C93200 and C93700 Bronze Eccentric Bushings and Socket Liners for Cone Crushers
For cone-crusher eccentric bushings and socket liners, retain the machine maker’s approved material, geometry and lubrication requirements. C93200 and C93700 are different leaded tin bronzes; neither is a universal crusher replacement grade. Confirm the exact bearing position before quoting, because a cylindrical eccentric bushing and a spherical socket liner require different drawings and inspection.
This guide helps industrial buyers prepare a replacement enquiry. It does not identify an OEM’s undisclosed alloy or claim that BONIU stocks an approved part for a specific crusher model.
Eccentric bushing, socket liner or bowl liner?
| Component | Function and geometry to verify | Common purchasing error |
|---|---|---|
| Eccentric bushing | A journal-bearing sleeve within the eccentric arrangement; identify the inner and outer mating parts and any eccentricity defined by the drawing. | Ordering only ID × OD × length without the oil passages, retention features or datum relationship. |
| Bronze socket liner / spherical support liner | Supports the head-ball interface in designs using this arrangement. The spherical surface and oil distribution are critical. | Treating a spherical liner as a straight sleeve or defining its shape from a worn central thickness. |
| Bowl liner / concave crushing liner | A crushing-chamber wear component. It is a different part from the bronze socket-support liner. | Using “bowl liner” as the only description when the intended enquiry is for the bronze spherical support. |
Metso’s MP Series brochure distinguishes bronze journal bushings from the bronze socket liner, and describes full-film journal lubrication and oil grooves at the spherical support.[1] These observations identify one documented crusher architecture; they do not establish the construction of every cone crusher.
C93200 and C93700: compare chemistry, then the specification
The CDA composition reference separates these high-leaded tin bronzes. The selected values below are weight percent and omit other limits and footnotes.[2]
| Grade | Tin | Lead | Zinc | Procurement implication |
|---|---|---|---|---|
| C93200 | 6.3–7.5% | 6.0–8.0% | 1.0–4.0% | Do not describe it as the same material as nominal 80-10-10 bronze. |
| C93700 | 9.0–11.0% | 8.0–11.0% | ≤0.8% | A separate alloy; approval requires the full ordered material and casting requirements. |
The producer literature discusses the lubricity and ability of high-leaded tin bronzes to accommodate some foreign matter.[3] That material characteristic is not permission to operate a crusher with dirty oil or a failed supply. It also does not establish a higher allowable load for a replacement part.
Keep the OEM grade visible. If a drawing calls for a different alloy, a quotation labelled “C93200/C93700 or equivalent” leaves the material unresolved. Ask the supplier to name one proposed grade and standard and identify deviations for the equipment owner’s approval.
Do not add C86300 to an acceptable-material list merely because it is a high-strength copper alloy. A material change also changes the tribological pairing and acceptance basis. The BONIU material-composition reference helps compare grade systems, but does not approve an OEM replacement
A burnt bushing is a system investigation
Metso’s HP maintenance guidance identifies oil overheating, lockup and bronze debris as possible burnout indicators. It lists lubrication faults and operating causes such as off-centre feed, an excessively small closed-side setting and incorrect rotation.[4] The practical inference is that ordering a harder bronze may leave the initiating cause unresolved.
| Observation | Evidence to preserve | Question for the maintenance team |
|---|---|---|
| Scoring or bronze debris | Photographs, debris location, oil-sample results and the removal report. | Was contamination introduced, generated by rubbing or left from an earlier failure? |
| Heat discolouration or smearing | Lubricant identity, supply/return temperature trends and alarm history. | Was oil delivery adequate under the actual load and start-up conditions? |
| Uneven or localised wear | Measurements by axial plane and angular direction; mating-part condition. | Is the seat tapered, out of round or misaligned? |
| Repeat failure after replacement | Feed conditions, setting changes, load trends and previous inspection records. | Has the original system or operating cause actually been corrected? |
This evidence matrix is engineering analysis for enquiry preparation, not a remote diagnosis. Follow the machine’s shutdown and maintenance procedure and have the responsible service engineer determine repair acceptance and return to service.
Measure the mating parts, not only the damaged bronze
For the eccentric journal position
Map shaft and housing measurements to drawing datums. Record axial position and measuring direction so the inspector can distinguish taper, ovality and local damage. Do not turn a worn average diameter into a new nominal size without an approved repair scheme.
As a model-specific example, Metso’s HP guidance calls for measurements at at least four heights and two positions 90 degrees apart, followed by tolerance review with technical assistance.[4] Use the measurement plan required for the actual machine; this article does not transfer HP tolerances to other models.
For the socket-support liner
Identify the spherical radius, datum relationship, seating geometry, locating features, oil grooves and corresponding head-ball condition. Agree how the specified profile and contact requirements will be inspected. A correct alloy and outer diameter cannot compensate for an incorrect spherical surface.
For both parts, distinguish the retention fit from the lubricated running interface. State whether drawing limits apply before fitting or in the installed condition. Resolve any approved machining after fitting and protect oil passages from burrs and debris.
Preserve the designed oil film and oil route
Metso’s lubrication guidance explains that contaminated oil can abrade bearing surfaces and increase clearances. It highlights temperature and pressure trends, return-screen inspection, oil analysis and clean breathers.[5] Its machine-specific intervals and temperatures are not universal acceptance limits; use the current manual for the installed crusher.
The drawing review should locate the oil inlets, drilled passages, grooves, outlet paths and sealing features. Keep their orientation tied to the assembly datums. A familiar groove pattern from a general-purpose sleeve may interrupt the intended bearing surface or change the flow path.
- Oil specification: provide the machine-approved lubricant and the relevant start-up and operating conditions.
- Passage alignment: verify that the installed part connects to the intended feed and does not obstruct drainage.
- Cleanliness: agree the cleaning and inspection procedure after a failure, including affected galleries and mating parts.
- Commissioning: follow the correct machine manual’s pre-lubrication, checks and run-in procedure; do not copy another model’s sequence.
Adding graphite plugs does not turn an oil-lubricated crusher journal or spherical support into an approved dry-running bearing. It changes the bearing construction and requires a separate design review.
Use a release checklist for the replacement order
- Identify: crusher maker, model, serial applicability, part number, bearing position and drawing revision.
- Specify: exact alloy, casting/product standard, material condition and permitted deviations.
- Define: critical bore or spherical profile, fits, datum scheme, oil features, finish and installed acceptance requirements.
- Document: measured mating-part condition, required chemistry and dimensional records, traceability and first-article review.
- Release: obtain the equipment owner’s approval of any material or geometry change before manufacturing the replacement batch.
A sample is useful for identifying features, but it may be distorted, worn or previously repaired. Ask which dimensions come from the approved design and which were measured from the failed part. Keep those two information sources separate in the inspection plan.
Frequently asked questions
Is C93700 always better than C93200 for a crusher?
No universal ranking is established. Different chemistry does not prove suitability for an unidentified bearing position. Retain the approved grade or have a proposed alternative assessed against the complete design and duty.
Is a bronze socket liner the same as a bowl liner?
No. In the architecture discussed here, the bronze socket liner supports the head-ball interface; the bowl liner belongs to the crushing chamber. Send the assembly position and part number to avoid an ambiguous enquiry.
Can graphite plugs solve an oil-starvation failure?
They are not a substitute for restoring the designed oil system. Any change to the bearing construction requires engineering approval, including review of remaining load-bearing metal and lubrication.
Can a supplier copy a damaged bushing?
A sample can support a drawing review. Recover and approve original dimensions, material requirements and oil features before accepting a production drawing, particularly when mating components are also worn.
Request a crusher-bushing drawing review
Send the approved drawing, part number and bearing position, required alloy and standard, shaft/housing or head-ball measurements, lubrication details, failure photographs, quantity and inspection requirements.
Send drawings for review or email sales@boniubushing.com. Manufacturing feasibility, material availability and quotation scope are confirmed for the specific enquiry. A quotation does not establish OEM affiliation or machine approval.
Technical references
- Metso: MP Series cone-crusher brochure. Journal-bushing and bronze socket-support descriptions in the rotating-assemblies section.
- Copper Development Association: cast-bronze UNS composition reference. Separate C93200 and C93700 chemistry entries; consult complete limits and footnotes.
- Wieland Concast: C93700. High-leaded tin-bronze material characteristics; not a crusher-specific approval.
- Metso: avoiding HP eccentric-bushing burnout. Failure indicators, possible causes and mating-part measurement example.
- Metso: five steps for a crusher lubrication system. Contamination, oil monitoring, screens, analysis and breathers.
The OEM sources describe their named machines, not BONIU performance. The enquiry checklist, evidence matrix and drawing-review analysis are original engineering guidance. They do not assign a grade to an undisclosed OEM component, set operating limits or replace the applicable machine manual.