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

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.

LMFC/LMKC...UU flanged linear bearing product view

⚙ 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
LMFC/LMKC...UU dimensional specification drawing

🔭 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.

LMFC/LMKC...UU linear bearing in industrial application

🔧 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.

LMFC/LMKC...UU linear bearing assembly and housing

❓ Frequently Asked Questions

▶ What is the function of the locking screw on LMFC/LMKC/LMEFC/LMEKC bearings?

The external locking screw compresses the split outer ring slightly, reducing the bore diameter and creating a light interference fit on the shaft. This eliminates radial clearance without changing the housing bore and allows the user to set the exact preload level in the field using only a screwdriver or hex key.

▶ How much preload should I apply with the locking screw?

Start at zero clearance (screw tightened until resistance is felt, then backed off one-eighth turn) and increase preload in small increments while checking shaft travel resistance. Excessive preload increases friction and heat, shortening bearing life. The correct preload is the minimum that eliminates detectable play in the application.

▶ Can the locking screw be retightened after a period of use?

Yes. If the shaft develops play during service (detectable as radial looseness when the shaft is pushed laterally), tighten the locking screw incrementally until play is eliminated. This extends bearing service life by compensating for ball-track wear without requiring bearing replacement.

▶ Is the LMFC/LMEFC round flange or LMKC/LMEKC diamond flange preferred for locking-screw applications?

The choice follows the same logic as standard flanged bearings: LMFC/LMEFC for maximum moment resistance and even bolt-load distribution; LMKC/LMEKC for compact installations where flange radius is constrained. The locking-screw function is identical in both variants.

▶ What is the operating temperature range?

Standard supply with NBR seals and lithium-complex NLGI-2 grease: −20°C to +80°C continuous. For elevated temperatures up to 120°C, specify high-temperature grease and FKM (Viton) seals. Contact GBC for custom configurations outside this range.

📞 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.

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