Precision Machined Components
Custom Bearing Inner Sleeves: Precision Machined to Your Print
In rotating equipment assemblies, the bearing inner sleeve is rarely a standard off-the-shelf component. When your design requires specific fits, unique material properties, or precise geometric control, SleeveMFG provides the manufacturing solution. We produce custom-machined inner sleeves, bearing spacers, and shaft adapters directly from your engineering drawings or 3D models.
We support projects ranging from single-unit MRO replacements to high-volume OEM production runs, ensuring every sleeve meets the dimensional and metallurgical requirements defined in your specification.
Machined from your files: PDF, STEP, DWG, or DXF drawings and 3D models accepted.
0.01 mm
Radial runout via OD/ID grinding
Ra 0.2 μm
Surface roughness, minimum
Ø3–500 mm
Outside diameter range
1500 mm
Maximum sleeve length
Engineering Focus
Precision Engineering for Bearing Fits
Bearing performance depends on the integrity of the interface between the shaft, the inner ring, and the sleeve. A poorly machined sleeve leads to vibration, premature bearing failure, and assembly misalignment. SleeveMFG focuses on the mechanical parameters critical to these assemblies.
≤ 0.01 mm
Concentricity & Runout
We utilize OD/ID grinding to achieve radial runout down to 0.01 mm, ensuring the sleeve maintains perfect alignment with the shaft axis.
H6 / h6
Dimensional Tolerances
We hold tight tolerances on both the bore and outside diameter — often H6/h6 or tighter — to ensure the correct interference or clearance fit required by your bearing manufacturer.
Ra 0.2 μm
Surface Finish
We achieve surface roughness down to Ra 0.2 μm, reducing friction and wear at the seal or bearing interface.
0.01 mm
Cylindricity
Essential for preventing uneven pressure distribution, our grinding processes ensure uniform contact across the entire sleeve length.
Capabilities
Manufacturing Capabilities
Our facility in Dongguan is equipped for the end-to-end production of precision sleeves, integrating multiple machining stages to deliver a finished component ready for your assembly line.
| Parameter | Capability |
|---|---|
| OD Range | Ø3 mm – Ø500 mm |
| ID Range | Ø1 mm – Ø450 mm |
| Max Length | 1500 mm |
| Grinding Tolerance | ±0.005 mm |
| CNC Turning Tolerance | ±0.01 mm |
| Surface Finish | Down to Ra 0.2 μm |
| Geometry | Concentricity, roundness, and cylindricity within 0.01 mm |
A Dual-Process Approach
We operate a mix of CNC turning centers for primary geometry and precision grinding machines for final sizing. This allows us to manage complex features while maintaining the dimensional accuracy required for bearing seats.
- Shoulders and flanges
- Internal keyways
- Snap-ring grooves
- Precision ground bearing seats
Materials
Material Selection for Bearing Assemblies
The operational environment of the bearing dictates the material specification. SleeveMFG machines a wide spectrum of industrial metals, ensuring the sleeve performs under the thermal and mechanical loads of your application.
Bearing Steels
52100 · GCr15
The standard for high-hardness, wear-resistant applications.
Stainless Steels
304 · 316 · 17-4PH · 420 · 440C
Essential for corrosive environments or food-grade machinery. 17-4PH is frequently used when high strength and corrosion resistance are both required.
Alloy Steels
4140 · 4340
Used for heavy-duty drive shafts and components requiring high tensile strength and toughness.
Bronze & Copper Alloys
Bushings · Sleeves
Often used for bushings and sleeves in high-speed or non-sparking environments.
Heat treatment coordination: If your prints require induction hardening, case hardening, or through-hardening, we coordinate these processes to ensure the finished sleeve meets your required HRC/HB hardness levels.
Finishing Services
Secondary Operations & Surface Treatments
Bearing inner sleeves often function as part of a larger sealing or protection system. Beyond machining, we provide the following finishing services to ensure the part is ready for installation.
01
Hardening
Quench and temper, nitriding, and induction hardening for wear-prone surfaces.
02
Plating & Coating
Hard chrome plating for wear resistance, electroless nickel for corrosion protection, or black oxide for environmental resistance.
03
Precision Finishing
Honing, lapping, and centerless grinding to meet specific friction coefficients.
One supplier, full control. By managing the entire supply chain — from raw material procurement to final coating — we reduce the logistics burden and quality risk associated with multi-vendor sourcing.
Who We Supply
Supporting OEM and MRO Requirements
We understand that the sourcing requirements for a maintenance repair shop differ significantly from those of an original equipment manufacturer.
Consistent, Repeatable Quality at Volume
Our quality management system tracks dimensions, material batches, and inspection reports, ensuring that the 1,000th sleeve is identical to the first.
- Tracked material batches and inspection reports
- Long-term supply agreements
- Scheduled releases for production planning
Fast-Turnaround Replacement Sleeves
When original parts are obsolete or lead times from the OEM are unacceptable, we manufacture replacements from samples or basic dimensions.
- Reverse-engineered from physical samples
- Manufactured from basic dimensions
- One-off and small-batch production with fast turnaround
Quality Assurance
Quality Inspection
We do not ship parts based on visual inspection alone. Every production batch is verified against the tolerances specified in your drawing. Our inspection lab utilizes:
CMM & Profile Projectors
Geometric verification
Bore Gauges & Micrometers
ID/OD sizing
Surface Roughness Testers
Finish quality confirmation
Hardness Testers
Heat treatment verification
Documentation with Every Shipment
All shipments include necessary documentation, including material test reports (MTRs) and inspection certificates upon request.
Start Your OrderGet Started
Request a Quote for Your Sleeve Project
To receive a formal quotation, please send your engineering files (PDF, STEP, DWG, or DXF) to info@sleevemfg.com. For the most accurate quote, please include:
-
1
Material Specification — e.g., 4140, 17-4PH.
-
2
Required Tolerances — for ID, OD, and length.
-
3
Surface Finish — required Ra value.
-
4
Quantity — for the initial order.
-
5
Heat Treatment or Coating — specifications.
Have a sample but no print? Contact us at info@sleevemfg.com to discuss how we can reverse-engineer the dimensions for your replacement sleeve.
Contact SleeveMFG
Send your drawings or sample details — our engineering team will respond with a formal quotation.
info@sleevemfg.com
Factory Address
Send Your Inquiry
Submit your project details below and receive a quotation for your custom bearing inner sleeves.