Ningbo Shuanghua Bearings Co., Ltd. (NLHB BEARING) manufactures the 6700, 6800, and 6900 thin section bearing series for applications where weight, envelope size, and friction must be minimized without sacrificing running accuracy. These extra-thin-walled deep groove ball bearings are engineered to meet demanding and application-specific requirements in aerospace, medical systems, robotics, astronomical and optical instruments, semiconductor handling, and precision machine tool spindles. Compared with standard-section bearings of the same bore, NLHB thin section bearings substantially cut space, mass, and system cost while preserving the design flexibility engineers need.
NLHB offers a complete selection of thin section bearings, with options for material, cage/separator type, cross-section, internal clearance or preload, lubricant, corrosion resistance, contact angle, and tolerance grade. Custom designs are available to match your specific requirements.
Key Features
- Space and weight savings: Constant, extra-thin cross-sections reduce housing envelope and rotating mass.
- High running precision: Manufactured to tight tolerances for smooth, low-friction rotation at speed.
- Large bore-to-section ratio: Ideal for shafts that must pass cables, optics, fluids, or air through the bearing bore.
- Deep groove geometry: Supports radial loads, axial loads, and combined loads, plus high limiting speeds in grease or oil lubrication.
- Configurable: Open, shielded, or sealed variants; multiple cage materials; stainless steel available for corrosive environments.
Technical Specifications
The table below lists the NLHB 6700 series thin section bearings. Values for bore (d), outer diameter (D), and width (B) are in millimetres; basic dynamic load rating (Cr) and basic static load rating (Cor) are in newtons (N); limiting speeds are given in r/min for grease and oil lubrication; reference weight is approximate in grams (g).
| Ningbo Shuanghua Bearings Co., Ltd (NLHB BEARING) | ||||||||||
| Part No. | Dimension | Basic Load Rating | Balls | Limiting Speed (r/min) | Weight (approx.) | |||||
| Model | Dimension | Basic Load Rating | Balls | Limiting Speed (r/min) | Weight (approx.) | |||||
| NLHB | Bore d | Outer D | Width B | Dynamic Cr | Static Cor | Qty | Dia. | Grease | Oil | g |
| mm | mm | mm | N | N | PCS | mm | Grease | Oil | ||
| 6700 | 10 | 15 | 4 | 960 | 515 | 13 | φ1.588 | 36000 | 42000 | 1.9 |
| 6701 | 12 | 18 | 4 | 920 | 530 | 13 | φ1.588 | 32000 | 38000 | 3.1 |
| 6702 | 15 | 21 | 4 | 1040 | 730 | 14 | φ1.588 | 28000 | 32000 | 3.6 |
| 6703 | 17 | 23 | 4 | 1000 | 650 | 15 | φ1.588 | 26000 | 30000 | 4 |
| 6704 | 20 | 27 | 4 | 1040 | 730 | 21 | φ1.588 | 23000 | 28000 | 5.9 |
| 6705 | 25 | 32 | 4 | 1100 | 840 | 21 | φ1.588 | 19000 | 23000 | 7 |
| 6706 | 30 | 37 | 4 | 1140 | 950 | 25 | φ1.588 | 16000 | 19000 | 8.3 |
| 6707 | 35 | 44 | 5 | 1810 | 1571 | 25 | φ2.000 | 14000 | 17000 | 15 |
| 6708 | 40 | 50 | 6 | 2519 | 2234 | 25 | φ2.381 | 12000 | 15000 | 23 |
| 6709 | 45 | 55 | 6 | 2580 | 2397 | 27 | φ2.381 | 9000 | 13000 | 25 |
| 6710 | 50 | 62 | 6 | 2670 | 2640 | 30 | φ2.381 | 7000 | 10000 | 34 |
| 6711 | 55 | 68 | 7 | 4890 | 5060 | 32 | φ3.175 | 5000 | 8000 | 55 |
The 6700 series shown above uses the thinnest constant cross-section. NLHB also supplies the 6800 series (medium-thin section) and the 6900 series (extra-light, larger cross-section) for bores from 10 mm upward. Contact our engineering team for the full 6800/6900 dimension tables and for sizes beyond the ranges listed.
How to Choose the Right Thin Section Bearing
- Determine the load type: Predominantly radial loads suit standard deep-groove thin sections; significant axial or moment loads may call for a four-point-contact thin section bearing.
- Fix the envelope first: Because the cross-section stays constant as the bore grows, select the cross-section from your housing and shaft constraints, then choose the bore.
- Check speed and lubrication: Compare your operating speed against the grease and oil limiting speeds in the table; oil lubrication allows higher speeds.
- Specify clearance or preload: Choose internal clearance (C2/C3/C4) for thermal expansion, or preload for maximum stiffness and running accuracy.
- Material and cage: Standard bearing steel suits general use; stainless steel (AISI 440C / X65Cr13) is recommended for corrosive or vacuum environments; polyamide or phenolic cages raise speed capability.
- Tolerance grade: ABEC-5 / ABEC-7 (P5 / P4) tolerances are available for precision spindles and positioning rotary stages.
Typical Applications
- Aerospace actuators, control linkages, and on-board mechanisms
- Medical and surgical equipment, including scanners and imaging gantries
- Industrial and service robotics, collaborative-arm joints, and harmonic reducers
- Astronomical telescopes, optical gimbals, and precision rotary tables
- Semiconductor wafer handling, vacuum stages, and inspection equipment
- Precision machine tool spindles, grinders, and small motor drives
Cross-Reference and Interchangeability
The NLHB thin section numbering (6700 / 6800 / 6900 series) follows the standard ISO deep-groove ball bearing convention and is dimensionally interchangeable with equivalent thin-section deep groove ball bearings from major manufacturers. To cross-reference, match the bore, outer diameter, and width from the table above against the corresponding catalog part. For example, an NLHB 6704 (20 x 27 x 4 mm) shares its envelope with the equivalent 67-series thin section from SKF, NSK, NTN, FAG (Schaeffler), INA, and Timken. Always verify the exact width, clearance, cage, and shield/seal specification before final interchange, and contact NLHB engineering to confirm fitment for safety-critical or high-precision applications.
Installation and Maintenance
- Cleanliness: Thin section bearings have small cross-sections and are sensitive to contamination. Install in a clean environment using lint-free wipes and appropriate solvents.
- Mounting force: Apply mounting force only to the ring being press-fit, never through the rolling elements. Use a calibrated arbor press or induction heater for interference fits.
- Handling distortion: The thin rings can deform under uneven clamping or out-of-round housings. Ensure shaft and housing roundness and tight geometric tolerances.
- Lubrication: Use a high-speed grease for general service or oil mist/jet lubrication near limiting speeds. Avoid over-lubrication, which raises operating temperature.
- Storage: Store bearings in their original packaging in a temperature-stable, low-humidity area; rotate periodically if stored long-term.
Frequently Asked Questions
What is the difference between the 6700, 6800, and 6900 thin section bearing series?
The 6700 series has the thinnest constant cross-section, the 6800 series is medium-thin, and the 6900 series offers a larger cross-section with higher load capacity. All three maintain a constant cross-section as the bore size increases, which is the defining feature of thin section bearings.
Can NLHB thin section bearings be customized?
Yes. NLHB offers options for material (including stainless steel), cage type, internal clearance or preload, lubricant, seals or shields, contact angle, and tolerance grade. Custom designs can be produced to meet specific application requirements.
Do thin section bearings support high speeds?
Yes. With oil lubrication, small-bore 6700 series bearings reach limiting speeds above 40,000 r/min (see the table). Actual attainable speed depends on load, lubrication method, cage material, and mounting precision.
How do I order or request a quotation?
Contact Ningbo Shuanghua Bearings Co., Ltd. (NLHB BEARING) at Tel +86-574-63197518 or Email [email protected]. Share your required part numbers, dimensions, quantity, and any customization needs, and our engineering team will confirm availability and pricing.