LMFC LMKC Linear Bearing UU Series — Flanged Sealed Ball Bushing with Locking Screw
LMFC/LMKC…UU flanged recirculating linear ball bearing series — ISO Flanged with Locking Screw. 13 bore sizes. Dynamic load 323–7550 N. GCr15 HRC 58–64, dual lip seals, flanged housing mount.
MOQ: 50 pcs. Minimum order value USD 1,500; mixed orders and trial quantities welcome.
Linear Bearings › Flanged Series › ISO Flanged with Locking Screw
LMFC LMKC Linear Bearing UU Series — Flanged Sealed Ball Bushing with Locking Screw
13 bore sizes • Dynamic load 323–7550 N • ISO Flanged with Locking Screw
GCr15 HRC 58–64
Flanged Mount
Dual Lip Seal
🆕 Series Overview
The LMFC/LMKC...UU series incorporates an external locking screw that compresses the split outer ring to reduce internal radial clearance or apply a defined preload after installation. This allows field adjustment without housing modification, enabling users to compensate for tolerance stack-up and restore zero-clearance operation as the bearing wears. Round-flange (LMFC) and diamond-flange (LMKC) configurations share the same bore and body dimensions.
The locking screw acts on a split in the outer ring, reducing bore diameter uniformly when tightened. Starting from normal-clearance condition, incremental tightening reduces clearance through zero to a controlled preload. This adjustability is valuable in precision positioning systems — optical stages, semiconductor handlers, medical drives — where zero backlash is required and clearance must be periodically reset as wear accumulates.

⚙ Key Design Features
Flanged Axial Location
The precision-ground flange face registers directly against the housing shoulder, providing positive axial location without snap rings or adhesive retention.
GCr15 Chrome Steel
Through-hardened to HRC 58–64. Ball tracks ground to Ra 0.2 µm for full-film lubrication at the ball-race contact under rated load conditions.
Dynamic Load 323–7550 N
Covering 13 bore sizes for applications from lightweight instrument stages to heavy industrial press guides.
NBR Dual Lip Seals
Retain factory-applied NLGI-2 grease while excluding dust and contamination. Rated −20°C to +80°C continuous service.
PA66-GF30 Retainer
Glass-filled nylon cage maintains precise ball spacing across the full 360° circuit, preventing ball-to-ball contact and associated noise.
ISO/DIN Interchangeable
All dimensions conform to ISO Flanged with Locking Screw standards for direct replacement compatibility with equivalent housings.
📋 Complete Specification Table
ⓘ Dynamic load rating C based on 50 km nominal life (L10). For 100 km design life, divide C by 1.26. Shaft h6/h7. Housing H7. All dimensions in mm, load ratings in N, weight in g.
| LMFC Model | LMKC Model | Bore dr | OD D | Length L | H mm | PCD mm | Ball Cir. | Dyn C (N) | Sta Co (N) | Wt (g) | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| LMFC6UU | LMKC6UU | 6 | 12 | 35 | 15 | 20 | 22 | 4 | 323 | 529 | 31 |
| LMFC8UU | LMKC8UU | 8 | 15 | 45 | 20 | 24 | 32 | 4 | 431 | 784 | 51 |
| LMFC10UU | LMKC10UU | 10 | 19 | 55 | 24.5 | 30 | 40 | 4 | 588 | 1100 | 98 |
| LMFC12UU | LMKC12UU | 12 | 21 | 57 | 25.5 | 32 | 42 | 4 | 813 | 1570 | 110 |
| LMFC13UU | LMKC13UU | 13 | 23 | 61 | 27.5 | 34 | 43 | 4 | 813 | 1570 | 130 |
| LMFC16UU | LMKC16UU | 16 | 28 | 70 | 32 | 37 | 48 | 5 | 1230 | 2350 | 190 |
| LMFC20UU | LMKC20UU | 20 | 32 | 80 | 36 | 42 | 54 | 5 | 1400 | 2740 | 260 |
| LMFC25UU | LMKC25UU | 25 | 40 | 112 | 52 | 52 | 62 | 6 | 1560 | 3140 | 540 |
| LMFC30UU | LMKC30UU | 30 | 45 | 123 | 56.5 | 60 | 74 | 6 | 2490 | 5490 | 680 |
| LMFC35UU | LMKC35UU | 35 | 52 | 135 | 62.5 | 67 | 82 | 6 | 2650 | 6270 | 1020 |
| LMFC40UU | LMKC40UU | 40 | 60 | 151 | 69 | 75 | 96 | 6 | 3430 | 8040 | 1570 |
| LMFC50UU | LMKC50UU | 50 | 80 | 192 | 89.5 | 92 | 116 | 6 | 6080 | 15900 | 3600 |
| LMFC60UU | LMKC60UU | 60 | 90 | 209 | 95.5 | 106 | 134 | 6 | 7550 | 20000 | 4500 |

🔭 Materials & Construction
GCr15 chrome steel (AISI 52100), HRC 58–64. The split outer ring is ground after hardening to maintain bore roundness in the free (unlocked) condition. Tightening the locking screw produces controlled elastic deformation — the screw can be backed off to restore normal clearance at any point. PA66-GF30 retainer. NBR seals. NLGI-2 grease. Range −20°C to +80°C.
The ball retainer is injection-moulded from glass-fibre-reinforced nylon (PA66-GF30), maintaining precise ball spacing around the full 360° circuit to prevent ball-to-ball contact noise at higher traverse speeds. Dual NBR lip seals on both end faces retain factory-applied NLGI-2 lithium-complex grease while excluding dust, swarf, and splash contamination. Operating temperature range is −20°C to +80°C with standard seals and grease.
🏭 Typical Applications
CNC Machining Centres
Flanged linear bearings provide a positive axial stop against the housing shoulder, eliminating the need for snap rings in high-speed spindle carriage and tool-change axis applications where axial retention under reversal loads is critical.
Optical & Metrology Equipment
LMF round-flange bearings in microscope focus drives and spectrometer sample stages provide sub-micron runout between the bore and flange face, ensuring that the optical axis remains aligned when the bearing is replaced without re-calibration.

🔧 Installation & Maintenance
🔎 Flange Face Seating
Ensure the housing counterbore depth matches the bearing flange thickness. An under-depth counterbore leaves the flange proud of the housing face, creating a gap at the bolt interface that allows the bearing to rock under load and introduces harmonic error motion.
🔧 Bolt Torque Sequence
Tighten flange mounting bolts in a cross pattern to 30–50% of final torque, then complete to specification. Sequential tightening distorts the flange and shifts the bore axis by up to 0.05 mm, degrading shaft alignment.
📈 Lubrication
Apply NLGI-2 lithium-complex grease to the shaft before insertion. Re-lubricate every 500 km of travel or 6 months under normal duty. In washdown environments, shorten the re-lubrication interval and use a water-resistant grease formulation.
⚙ Locking Screw Torque (FC/KC variants)
For LMFC/LMKC/LMEFC/LMEKC bearings, tighten the external locking screw to finger-tight plus one-quarter turn after positioning the bearing axially. Over-tightening distorts the outer race and increases running friction; under-tightening allows axial creep under dynamic loads.
🔎 Selection Guide
Specify LMFC/LMKC when zero-backlash or defined-preload guidance is required and field adjustability is valued. Calculate the friction force added by preload and verify the drive actuator can overcome it at all operating speeds. Do not apply preload beyond the point where shaft traverse becomes noticeably stiff.
①
Confirm Bore & Standard
Match bore diameter to shaft. Confirm ISO Flanged with Locking Screw housing dimensions — mixing ISO and DIN outer diameters requires housing re-machining.
②
Select Flange Style
Round flange for maximum moment resistance; diamond flange for compact bolt clearance; square flange for torsional resistance.
③
Calculate Load & Life
Compute radial load P. Target L10 = (C/P)³ × 50 km. If life is marginal, specify the LUU extended variant to raise C without changing bore.
④
Contact Us
MOQ 100 units per model. Contact our team with engineering drawings confirming shaft diameter, housing bore depth, bolt PCD, load case, and target life.

❓ Frequently Asked Questions
📞 Ready to Order?
MOQ is 100 units per model. Provide engineering drawings with shaft diameter, housing bore depth, flange PCD, load case, stroke, speed, and target life. All catalogue data is for reference only — verify critical dimensions against current revision drawings before committing to tooling.
LMFC/LMKC…UU flanged recirculating linear ball bearing series — ISO Flanged with Locking Screw. 13 bore sizes. Dynamic load 323–7550 N. GCr15 HRC 58–64, dual lip seals, flanged housing mount.
MOQ: 50 pcs. Minimum order value USD 1,500; mixed orders and trial quantities welcome.





