CNC Bearing Bushings are cylindrical metal sleeves precision-turned to establish accurate physical interfaces between shafts, housings, and rotating components. These components maintain tight radial and axial clearances, reduce friction, and preserve shaft alignment in continuous-duty machinery. Manufactured via multi-axis turning operations, each sleeve features controlled bore dimensions, uniform outer diameters, and consistent concentricity to support press-fit or slip-fit installation without secondary hand-fitting. Custom designs incorporate stepped profiles, oil retention grooves, locking shoulders, and lead-in chamfers based on supplied CAD models.
Technical Specifications
|
Parameter |
Capability Limit |
|
Bore Size Range |
3 mm to 150 mm |
|
Outer Diameter Range |
6 mm to 200 mm |
|
Dimensional Tolerance |
Down to ±0.005 mm |
|
Concentricity / Runout |
Within 0.01 mm |
|
Surface Roughness |
Ra 0.4 µm – Ra 1.6 µm |
|
Standard Chamfers |
0.5 x 45° lead-in edges |
Material Options
Stainless Steel (304, 316, 17-4 PH): Applied in corrosive environments, marine hardware, and high-temperature fluid systems where surface oxidation must be prevented.
Carbon Steel (1215, 1045, 4140): Standard selection for structural sleeves and high-load mechanical interfaces where high tensile strength and cost efficiency are prioritized.
Aluminum Alloys (6061-T6, 7075-T6): Lightweight solution offering low inertia, suitable for dynamic automation components and weight-sensitive assemblies.
Copper Alloys (Brass C36000, Bronze C93200): Selected for low coefficient of friction, inherent wear resistance, and self-lubricating characteristics in sleeve bearings.
Engineering Plastics (POM, PEEK, PTFE): Non-conductive, chemically inert options used in food processing, laboratory tools, and lightweight sliding assemblies.
Precision Turning Features
Controlled Internal Bores:
Internal diameters are bored or reamed to specific fit classes (such as H7 or H8) to match mating pin or shaft tolerances.
Concentric Turning Setups:
Outer diameters and inner bores are machined in the same clamping setup to eliminate eccentricity between internal and external surfaces.
Edge Deburring and Radii:
Machine-finished chamfers and polished internal edges prevent burr interference during automated press-fit assembly.
Functional Oil Grooves:
Single, double, or helical grooves can be cut into the inner wall to ensure continuous lubrication distribution across the sliding area.
Surface Finishing Treatments
Anodizing (Clear / Hardcoat):
Increases surface hardness and corrosion protection on aluminum alloys, preventing galling during movement.
01
Chemical Passivation:
Removes surface iron contaminants from stainless steel to form a continuous chromium oxide corrosion barrier.
02
Electroplating (Zinc, Nickel):
Provides sacrificial corrosion resistance and improves wear characteristics on carbon steel components.
03
Zinc-Nickel Plating:
Offers salt-spray corrosion protection for severe outdoor and automotive operational environments.
04
Black Oxide:
Creates a zero-buildup dark surface finish that maintains strict dimensional tolerances on steel parts.
05
Quality Control and Inspection
Material Certification: Spectrometric analysis verifies base metal composition against mill test reports prior to machining.
First Article Verification: Initial setup parts are measured with optical comparators and micrometer sets before production approval.
In-Process Bore Gauging: Three-point internal micrometers and plug gauges check bore tolerances throughout the production run.
Geometric Measurement: Coordinate measuring machines verify concentricity, perpendicularity, and roundness against drawing requirements.
Pre-Shipment Audit: Final sampling ensures surface finish standards, deburring, and dimensional limits match technical drawings.
Applications of CNC Bearing Bushings
Automotive Steering and Suspensions
Acts as pivot sleeves and alignment guides to maintain joint geometry and absorb multi-directional mechanical loads.
Industrial Automation Carriers
Provides low-friction guide interfaces for linear slides, pneumatic cylinders, and indexing machine tables.
Hydraulic Pump Bodies
Serves as shaft support sleeves, maintaining pressure tight seals and precise rotational alignment under high fluid pressure.
Medical Instrument Drives
Delivers smooth movement and precise positioning within small-scale electric actuators and diagnostic devices.
Conveyor System Rollers
Positions internal shaft bearings securely inside outer roller tubes to handle continuous material movement.
Selection and Ordering Considerations
Verify Mating Fits: Detail the exact shaft and housing tolerances to determine whether an interference, transition, or clearance fit is required.
Account for Coating Thickness: Factoring in plating or anodizing layers (typically 5 to 25 microns) ensures post-treatment dimensions stay within tolerance limits.
Evaluate Load and Speed: High rotational speeds require copper or lubricated plastic materials, whereas high static loads demand hardened steel options.
Packaging and Export Handling
Individual Part Protection:
Turned components are arranged in compartmentalized trays or wrapped in protective netting to prevent metal-to-metal impact.
Corrosion Inhibition:
Carbon steel and iron-based components are treated with volatile corrosion inhibitor paper or light rust-preventative oil prior to sealing.
Sealed Outer Crates:
Products are packed into reinforced cartons and palletized with stretch wrapping to protect against moisture during transit.
FAQ
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