Technical Foundation
What Is a Sleeve Bearing?
A sleeve bearing (plain or journal bearing) is a simple cylindrical bushing that supports a rotating or oscillating shaft through direct sliding contact rather than rolling elements like a ball or roller bearing. The bearing's inner bore diameter is sized to the shaft with a controlled running clearance, and a lubricant film — whether externally supplied, held within the bearing's porous structure, or built into a self-lubricating polymer matrix — separates the two surfaces to reduce friction and wear.
Oil-impregnated sintered bronze bearings (commonly SAE 841 grade) are manufactured from powdered metal pressed and sintered to a controlled porosity, then vacuum-impregnated with oil that migrates to the bearing surface under the heat and pressure of shaft rotation — giving useful service without any external lubrication schedule in low-to-moderate speed applications. Self-lubricating polymer bearings (PTFE-lined or filled composites) go further, running dry indefinitely and resisting the contamination and wash-out issues that make oil or grease unsuitable in food, washdown or dirty environments. Solid bronze and cast bearings, by contrast, need externally applied lubrication but tolerate higher loads and temperatures than either alternative.
Prefer a quick quote?
Get Sleeve Bearings Pricing in Your Inbox
Skip the search — tell us the bore diameter, shaft speed and load and we will come back with pricing.
| Spec | What It Means | Why It Matters |
|---|---|---|
| Bore Diameter & Fit | Sized to shaft with controlled running clearance | Too tight causes seizure under thermal expansion; too loose causes vibration and wear |
| Material | Sintered bronze, solid bronze, polymer/PTFE-lined | Determines load capacity, speed range and whether external lubrication is required |
| Lubrication Type | Self-lubricating (impregnated/polymer) vs. externally lubricated | Self-lubricating suits inaccessible or maintenance-free installations |
| Load Rating (PV value) | Pressure-velocity limit for the material | Exceeding PV rating causes accelerated wear or lubricant breakdown |
| Flange/Style | Plain sleeve vs. flanged | Flanged bearings also take axial thrust load and locate the bearing in the housing bore |
Shop Sleeve Bearings
Browse Sleeve Bearings Sub-Categories
Organised by material and lubrication method. Pick a sub-category, or describe the shaft bore, speed and load.
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 Sleeve Bearings Get Used
Sleeve bearings are specified wherever moderate speed, radial-load shaft support is needed at lower cost or in tighter space than a rolling-element bearing allows.
Conveyor & Material Handling Equipment
Low-speed, high-radial-load shaft support on rollers, pulleys and idler shafts.
Pump & Motor Shaft Support
Sleeve bearings supporting rotating shafts in general-purpose pumps and fractional-horsepower motors.
Food & Beverage Processing Equipment
Self-lubricating polymer bearings specified where washdown and contamination rule out grease-lubricated bearings.
Agricultural & Off-Road Equipment
Oil-impregnated sintered bronze bushings in linkages and pivot points exposed to dirt and infrequent maintenance.
Office & Consumer Equipment
Small-bore self-lubricating bearings in printers, appliances and light-duty rotating mechanisms.
HVAC Fan & Blower Shafts
Sleeve bearings supporting low-speed fan and blower shafts in commercial HVAC equipment.
FAQ
Sleeve Bearings Questions, Answered
What's the difference between a sleeve bearing and a ball bearing?
A sleeve bearing supports the shaft through direct sliding contact across a lubricant film, with no rolling elements — it's simpler, cheaper, quieter, and tolerant of shock loads, but generally has a lower speed limit and higher friction than a ball or roller bearing, which uses rolling elements to reduce friction and support higher speeds and precision.
What does oil-impregnated sintered bronze mean, and when should I use it?
Sintered bronze bearings are made from powdered bronze pressed and sintered to a controlled porous structure, then vacuum-impregnated with oil that's held within the pores and migrates to the running surface under shaft rotation. This gives self-lubricating operation without an external lubrication schedule, making it a common choice for low-to-moderate speed, moderate-load applications where routine greasing isn't practical.
When should I choose a self-lubricating polymer bearing over bronze?
Polymer (often PTFE-lined or filled composite) bearings run dry and resist contamination, washdown and chemical exposure that would flush oil out of a sintered bronze bearing or attract debris into a greased one — food processing, washdown equipment, and dirty outdoor environments are typical applications. They generally carry lower load and temperature ratings than metal bearings, so check the PV (pressure-velocity) rating against the application.
What is PV rating and why does it matter for sizing a sleeve bearing?
PV (pressure times velocity) is the standard way bearing materials rate their load-speed capability, since a sleeve bearing can fail either from too much load at low speed or from heat buildup at high speed even under light load. Calculate the application's actual pressure (load ÷ projected bearing area) and surface velocity, then confirm it falls under the material's rated PV limit.
How much clearance should there be between the bearing bore and the shaft?
Running clearance needs to be tight enough to control vibration and maintain the lubricant film geometry, but loose enough to accommodate thermal expansion of the shaft and bearing during operation without seizing. Manufacturers publish recommended bore tolerances for each bearing size and material — undersized clearance is a common cause of premature seizure in sintered and polymer bearings especially.
Keep browsing
Related Categories
Explore More
Find Your Next Part Now.
Describe a part number, spec or what it does.