Concave And Bowl Liners

A: Liner life depends on feed material hardness, abrasiveness, crusher setting, throughput rate, and operating practice. In aggregate quarrying of medium-hard limestone, a set of Mn18 liners in a mid-size cone crusher might last 800–1,200 operating hours. In primary hard rock mining with highly abrasive ore, the same liners may need replacing in 300–500 hours. Duma's modified alloy grades are engineered to extend service life compared to standard unmodified manganese steel, and our technical team can advise on grade selection based on your specific conditions.

A: The concave is the fixed outer liner secured to the main crusher frame. The bowl liner is the moving inner liner mounted on the crushing head. In some terminology, "mantle" refers specifically to the inner moving liner (what Duma classifies as the bowl liner), while "concave" always refers to the fixed outer liner. The terms vary by brand and region, so when ordering, it helps to specify fixed outer liner (concave) or moving inner liner (bowl liner/mantle) to avoid confusion.

A: Yes. Duma's 4,000+ pattern library covers most production crusher models from major brands. For older or less common models not in the library, our engineering team can reverse-engineer the part from a worn sample or from customer-supplied drawings. Contact our technical team with the crusher brand, model number, and serial number and we will confirm availability and lead time.

A: Uneven or one-sided wear almost always results from uneven feed distribution into the crushing chamber. This can be caused by a conveyor discharging off-center, a feed chute directing material to one side, or a poorly positioned scalping screen. Correct feed distribution so the chamber fills symmetrically. Running choke-fed (full chamber at all times) is the most effective way to promote even liner wear and protect the crusher.

A: Ensure the seating surfaces of the frame and head are clean, free of old backing compound residue, and undamaged. Apply fresh backing compound mixed to the manufacturer's specified ratio and pour to fully fill the cavity behind the liner — voids in the backing create unsupported liner areas that crack under load. Install and torque the locking hardware to specification. After the first 8–12 hours of operation, check and re-torque the fasteners, as some liner settling is normal. Inspect again at 48 hours.

A: Standard replacement profiles for common models held in stock ship within 7–10 days of order confirmation. Custom profiles, non-standard models, or large volume orders requiring fresh production have a typical lead time of 35–45 days. Contact our sales team for a specific confirmation based on your model and quantity.

A: Yes. Duma accepts small trial orders specifically to allow customers to verify liner quality, fit, and wear performance before committing to larger volumes. There is no fixed minimum order quantity — contact us with your requirements.

A: A choke-fed cone crusher processes material through particle-on-particle compression, where rock breaks against other rock rather than directly against the steel liner surface. This is more energy-efficient, produces a more cubical product shape, and significantly reduces the direct metal-on-rock abrasion that removes liner mass. Operating below choke feed forces rock directly against the liner faces, accelerating wear and increasing the risk of fatigue cracking.

A: Backing compound (crusher backing) is a two-component epoxy resin poured between the liner and the frame or head. Its function is to create a perfectly continuous, fully supported contact surface behind the liner. Without proper backing, the liner is supported only at its high points, causing stress concentrations that lead to cracking. Even small voids left by improper mixing or insufficient pour volume can cause premature liner failure. Always use a purpose-formulated crusher backing product and follow the mix ratio exactly.

A: Yes. Duma replacement liners are produced from patterns developed to OEM dimensional specifications and are manufactured to the same tolerances. They are designed to be direct drop-in replacements for the corresponding OEM parts without field modification. If any fit issue arises after installation, contact our technical team immediately — this is extremely rare and we will resolve it promptly.

A: For high-impact primary and coarse secondary crushing of hard, abrasive ores such as gold or copper ore, Mn22 (approximately equivalent to ASTM A128 Grade E-2) is generally the first recommendation. If the ore is highly abrasive but impact levels are moderate (tertiary stage), Mn18Cr2 or a TIC insert liner may offer better performance. Duma's technical team will recommend a grade based on your ore's Bond Work Index and silica content if you can provide that data.

A: Duma regularly produces and supplies Mn22 (22% manganese content, ASTM A128 Grade E-2) for extreme high-impact applications. For applications where even Mn22 wears too quickly due to high abrasion rather than impact, TIC-insert liners are available as the next step up.

A: Duma uses computer-controlled automated heat treatment furnaces programmed for stepped temperature ramp profiles. The core process is solid solution treatment followed by water toughening (forced water quenching using high-power circulation pumps) to lock in a stable, fully austenitic microstructure. Heat treatment curves are recorded for every batch and retained as part of the production traceability file. Post-treatment metallographic inspection confirms the microstructure before parts proceed to machining.

A: Each shipment is accompanied by a material certificate, heat treatment curve records, hardness test report, and dimensional inspection report. For customers requiring third-party inspection or additional certifications, this can be arranged on a project basis. All documents are batch-traceable to the specific production run.

A: Send CAD files (DXF, DWG, STEP, or PDF drawing) to our sales team by email. If you have a worn sample but no drawing, ship it to our facility and our engineering team will measure and reconstruct the original geometry for your review before production begins. For crusher model-based replacements, provide the brand, model number, and cavity configuration (coarse/medium/fine) and we will confirm the matching pattern from our library.