Precision CNC Machined Bushings & Spacers

We routinely achieve H7 bore tolerances (±0.005-0.010mm depending on diameter) through precision reaming. For applications requiring tighter tolerances, we can provide H6 bores (±0.002-0.005mm) through grinding. The specific tolerance capability depends on bushing diameter, length, and material. Bronze bushings can be held tighter than steel due to better machinability.

Plain bushings are simple cylindrical sleeves that provide radial support only. Flanged bushings have an integral flange (head) on one or both ends that provides axial positioning and can support thrust loads. Flanged bushings are easier to install and prevent axial movement, while plain bushings are more compact and lighter. The choice depends on your application's load direction and mounting requirements.

Yes, we can machine various lubrication groove patterns including straight axial grooves, spiral grooves (30-45° helix angle), circumferential grooves, and herringbone patterns. We can also add oil holes connecting the OD to ID, and oil pockets for grease retention. The groove pattern is selected based on shaft rotation direction, speed, and lubrication method. Grooves should be positioned away from the load zone for optimal performance.

For self-lubricating applications, we recommend oil-impregnated sintered bronze (Oilite), PTFE-lined composite bushings, or solid PTFE composites. Bronze Oilite bushings work well for moderate loads and speeds with minimal maintenance. PTFE composites offer the lowest friction and work in dry or wet conditions but have lower load capacity. Graphite-bronze combinations provide good performance at higher temperatures. Material selection depends on your PV (pressure-velocity) limits, temperature, and environment.

Press-fit interference depends on bushing material, housing material, diameter, and wall thickness. For bronze bushings in steel housings, typical interference is 0.005-0.015mm per 25mm of diameter. Steel bushings in steel require tighter interference (0.015-0.025mm per 25mm). Thin-walled bushings require less interference to prevent distortion. We can calculate optimal interference based on your specific application and provide h6 or h7 OD tolerance to achieve the desired press fit.

Yes, we can manufacture split bushings (also called split sleeves) for applications where disassembly would be difficult with solid bushings. Split bushings are typically cut with a single axial split and can be opened slightly for installation over a shaft. They're commonly used for retrofit applications or where frequent maintenance is required. However, split bushings have reduced load capacity compared to solid bushings and may require external retention features.

Lead times vary based on complexity and quantity. Simple bushings and spacers from standard materials can typically be completed in 1-2 weeks. Complex designs with special features (grooves, flanges, special materials) typically require 2-3 weeks. High-volume production runs may require 3-4 weeks for initial setup but then run continuously. Rush services are available for urgent requirements.

Yes, for aerospace applications we provide complete material traceability including material test reports (MTR), Certificate of Conformance (C of C), and AS9102 First Article Inspection Reports when required. All materials are sourced from certified suppliers with documented chain of custody. We can also provide additional testing such as hardness verification, chemical composition analysis, and dimensional reports as specified.