Custom Precision Bearing Spacers Machined to Your Drawings
SpacerMFG manufactures custom precision bearing spacers, spacer sleeves, and shaft bushings engineered strictly to customer drawings.
Based in Shenzhen, our precision machining facility produces turned and ground metal components with controlled parallelism, face runout, and micro-inch surface finishes for critical bearing preload and shaft alignment.
±0.002 mm
Thickness capability
Ra 0.2 µm
Ground or lapped finish
24 hours
Typical RFQ response
Built for critical assemblies
Prototype runs, short-run production, and high-volume OEM contracts for automation, robotics, automotive, and heavy machinery.
At-a-glance capability
Quick Manufacturing Specs
Select turned, ground, or lapped processes according to the dimensional stability and surface contact requirements of your bearing assembly.
| Parameter | Standard Capability | High-Precision Capability |
|---|---|---|
| Outer Diameter (OD) | 3.0 mm to 350.0 mm | Customized to drawing |
| Inner Diameter (ID) | 1.5 mm to 320.0 mm | Bore tolerances down to ±0.005 mm |
| Length / Thickness | 1.0 mm to 400.0 mm | Thickness tolerances down to ±0.002 mm |
| Parallelism & Flatness | 0.01 mm | Up to 0.002 mm via surface grinding |
| Surface Finish (Ra) | Ra 0.8 µm turned | Ra 0.2 µm–Ra 0.4 µm ground/lapped |
| Primary Materials | Aluminum, stainless steel, carbon steel, alloy steel, brass, and bronze | |
| Secondary Operations | Heat treatment, surface grinding, anodizing, plating, passivation, and laser marking | |
Engineering function
Control bearing preload, alignment, and assembly life
Bearing spacers, distance rings, and precision spacer sleeves set the axial distance between two bearing rings mounted on a common shaft or housing bore. They eliminate manual shimming and stabilize internal clearances under dynamic axial and radial loads.
Why micron-level control matters
- Spacer length variance changes preload. Excessive preload can create thermal buildup and early fatigue failure.
- Excessive clearance can cause shaft play, chatter, and reduced system stiffness.
- Matched-length spacer sets allow specified shaft-nut torque without trial-and-error shimming.
Bearing spacer arrangement
[ Shaft / Axis Centerline ] ================================================= [ Bearing A ] <--- Spacer ---> [ Bearing B ] +-----------+ +--------------+ +-----------+ | Outer Ring| | Outer Spacer | | Outer Ring| +-----------+ +--------------+ +-----------+ | Ball/Roll | | Ball/Roll | +-----------+ +--------------+ +-----------+ | Inner Ring| | Inner Spacer | | Inner Ring| +-----------+ +--------------+ +-----------+ =================================================
Non-parallel faces
Can cock bearing rings, unevenly distribute ball loads, and increase operating noise.
Bore eccentricity
Shifts ID-to-OD wall thickness and can affect rotation balance at higher speeds.
Burrs and flash
Prevent flush seating against shoulders and may cause preload loss over operating cycles.
Manufacturing workflow
From CNC turning to verified final dimensions
SpacerMFG runs specialized CNC turning and precision grinding cells configured for thin-walled rings, stepped sleeves, and high-aspect-ratio spacers.
CNC Lathe Turning
Rough and finish OD/ID machining, chamfers, grooves, and single-setup concentricity control.
Face Grinding & Lapping
Double-disc grinding controls parallelism to 0.002 mm; lapping produces seating surfaces down to Ra 0.2 µm.
Deburring & Washing
Vibratory deburring, edge conditioning, ultrasonic cleaning, and optional drilling, tapping, or oil channels.
Quality Inspection
CMM and optical checks, material certificates, and dimensional verification against the approved drawing.
Machining details for demanding geometries
- Thin-wall machining: Optimized chucking pressure and custom soft jaws help prevent distortion in spacer sleeves.
- Internal features: Snap-ring grooves, lubrication holes, oil-retention channels, and internal threads can be added for retention.
- Secondary operations: Cross-drilled oil ports, set-screw holes, weight-reduction pockets, and burr-free edge conditioning are available.
Choose the right process
Turned spacers suit general machinery, low-speed shafts, conveyor rollers, and static assemblies. Turned-plus-ground spacers are recommended for machine-tool spindles, servo gearboxes, high-RPM hubs, robotic reducers, and aerospace actuators.
CNC turned
±0.02–±0.05 mm; Ra 0.8–1.6 µm
Surface ground
Down to ±0.002 mm; Ra 0.2–0.4 µm
Materials & protection
Match the spacer to its load, environment, and service life
Material and surface treatment selection helps prevent galling, fretting corrosion, and mechanical deflection under load.
Aluminum
6061-T6 and 7075-T6 for lightweight, non-magnetic assemblies, robotics, aerospace, and drone motors.
Stainless steel
304, 316, and hardened 440C for corrosion resistance and high compressive loads.
Carbon & alloy steel
1045, 4140, and 52100 for high strength and thermal expansion compatibility with bearings.
Brass & bronze
C36000 brass and SAE 660 bronze offer machinability, anti-galling, and self-lubricating properties.
Available finishing and treatment options
Anodizing
Type II or Type III hardcoat for aluminum wear and corrosion protection.
Electroless nickel
Uniform bore and thread coverage with strong corrosion resistance.
Black oxide
Low-cost rust-inhibitive layer for steel without changing critical dimensions.
Passivation
Removes free iron from stainless surfaces for medical and food machinery.
Heat treatment
Case hardening or vacuum treatment for impact and friction conditions.
Quality assurance
Every batch verified against your print
Inline and final dimensional inspections confirm that every batch meets drawing specifications before shipment. Material Test Reports and dimensional inspection reports are available upon request.
Inspection protocol
- 1.Raw material spectrometer test
- 2.First-Article Inspection (FAI)
- 3.In-process bore and OD micrometer checks
- 4.CMM parallelism and flatness check
- 5.Surface roughness tester verification
Parallelism & flatness
Checked using dial indicators on surface plates or coordinate measuring machines.
Length matching
Inner and outer spacer sets are measured under controlled temperature for exact height matching.
Concentricity
Precision mandrels confirm bore-to-OD alignment and help prevent radial imbalance at high RPM.
Burr-free verification
100% visual and optical magnification checks confirm clean chamfered edges and flush seating.
Application coverage
Designed for demanding OEM assemblies
Automation
Linear guide blocks, servo motor shafts, and pneumatic actuators.
Robotics
Aluminum and steel spacers for strain wave gearing and planetary gearboxes.
Machinery OEMs
Hardened sleeves, shim rings, and bearing housings for industrial machines.
Automotive
Wheel bearing spacers, suspension pivot bushings, and drive-shaft distance tubes.
Medical
Passivated 316L components for rotary tables, centrifuges, and diagnostic devices.
Request a quote
Send your bearing spacer drawings for technical review
SpacerMFG manufactures custom bearing spacers directly from your engineering files. Our team will review geometry, tolerances, material, and finishing requirements to provide a fast-turnaround quotation.
Typical RFQ response
Within 24 hours
Production lead time
7–10 days prototypes; 2–3 weeks production
Factory Address:
Engineering Email: info@spacermfg.com
What to include in your RFQ
- 1Part drawing in PDF, STEP, IGES, or DWG format.
- 2Material grade and heat treatment requirements.
- 3Prototype quantity and expected annual volume.
- 4Critical bore, OD, length, thickness, and parallelism tolerances.
- 5Surface finish, coating, plating, passivation, or oxide specifications.
Ready to quote your bearing spacer project? Submit your technical requirements through our inquiry channel.