Dongfeng Bearing
LMUU Series Sealed Extended-Length Linear Bearing
LMUU Series sealed extended-length linear bearing with double-lip rubber seals and labyrinth groove, reducing dust ingress by 95% versus open-type bearings. Extended sleeve increases ball count by 40%, delivering 1,580 N dynamic load at LM16UU. Designed for woodworking CNC, stone cutting, and recycling machinery in contaminated environments.
Key Features
- Double-lip NBR rubber seal + labyrinth groove reduces dust ingress by 95% versus open-type LM bearings
- Extended sleeve body increases ball count by 40%, distributing load and extending travel life proportionally
- 1,580 N dynamic load at LM16UU with 2,450 N static load — higher than standard LM due to more ball contacts
- NBR seals operate -30°C to +110°C; FKM (Viton) option available for high-temperature applications up to 200°C
- JIS B 1185 LM envelope outer diameter — drops into standard LM housings without modification
- In-house seal molding capability ensures consistent seal quality and enables custom compounds for high-volume orders
Common Sourcing Problems & How We Solve Them
Buyer Pain Points
- Inconsistent dimensional tolerances across batches cause machine downtime and re-work costs
- Suppliers unable to provide material certs, inspection reports or CE documentation for customs clearance
- Long lead times and high MOQ requirements make sample evaluation and first orders difficult
Dongfeng Solution
- ISO 9001:2015 process controls with CMM dimensional inspection on every production batch
- Full documentation package: material cert, SGS test report, CE declaration, packing list on request
- Flexible MOQ from 1 piece for samples; bulk order lead time 15–20 working days
Performance Data
- 10+ years of linear motion component manufacturing — 50+ export markets served
- Hardness tested to HRC 58–62; dimensional tolerance held to JIS / ISO / DIN standard grade
- CE & SGS certified; ISO 9001:2015 quality management system in production
Utility record
| Bearing Series | LMUU 6–60 (11 sizes) |
|---|---|
| Seal Type | Double-lip NBR rubber + labyrinth groove |
| Outer Ring Material | Chrome Steel GCr15 (52100) |
| Ball Material | Chrome Steel GCr15 |
| Retainer | PA66-GF Glass-Fiber Nylon |
| Shaft Diameter | 6 mm – 60 mm |
| Dynamic Load (LM16UU) | 1,580 N |
| Static Load (LM16UU) | 2,450 N |
| Sleeve Length (LM16UU) | 35 mm (extended) |
| Seal Temp Range | -30°C to +110°C (NBR) |
Application fit notes
User Pain Point + Solution + Data
Automation equipment operating in dusty factory environments — woodworking CNC, stone cutting, and recycling machinery — faces a persistent problem: abrasive dust infiltrates open-type linear bearings, contaminates the ball circuit, and causes premature raceway pitting within weeks. The LMUU sealed extended bearing addresses this with a double-lip rubber seal system on both ends, an extended sleeve body that increases the ball count by 40%, and a labyrinth seal groove between the seal and ball entry zone. The result: dust ingress reduced by 95% versus open-type LM bearings, and dynamic load capacity reaching 1,580 N at LM16UU with a 40% increase in rated travel life in contaminated environments.
Complete Specifications
| Parameter | Value |
|---|---|
| Bearing Series | LMUU 6 / 8 / 10 / 12 / 16 / 20 / 25 / 30 / 40 / 50 / 60 |
| Seal Type | Double-lip rubber seal + labyrinth groove (both ends) |
| Outer Ring Material | Chrome Steel GCr15 (52100 equiv.) |
| Ball Material | Chrome Steel GCr15 |
| Retainer Material | PA66-GF Glass-Fiber Nylon |
| Shaft Diameter Range | 6 mm – 60 mm |
| Dynamic Load (LM16UU) | 1,580 N |
| Static Load (LM16UU) | 2,450 N |
| Sleeve Length (LM16UU) | 35 mm (vs 24 mm standard) |
| Seal Temperature Range | -30°C to +110°C (NBR rubber) |
| Standard Reference | JIS B 1185 LMUU (sealed extended) |
Product Advantages
Double-Lip Sealing System
Two NBR rubber lips per seal contact the shaft at different angles, creating a primary wiping lip (removes debris) and a secondary sealing lip (retains grease). The labyrinth groove between the seal and ball entry adds a tortuous path that stops fine dust from reaching the ball circuit.
95% Dust ReductionExtended Ball Circuit
Sleeve body is 40% longer than standard LM, accommodating 40% more recirculating balls. This distributes load across more contact points, reducing per-ball stress and extending travel life proportionally under equivalent loads.
+40% Ball CountNBR Seal for Wide Temp Range
Nitrile rubber seals operate from -30°C to +110°C, covering most industrial environments including refrigerated packaging lines and warm woodworking shop interiors. FKM (Viton) seals available for high-temperature applications up to 200°C.
-30 to +110°CPress-Fit Compatibility
Outer diameter follows JIS B 1185 LM envelope dimensions. The extended sleeve drops into standard LM housings without modification — the longer body simply extends beyond the housing face, providing additional load support.
JIS Drop-InEnterprise Strength
Xiamen Dongfeng Bearing Mechanical & Electrical Co., Ltd.Ltd. — established 2014, 10+ years in linear motion bearing manufacturing. Our 5,000 m² Xiamen facility operates 12 production lines with 200+ employees. The sealed bearing cell produces LMUU series at 80,000+ pieces per month, with in-house seal molding capability for both NBR and FKM compounds.
Certifications: ISO 9001:2015, CE conformity, SGS factory audit. Export markets: 50+ countries including Germany, Italy, USA, India, Turkey, and Brazil. Partners: Supplying woodworking CNC manufacturers, stone processing equipment builders, and recycling machinery OEMs.
Pre-sales: Dust environment assessment and seal material recommendation (NBR vs FKM). After-sales: 18-month warranty, seal replacement technical support. Customer case: Supplied 18,000 LM16UU sealed bearings to an Italian woodworking CNC manufacturer — average service life 18 months in high-dust environment where open-type bearings previously failed within 6 weeks.
Manufacturing, Exhibition & Quality Controltrol
Production Process & Quality Assuranceance
Process: GCr15 raw tube → CNC turning (extended sleeve, raceway groove, seal groove) → induction hardening (HRC 60–64) → precision grinding (raceway) → in-house NBR seal molding → ball circuit assembly with PA66-GF retainer → double-lip seal press-fit → 100% dust ingress test → packaging.
Quality testing: Seal effectiveness validated using ISO 20643 dust ingress test (8-hour talc powder exposure), dynamic load on endurance rig (1,200 km travel at rated load in dusty environment), seal lip force measured per batch (0.5–2.0 N range). Exhibitions: Exhibited at LIGNA (woodworking machinery, Hannover), XYLEMPO (stone processing, Verona), and IFAT (recycling, Munich) to reach harsh-environment equipment manufacturers.
FAQ
What is the MOQ for LMUU sealed bearings?
MOQ is 100 pieces per size. Mixed sizes accepted with 100-piece minimum per individual size. For high-volume orders (5,000+ pieces), custom seal color or material can be specified. Sample quantities of 10–20 pieces available for qualified buyers.
What are the shipping options and typical lead time?
FOB Xiamen. In-stock sizes (LMUU6–LMUU30): 7–10 business days. Larger sizes (LMUU40–LMUU60): 15–20 business days. Express courier (DHL/FedEx): 5–7 days for samples. Sea freight: 25–35 days to Europe, 18–25 days to USA. Air freight available for urgent orders.
How are LMUU bearings packaged for export?
Individual anti-corrosion oiled wrapping in plastic bags, then packed in partitioned cartons (50 pieces per carton for LMUU6–LMUU20, 25 pieces for LMUU25–LMUU40, 10 pieces for LMUU50–LMUU60). Export-grade wooden pallet packing available for bulk shipments. Custom packaging per buyer requirements accepted.
What payment methods do you accept?
T/T (30% deposit, 70% before shipment) is standard. L/C at sight for orders above USD 15,000. PayPal for sample orders under USD 2,000. Western Union for small orders on request.
Can I get samples for testing in my dusty environment?
Yes. Sample quantities of 10–20 pieces per size are available with buyer covering shipping. We strongly recommend testing in your actual operating environment since dust characteristics vary significantly by industry. Sample cost is credited toward bulk orders of 500+ pieces.
Do you offer OEM branding and custom seal materials?
Yes. Custom laser-engraved logo on sleeve outer surface available for 200+ piece orders. FKM (Viton) seals for high-temperature applications available for 500+ piece orders. Custom seal colors and retainer materials can be discussed for high-volume orders — share your requirements and operating environment details.
Request a Quote for LMUU Sealed Bearings
Send your shaft diameter, operating environment (dust type, temperature), quantity, and any OEM requirements — we reply within one business day.
Request a QuoteWhy Buyers Choose Dongfeng Bearing
Xiamen Dongfeng Bearing Mechanical & Electrical Co., Ltd. — direct factory, 10+ years precision linear motion manufacturing
ISO 9001:2015, CE Declaration of Conformity, SGS test reports. Documentation available for EU and North American import requirements.
12 precision grinding and CNC machining lines; monthly output 500,000+ pieces across linear bearing and guideway series.
Germany, USA, Japan, South Korea, India, Southeast Asia and 40+ other countries. FOB Xiamen with DHL / FedEx / sea freight options.
Technical selection support before order. Dimensional drawing, material cert and inspection report with shipment. 12-month warranty on manufacturing defects.
Manufacturing Process & Quality Assurance
Precision Machining
CNC grinding centers hold ball raceway geometry to ±0.003 mm. Induction hardening targets contact zones to HRC 58–62 without embrittling the full body.
CMM Dimensional Inspection
Every batch passes coordinate measuring machine (CMM) verification. Key dimensions — bore, OD, length, raceway radius — are logged against JIS / ISO tolerance bands.
Certification & QC
ISO 9001:2015 controls govern raw material intake, in-process check, and final inspection. SGS and CE documentation issued on request for each shipment.
Trade Shows & Partnerships
Regular exhibitor at Canton Fair and Hannover Messe. Established supply partnerships with automation integrators and machine tool OEMs across Europe and Asia.
Customer Application Cases
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