. These applications involve relatively low abrasivity but continuous high-frequency impact, with a preference for toughness over hardness in the material selection.
Cement and building materials crushers — limestone, clinker, and gypsum processing. High-abrasivity feed combined with moderate impact energy favors chrome-alloy or high-chromium materials in many cement applications.
Material Grades and Selection
The material selection for crusher hammers is more complex than for jaw plates because the loading mechanism—high-velocity impact rather than sustained compression—changes the performance requirements significantly. Three principal material families are available:
Manganese Steel (Mn13, Mn14)
Appropriate for applications where impact dwell time is sufficient to generate progressive work hardening—typically harder rock and mineral applications with tip speeds above 30 m/s. Manganese hammers provide excellent toughness and resistance to fracture from oversize feed or tramp metal, making them the safer choice in applications where feed control is imperfect. In soft-material or coal applications, manganese may not harden sufficiently and will wear faster than harder alternatives.
Chrome-Molybdenum Alloy Steel
Heat-treated alloy steel (typically 3–5% Cr, 0.5–1.5% Mo) offers higher initial hardness (300–400 HB) combined with the toughness to resist fracture in moderate-impact environments. This material is widely used in aggregate hammer mills and impact crusher blow bars where the feed is pre-sorted and tramp metal risk is managed. Chrome-moly hammers outperform manganese in applications where the impact energy is insufficient to fully work-harden the manganese surface.
High-Chromium Iron (GX260Cr27 and similar)
High-chromium white iron achieves initial hardness of 58–65 HRC through carbide precipitation, providing superior abrasion resistance in applications where hardness, not toughness, is the limiting factor. Appropriate for fine-grinding applications and cement hammer mills processing hard limestone with high silica content. High-Cr iron hammers are brittle relative to steel alternatives and are not recommended where tramp metal risk exists or where shock loading is unpredictable. Typically used in sealed applications with reliable pre-screening.
Hammer Types and Geometry
Crusher hammers vary significantly in geometry depending on the equipment design. We produce the following types:
Solid forged or cast hammers — single-piece construction, most common in heavy-duty primary hammer mills. Pin hole or eye geometry is machined to tolerance to ensure secure mounting on the rotor shaft or hammer pin.
Composite hammers (hammer head + hammer arm) — two-component designs in which the hammer head is the consumable wear element and the hammer arm provides the structural connection to the rotor. The head is replaced independently when worn, reducing total replacement cost per cycle. See our Hammer Arms and Hammer Heads page for further detail on this system.
Blow bars for horizontal shaft impact (HSI) crushers — rectangular cross-section inserts retained in rotor pockets by mechanical wedging. Available in manganese steel, chrome-moly, and high-Cr iron depending on application. Full-width bars spanning the rotor length are standard; segmented bars are available for rotors where rotor pocket geometry makes single-piece removal impractical.
Customization Capability
We support the following custom modifications: hammer body weight adjustment (by modifying cross-section or length to match rotor balance requirements), pin or shaft hole diameter and tolerance, surface profile on the impact face (flat, stepped, or profiled for specific size reduction objectives), material grade substitution for performance improvement, and modified geometry where OEM design is available but a geometry change is required to address a recurring failure mode.
For crusher models where the OEM no longer supplies replacement hammers, we can manufacture to worn originals or to reverse-engineered drawings subject to dimensional condition of the reference part. All client drawings and part geometry are handled under NDA.
Rotor Balance Considerations
Crusher hammer rotors are dynamically balanced systems. Replacing hammers without attention to rotor balance can introduce vibration that accelerates bearing wear and shortens rotor service life. For high-speed rotors operating above 700 rpm, we recommend ordering replacement hammers in matched sets with individual weights held to within ±50 g of each other across the set. We can weigh and group hammers to a specified weight tolerance as part of the supply, at no additional cost when specified at the order stage.
Manufacturing Process and Quality Assurance
Crusher hammers are manufactured by casting (for manganese and high-Cr iron grades) or by casting and machining (for alloy steel grades). Heat treatment is performed to specifications appropriate to the alloy: manganese steel hammers undergo solution annealing and water quenching; alloy steel hammers undergo austenitizing, quenching, and tempering to achieve the target hardness range; high-chromium iron hammers are destabilization heat treated and air-quenched to convert retained austenite and maximize carbide hardness.
Each production batch is documented with: chemical composition report per melt, hardness test results across the hammer body, dimensional inspection records against the drawing, heat treatment curves, and where specified, magnetic particle or penetrant inspection results. Full documentation is supplied with each delivery.
Ordering and Lead Times
Standard crusher hammers in common materials and geometries are available with lead times of 3–5 weeks from drawing confirmation. High-Cr iron hammers involving complex heat treatment schedules may require 5–7 weeks. Composite hammer head sets for large mills may require 6–8 weeks if pattern tooling needs to be produced for a non-standard geometry.
To request a quotation, provide the crusher or mill model, hammer drawing or OEM part number, material grade if known, and required quantity. We will confirm compatibility and provide a detailed offer within 1–2 working days.
Request a Quote for Crusher Hammers →
Related Products
Clients sourcing crusher hammers typically also require Impact Plates and Jaw Plates. Complete wear part sets for a crushing circuit can be supplied from Mine Components, simplifying procurement and ensuring documentation consistency across all components.