Industrial Bronze Sleeve Bearings and Friction Components Bunting Bearings

Technical evaluation and supply of Bunting Bearings bronze journal bushings, continuous-formed alloy stock, and self-lubricating porous components.

Formed Bronze Sleeve Bearings C93200

Bunting formed bronze sleeve bearings and flanged bushings are produced from high-grade C93200 leaded bronze meeting SAE 660 requirements. The alloy provides high anti-friction qualities, resilience under radial shock loads, and long service life in industrial gearboxes, presses, and pumps.

Metric and inch cylindrical sleeve bushings engineered for heavy machinery journal assemblies
High-leaded bronze alloy C93200 offering dependable embeddability and anti-galling performance
Precision machined oil grooves including straight, figure-eight, and circular distribution paths
Strict dimensional tolerances on outside and inside diameters for interference housing fits

Continuous-Formed Bronze Bars and Wear Plates

Bunting supplies solid rounds, hollow cored tubes, and heavy-duty flat wear plates manufactured through continuous and centrifugal forming processes. The fine-grained metal structure prevents internal voids and porosities during precision turning of high-load friction components.

Solid rounds and thick-wall hollow tubes formed from C93200, C89835, and C95400 bronze alloys
Flat wear plates and slideway guide strips intended for mechanical stamping press assemblies
Dense metal grain structure free of inclusions allowing rapid precision turning and milling
Extensive dimensional selection of cut-to-length stock for plant maintenance and machining shops

Powdered Metal Porous Bushings SAE 841

Bunting porous sintered metal bushings are fabricated by compacting bronze powder and impregnating the porous structure with lubricating oil up to 20 percent by volume. During rotation, hydrodynamic capillary action draws oil to the mating journal, minimizing routine maintenance requirements.

Oil-impregnated bushings in SAE 841 Bronze, lead-free ECO, and BB-16 for electric motor shafts
High-strength sintered iron-copper alloy SAE 863 thrust washers for elevated mechanical loads
Self-contained hydrodynamic oil replenishment active during rotation and reabsorbed upon rest
Precision tooling dimensions across cylindrical and flanged configurations for blower drives

Engineered Polymer and Composite Bushings

For friction assemblies exposed to corrosive chemicals, high thermal environments, or dry-running conditions, Bunting supplies high-performance polymer bushings. Fabricated from PTFE compounds, Nylon 101, and DuPont Vespel, these parts retain dimensional stability under mechanical stress.

Dry-running metal-polymer composite bushings series BU incorporating a slippery PTFE lining
Chemically resistant cylindrical components manufactured from Nylon 101 and JLON fluoropolymers
Precision machined high-temperature DuPont Vespel bearings for vacuum and aerospace equipment
Low kinetic friction coefficient eliminating liquid grease contamination in processing machinery

Lube-Align Self-Aligning Mounted Units

Bunting Lube-Align mounted bearing units integrate an oil-embedded bronze sleeve inside a spherical housing that accommodates shaft angular misalignments. The design prevents binding and excessive journal wear caused by frame flexing or shaft deflection along industrial belt conveyors.

Versatile Lube-Align Standard and Platinum series housed in rugged formed mounting brackets
Rigid mounting options including standard base pads, two-bolt flanges, and three-bolt flanges
Spherical cartridge seating providing smooth angular alignment correction for rotating shafts
Integral porous bronze insert ensuring steady hydrodynamic lubrication during continuous duty

Tailored Bearings and Print-to-Part Components

Bunting manufacturing shops operate precision CNC turning and milling centers to produce tailor-made bushings, wear rings, and split sleeves strictly to customer drawings. The plant handles precision finishing of cylindrical components from 1/4 inch through 20 inches in diameter.

CNC turning and multi-axis milling handling diameters from 6 mm up to 500 mm with fine tolerance
Fabrication of split journal half-bushings, thrust washers, and customized locating pins
Complex lubrication profiles including helical channels, cross-drilled feed ports, and pockets
Rigid geometric inspection verifying journal runout, concentricity, and target surface finish

Selecting Sleeve Bushings by Running Fits and Housing Tolerances

When specifying Bunting sleeve bushings, proper matching of the nominal inner bore, outside diameter, and length is essential for reliable operation.

For standard cylindrical journal bushings, press-fitting into the rigid frame requires a calculated interference fit to prevent rotational slipping under dynamic torsional loads.

The inner diameter shrinks slightly after press insertion, so initial bore dimensions must account for wall contraction to preserve the required hydrodynamic running clearance.

Recommended mating shaft tolerances follow standard ISO f7 or h6 ground limits with surface hardness above 50 HRC to prevent galling during boundary startup conditions.

Pressure-Velocity PV Calculations for Journal Bearing Assemblies

The operational longevity of Bunting journal bearings depends directly on the calculated product of bearing pressure P and rubbing velocity V.

For formed bronze bushings in C93200 alloy with continuous oil replenishment, allowable continuous PV ratings reach up to 75000 psi-fpm, with maximum static bearing loads reaching 4000 psi.

Operating beyond recommended PV thresholds causes rapid thermal buildup, thinning the hydrodynamic lubricant film and shifting the friction regime into severe boundary contact.

Engineering the bushing contact area ensures balanced load distribution, low friction, and long endurance in high-load industrial machinery.

Material Characteristics of C93200 Leaded Tin Bronze Alloy

Alloy C93200 conforming to SAE 660 is a widely recognized industrial standard for general-purpose sleeve bushings and thrust bearings. The high lead content distributed evenly throughout the copper-tin matrix acts as a solid lubricant during brief startup intervals before full oil film development.

In addition, C93200 bronze offers excellent foreign particle embeddability, safely absorbing microscopic abrasive debris into the soft metallic matrix and protecting hardened steel journals from scratching.

The alloy demonstrates smooth machinability, high resistance to pounding shock loads, and long-term chemical resilience when exposed to industrial lubricants.

Sintered Porous Bronze Bushings SAE 841 and Operational Care

Bunting SAE 841 Bronze powdered metal parts are produced by pressing pure copper and tin powders into precision tooling and sintering them in a protective atmosphere.

The resulting porous bronze structure is vacuum-impregnated with refined petroleum oil, filling 18 to 20 percent of the component volume with lubricating fluid. When the journal rotates, capillary action and frictional heat draw oil to the rubbing surface to form a supporting hydrodynamic film.

When rotation ceases, capillary forces draw the oil back into the internal porous network, preventing external oil leakage and keeping electric motor shafts clean.

Heavy-Duty Friction Protection and Internal Lubrication Grooves

For demanding industrial machinery involving low rubbing speeds and heavy shock loads, Bunting machines specialized distribution grooves into the bushing inner bore.

Depending on the external lubrication supply system, groove geometries include circular annular rings, single or double helical spirals, and closed figure-eight channels. Grooves are engineered with closed ends to prevent oil from escaping freely past the bushing edges.

In high-temperature or heavily contaminated environments, the internal grooves can be filled with solid graphite plugs, providing a permanent dry lubricant film that resists journal seizure.

Press-Fitting Installation and Post-Assembly Sizing Guidelines

Installing bronze sleeve bushings into machine frames requires controlled axial force and properly stepped pilot mandrels to prevent cocking during insertion. The insertion arbor must feature a shoulder square to the bore axis, distributing uniform pressing force over the entire bushing end face.

Hammering directly against the bronze surface is prohibited, as impact shocks distort roundness and crack flanges. For heavy interference fits, sub-zero cooling of the bushing or moderate warming of the housing bracket facilitates smooth insertion.

After installation, the internal journal bore can be finished with a sizing reamer.

Bunting Bearings and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of Bunting Bearings and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.