Compact Shaft Support for Tight Mounting Spaces

Restricted mounting space often calls for a compact bearing unit that can support the shaft without requiring the footprint of a larger flange housing. Timken Fafnir & U Series two-bolt flange units combine a mounted ball bearing with a two-point flange housing, giving maintenance teams an assembled bearing solution that can be secured directly to the supporting structure.

For maintenance involving the bearing itself, Timken Ball Bearings provides a related bearing pathway. When an existing flange unit has lost its identification, Calipers (Digital / Manual) can assist with shaft diameter, housing dimensions, bolt-hole size & bolt-centre measurements.

Correct replacement depends on more than matching the shaft. Housing footprint, bolt spacing, locking method, bearing insert, seal arrangement, load rating & available mounting area all matter.

What Are Timken Two-Bolt Flanged Mounted Bearings?

Timken two-bolt flanged mounted bearings combine a ball-bearing insert with a housing designed to attach through two flange mounting points.

Unlike an unmounted bearing that requires a separate housing arrangement, a mounted unit brings the bearing & supporting housing together as an assembly.

Timken offers two-bolt flange configurations across both its Fafnir mounted ball bearing range & U Series mounted ball bearing range.

Depending on the exact series, locking arrangements can include:

► Eccentric locking collar
► Concentric locking collar
► Setscrew locking
► Adapter sleeve locking

Timken also identifies multiple housing & sealing configurations within the broader family.

The category can therefore appear under searches such as two-bolt flange bearing, 2-bolt flange bearing, flange mounted bearing, flanged bearing unit, two-bolt bearing housing, Timken Fafnir flange bearing & UCFL bearing.

These descriptions identify the general format. The complete Timken reference remains the preferred replacement identifier.

Why Choose Timken Two-Bolt Flanged Mounted Bearings?

The two-bolt format is particularly useful where a shaft needs support against a machine face or frame without the footprint of a larger flange arrangement.

Compact Mounting Where Space Is Restricted

Timken describes its U Series two-bolt flanged units as being primarily designed for applications where the available mounting area is restricted.

This makes the configuration relevant to compact conveyor frames, machinery panels, agricultural equipment & material-handling assemblies where surrounding components limit available space.

Bearing & Housing Supplied as an Assembly

Timken U Series two-bolt flange units are supplied assembled & ready for mounting.

This simplifies the relationship between the bearing insert & housing compared with sourcing those components independently.

The shaft, locking method & housing dimensions still need to correspond with the application.

Self-Aligning Housing Relationship

Timken U Series units use wide-inner-ring ball bearings with spherical outside diameters that allow the bearing insert to align within the housing.

This feature can accommodate applicable initial shaft misalignment within the mounted-bearing design.

It should not be treated as permission to ignore significant machine alignment problems.

Multiple Shaft-Locking Methods

Not every Timken two-bolt flange bearing secures to the shaft in the same way.

The available Timken families include setscrew, eccentric collar, concentric collar & adapter-sleeve arrangements.

Matching the existing locking system can be just as important as matching the housing.

Relubrication Capability on Applicable Units

Timken identifies grease fittings for relubrication on applicable U Series mounted bearing units.

Maintenance requirements should follow the exact bearing series, operating conditions & lubrication guidance rather than applying one grease interval to every flange bearing.

Common Applications

Two-bolt flange bearings suit machinery where the shaft passes through or terminates near a structural face & a compact mounting pattern is desirable.

Conveyor Shafts

Conveyors are a natural application for flange-mounted bearing units because shafts frequently need support at the side of a conveyor frame.

A two-bolt housing can provide a compact footprint while keeping the bearing accessible for inspection & replacement.

When a conveyor bearing repeatedly fails, investigate alignment, shaft condition, contamination, loading & surrounding drive components before simply installing another unit.

Agricultural Machinery

Timken's Fafnir mounted bearing range includes configurations relevant to agricultural equipment.

Farm machinery repairers should preserve the complete unit reference because two housings that look similar can differ in shaft size, bearing insert, collar, seal & mounting dimensions.

Material-Handling Equipment

Rollers, transfer equipment & other material-handling systems can require mounted bearings positioned against relatively narrow structural members.

Material Handling Equipment provides a relevant pathway into the broader equipment environment where mounted bearing systems may operate.

Fans & Driven Equipment

A two-bolt flange arrangement can support shafts in suitable fan, drive & rotating-equipment designs.

The bearing must still be selected around actual radial & axial loading, speed, shaft size & environmental conditions.

Compact Machinery Frames

Equipment builders can use two-bolt flange units where the available mounting face makes a four-bolt housing unnecessarily large or impractical.

Housing dimensions should be treated as part of the machine design rather than something to resolve after the bearing has been selected.

Product Selection Guide

A reliable replacement process starts with the existing unit then works through shaft, housing & operating requirements.

Record the Complete Timken Part Number

Preserve every letter, number & suffix visible on the existing unit.

Timken Fafnir examples include references such as:

► FLCT 1/2
► FLCT 30
► FLCT 35
► RCJT 1/2
► YCJT 1/2
► RCJTC 5/8

Timken U Series families include:

► UCFL 200
► UCFL 300
► UELFL 200
► UKFL 200

The series letters contain useful information about the mounted-bearing family & locking arrangement. Do not reduce a purchasing request to “two-bolt bearing”.

Confirm Shaft Size

The bearing bore must correspond with the shaft.

Timken's two-bolt flange portfolio includes both inch & metric shaft sizes across applicable series.

Where markings cannot be read, measure the shaft accurately rather than estimating from the housing.

Measure the Mounting Footprint

A shaft-size match does not guarantee that the replacement housing will bolt onto the machine.

Confirm:

► Total housing length
► Total housing height
► Housing width
► Bolt-hole spacing
► Bolt-hole diameter
► Available clearance around the flange

For example, Timken's FLCT 30 uses a 30 mm shaft size with 90.5 mm bolt-hole spacing while FLCT 35 uses a 35 mm shaft with 100 mm bolt-hole spacing.

That dimensional change matters when the replacement must return to an existing machine frame.

For broader dimensional inspection Measuring & Layout Tools provides useful workshop measuring options.

Identify the Shaft-Locking Method

The locking arrangement should be confirmed before ordering.

A similar-looking housing with a different locking system should not automatically be treated as an equivalent replacement.

Check the Bearing Insert

The housing reference can lead to the bearing insert used inside the assembly.

For example, Timken identifies:

► FLCT 1/2 with RA008RRB bearing
► FLCT 30 with RAE30RRB bearing
► FLCT 35 with RAE35RRB bearing

Recording the insert can be valuable when troubleshooting an existing assembly or confirming the correct replacement.

Confirm Seal Type

Timken two-bolt flange units are available with different sealing arrangements depending on series.

Examples within the Fafnir range include moulded shroud & shroud seal configurations.

The seal is part of the bearing specification & should be considered alongside contamination exposure rather than selected from housing appearance alone.

Compare Load Ratings

Timken publishes static & dynamic load ratings for individual mounted-bearing references.

For example, FLCT 30 is listed with a 11,300 N static load rating & 21,600 N dynamic load rating while FLCT 35 is listed at 15,300 N static & 28,500 N dynamic.

These figures illustrate why shaft size alone cannot determine application suitability.

Use the ratings for the exact bearing reference when assessing a replacement.

Expert Tips

Measure Bolt Centres Before Removing the Old Housing

The distance between mounting holes is one of the quickest ways to prevent an incorrect flange unit reaching the machine.

Record the centre-to-centre dimension before dismantling the assembly.

Do Not Use Housing Shape as the Only Identifier

Two Timken units can both have a two-bolt flange while using different locking systems, bearing inserts, seals or mounting dimensions.

The housing silhouette identifies the general family rather than the exact replacement.

Inspect the Shaft Where the Bearing Locks

Setscrews, collars & adapter sleeves interact with the shaft differently.

Look for fretting, scoring, wear or previous locking marks before fitting another bearing.

A damaged shaft can undermine the performance of a correctly selected mounted unit.

Treat Repeated Loosening as a Diagnostic Clue

If a bearing repeatedly moves on the shaft, determine why.

Possible contributors include:

► Incorrect locking method
► Improper installation
► Shaft wear
► Incorrect shaft diameter
► Excessive vibration
► Misalignment
► Unexpected loading

Replacing the same unit without investigating the cause can reproduce the same failure.

Verify Alignment Across the Complete Shaft

Self-aligning characteristics within a mounted-bearing housing can accommodate applicable initial misalignment but they are not a substitute for correctly positioned machinery.

Check the relationship between opposing bearings, shafts, pulleys, sprockets & driven components.

Workshop Equipment provides supporting equipment for wider machinery maintenance & rebuild work.

Keep Mounting Faces Clean & Flat

Rust scale, weld spatter, burrs or trapped debris behind the flange can affect how the housing seats against the machine.

Inspect & prepare the mounting surface before tightening the housing bolts.

Inspect Mounting Hardware During Bearing Replacement

A new mounted bearing deserves sound mounting hardware.

Check bolt threads, fastener condition, holes & supporting structure rather than automatically reusing components that have been through repeated service cycles.

Bolts & Fasteners provides a relevant supporting category when the wider mounting assembly requires attention.

Record Bearing Position on Multi-Shaft Machinery

A conveyor or processing machine may use several visually similar mounted bearings with different shaft sizes or housing dimensions.

Record each Timken reference against its exact machine position.

A practical asset record includes:

► Timken mounted-bearing reference
► Bearing insert reference where known
► Shaft diameter
► Bolt-centre spacing
► Locking method
► Seal configuration
► Machine position
► Installation date

For maintenance teams responding to unexpected equipment failures Emergency Worksite Breakdown Support provides broader guidance around breakdown preparation & response.

Preventive inspections can also identify loose housings, contamination & developing bearing noise before production is interrupted. Spring Jobsite Prep Getting Your Gear Ready provides additional equipment-preparation guidance.