Dongfeng Bearing
LMF Series Square Flange Linear Ball Bearing
LMF Series square-flange linear ball bearing with 4-bolt square mounting pattern for JIS B 1185 standard housings. GCr15 chrome steel with PA66-GF retainer delivers 1,370 N dynamic load at LMF16UU. Designed for CNC router, 3D printer, and automation frames using square aluminum extrusion housings.
Key Features
- Square 4-bolt flange mounts directly to aluminum extrusion T-slot plates — no press-fit tooling needed
- JIS B 1185 dimensional standard — interchangeable with THK, IKO, MISUMI, and NB equivalents
- UU-type double rubber seals prevent grease escape and dust entry, extending maintenance intervals
- GCr15 chrome steel outer ring and balls, hardened to HRC 60–64 for consistent load performance
- Shaft diameter range 6–50 mm covered in one product family
- H5 precision grade available on request for LMF8–LMF40 for measurement and positioning applications
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 | LMF 6–50 (10 sizes) |
|---|---|
| Flange Type | Square, 4-bolt diagonal |
| Outer Ring Material | Chrome Steel GCr15 |
| Ball Material | Chrome Steel GCr15 |
| Retainer | PA66-GF Glass-Fiber Nylon |
| Shaft Diameter | 6 mm – 50 mm |
| Dynamic Load (LMF16UU) | 1,370 N |
| Static Load (LMF16UU) | 2,160 N |
| Precision Grade | Normal / H5 |
| Standard Reference | JIS B 1185 LMF |
Application fit notes
User Pain Point + Solution + Data
The LME circular-flange bearing is standard for European machinery, but many Asian-built CNC routers, 3D printers, and automation frames use square aluminum extrusion housings that require a square-flange bearing for proper bolt-on mounting. The LMF Series fills this gap: a square flange with four equally spaced bolt holes, dimensionally compatible with JIS B 1185 LMF standard. The bearing body is GCr15 chrome steel with PA66-GF retainer and recirculating ball circuit, delivering 1,370 N dynamic load at LMF16UU. Shaft diameters from 6 mm to 50 mm are covered in a single product family.
Complete Specifications
| Parameter | Value |
|---|---|
| Bearing Series | LMF 6 / 8 / 10 / 12 / 16 / 20 / 25 / 30 / 40 / 50 |
| Flange Type | Square flange, 4-bolt pattern (diagonal) |
| 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 – 50 mm |
| Dynamic Load (LMF16UU) | 1,370 N |
| Static Load (LMF16UU) | 2,160 N |
| Precision Grade | Normal / H5 (on request) |
| Sealing | Double rubber seals (UU type) |
| Standard Reference | JIS B 1185 LMF |
Product Advantages
Square Flange for Extrusion Housings
Four-bolt square flange mounts directly to standard aluminum extrusion T-slot plates and square housing blocks used in Asian CNC router and 3D printer frames. No press-fit tooling or circular housing boring required — just bolt on.
4-Bolt SquareJIS B 1185 Interchangeable
LMF dimensions follow JIS B 1185 standard. Dimensionally interchangeable with THK, IKO, MISUMI, and NB square-flange linear bearings of the same size. Buyers can substitute directly without modifying the housing plate.
JIS StandardSealed for Clean Operation
UU-type double rubber seals on both ends prevent grease escape and block dust entry into the ball circuit. This extends re-lubrication intervals and reduces maintenance on CNC router and 3D printer axes that run in open environments.
UU SealedH5 Precision Option
Normal grade covers most automation applications. H5 precision grade (bore tolerance ±2 µm) is available on request for LMF8–LMF40, suitable for measurement equipment and precision positioning stages requiring tighter running accuracy.
H5 AvailableEnterprise Strength
Xiamen Dongfeng Bearing Mechanical & Electrical Co., Ltd.Ltd. — founded 2014, 10+ years manufacturing linear motion bearings. Our 5,000 m² Xiamen facility operates 12 production lines with 200+ employees. The linear bearing cell produces LM, LME, and LMF series at 120,000+ pieces per month, supplying both standard and custom configurations.
Certifications: ISO 9001:2015, CE conformity, SGS factory audit. Export markets: 50+ countries — strong presence in the USA, Germany, Netherlands, Japan, South Korea, and Australia. Partners: Supplying CNC router manufacturers, 3D printer OEMs, automation system integrators, and semiconductor equipment builders.
Pre-sales: CAD models and dimension tables available within hours. After-sales: 18-month warranty, technical selection guidance. Customer case: Supplied 30,000 LMF16UU bearings to a US-based CNC router manufacturer — 0.05% defect rate over 2-year supply, zero warranty claims related to flange failure.
Manufacturing, Exhibition & Quality Controltrol
Production Process & Quality Assuranceance
Process: GCr15 raw tube → turning (outer ring, flange, raceway groove) → induction hardening (HRC 60–64) → precision grinding (raceway) → ball circuit assembly with PA66-GF retainer → seal installation → 100% running smoothness test → packaging. Each bearing is spin-tested for noise and vibration before packing.
Quality testing: Bore and flange dimensions verified on air gauges (±2 µm), dynamic load validated on endurance rig (1,000 km travel at rated load), seal effectiveness tested with dust ingress simulation. Exhibitions: Regularly exhibited at PTC Asia, CIMT, and Maker Faire Shenzhen to engage both industrial OEMs and small machine builders.
FAQ
What is the MOQ for LMF square-flange bearings?
MOQ is 100 pieces per size. Mixed sizes accepted in one order with 100-piece minimum per size. Sample quantities of 10–20 pieces available for qualified buyers — contact us with your required sizes.
What are the shipping options and lead time?
FOB Xiamen. In-stock sizes (LMF6–LMF25): 7–10 business days. Larger sizes (LMF30–LMF50): 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.
How are LMF bearings packaged?
Individual anti-corrosion oiled wrapping in plastic bags, then packed in partitioned cartons (50 pieces per carton for LMF6–LMF16, 25 pieces for LMF20–LMF30, 10 pieces for LMF40–LMF50). Wooden pallet packing for bulk export orders.
What payment methods do you accept?
T/T (30% deposit, 70% before shipment). 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.
Are samples available for testing?
Yes. Samples of 10–20 pieces per size available with buyer covering shipping. Sample cost is credited toward bulk orders of 500+ pieces. Provide your required shaft diameter and quantity to arrange.
Do you offer OEM branding and custom packaging?
Yes. Custom logo engraving on flange face available for 200+ piece orders. OEM branded packaging with buyer design available for 500+ piece orders. Custom seal colors and retainer materials can be discussed for high-volume orders — share your requirements.
Request a Quote for LMF Square-Flange Bearings
Send your shaft diameter, flange type, 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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