Technical Foundation
What Is a Mounted Linear Bearing?
A mounted linear bearing pairs a ball- or roller-recirculating linear bushing with a pre-machined housing (pillow block for top or side mounting, flange for end mounting through a bulkhead), letting an engineer bolt the assembly directly to a frame instead of machining a custom bore to press-fit a bare bushing. Housing style is chosen for the mounting geometry available — pillow block housings mount from above onto a flat surface with the shaft running through the block, while flange housings (round or square face) mount from the side, with the shaft passing through a flange face, suited to bulkhead or end-plate mounting.
Self-aligning (open or ball-and-socket style) housings accommodate minor shaft misalignment without binding, which matters on longer shaft runs or less rigid frames, while rigid (closed type) housings hold precise alignment but require the mounting surface and shaft to be accurately parallel to avoid binding and premature wear. Load rating must account for both radial load (supporting weight perpendicular to the shaft) and moment load (torque from an off-center or cantilevered load), since a bearing rated adequately for radial load alone can still fail prematurely under an unaccounted moment load.
Prefer a quick quote?
Get Mounted Linear Bearings Pricing in Your Inbox
Skip the search — tell us the shaft diameter, mount style and load direction (radial/moment) and we will come back with pricing.
| Spec | What It Means | Why It Matters |
|---|---|---|
| Mount Style | Pillow block, flange (round/square), twin bore | Determined by available mounting geometry — top-mount frame vs. bulkhead/end-plate mount |
| Shaft Diameter | Matched to the linear shaft, commonly 8mm–50mm / 1/4"–2" | Bearing bore must match the shaft precisely — undersized bore binds, oversized adds play |
| Alignment Type | Rigid (closed) vs. self-aligning (open/ball-socket) | Self-aligning tolerates minor shaft misalignment; rigid requires precise parallel mounting |
| Load Rating | Radial load and moment load capacity, separately rated | A bearing adequate for radial load alone can still fail under unaccounted moment/cantilever load |
| Bearing Type | Ball recirculating vs. roller recirculating | Roller types generally handle higher load and stiffness; ball types run smoother at lower load |
Shop Mounted Linear Bearings
Browse Mounted Linear Bearings Sub-Categories
Organised by mount style. Pick a sub-category, or describe the shaft diameter and mounting orientation and let ChatMRO match the bearing.
How it works
From Half-Remembered Part Number to PO, in Three Steps.
Ask
Type an MPN, paste a spec sheet, or describe the part in plain English. ChatMRO understands engineer-speak.
Compare
Side-by-side specs, cross-references, and equivalents from multiple sources — without the clutter of endless browser tabs.
Quote & Buy
Request a quote or add to cart. Volume discounts, VAT-aware pricing, and consolidated procurement — all in one place.
Applications
Where Mounted Linear Bearings Get Used
Mounted linear bearings are specified anywhere a shaft-guided linear motion axis needs a bolt-in support bearing without machining a custom housing.
Automation & Robotics Linear Axes
Mounted linear bearings supporting shaft-guided linear motion axes on pick-and-place and automation equipment.
CNC & Machine Tool Guideways
Pillow block linear bearings supporting precision-guided axes on machine tool and gantry systems.
Packaging Machinery
Linear bearing assemblies guiding reciprocating motion on packaging and converting equipment.
Material Handling & Conveyor Systems
Flange and pillow block bearings supporting linear positioning mechanisms on conveyor and sortation equipment.
Medical & Laboratory Automation
Precision linear bearing housings supporting compact, repeatable motion axes in lab automation equipment.
FAQ
Mounted Linear Bearings Questions, Answered
How do I choose between a pillow block and a flange mount linear bearing?
The choice comes down to available mounting geometry: a pillow block mounts from above (or the side) onto a flat frame surface, with the shaft passing horizontally through the block, and is the more common choice for open frame designs. A flange mount bolts through a bulkhead or end plate with the shaft passing through the flange's center bore, which suits designs where the mounting surface is a vertical panel or wall rather than a flat top surface.
What's the difference between a rigid and a self-aligning linear bearing housing?
A rigid (closed type) housing holds the bearing fixed and requires the mounting surface and shaft to be precisely parallel, since any misalignment translates directly into binding and uneven wear. A self-aligning (open or ball-and-socket style) housing allows the bearing element to pivot slightly within the housing, accommodating minor shaft misalignment or frame deflection without binding — useful on longer shaft spans or less rigid mounting structures where perfect alignment is hard to guarantee.
Why does moment load matter separately from radial load capacity?
Radial load is the straightforward weight or force pushing perpendicular to the shaft, but moment load accounts for the torque effect created when that load is applied off-center from the bearing (cantilevered), which stresses the bearing differently and can cause premature wear or failure even if the radial load alone is well within the rated capacity. Any design with an offset or cantilevered load on the linear axis needs to check moment load rating specifically, not just radial capacity.
Can I mix a ball-recirculating and roller-recirculating bearing on the same shaft axis?
It's not typical practice — ball and roller recirculating bearings have different load, stiffness, and precision characteristics, and mixing types on the same axis (even if physically compatible with the shaft diameter) can create uneven load distribution and motion characteristics between the two ends of the carriage. Best practice is to use matched bearing types throughout a single linear axis.
What shaft tolerance is needed for a mounted linear bearing to perform properly?
Linear shafting used with recirculating ball or roller bearings typically needs to meet a specific hardness and diameter tolerance (commonly h6 or similar precision ground tolerance class) since the bearing's recirculating elements ride directly on the shaft surface. Using undersized, out-of-round, or insufficiently hardened shaft stock can cause premature bearing wear or binding regardless of how well the housing itself is selected and mounted.
Keep browsing
Related Categories
Explore More
Find Your Next Part Now.
Describe a part number, spec or what it does.