618/670 MB Deep groove ball bearings
618/670 MB Deep groove ball bearings 670X820X69mm - Image 2
618/670 MB Deep groove ball bearings 670X820X69mm - Image 3
618/670 MB Deep groove ball bearings

618/670 MB Deep groove ball bearings 670X820X69mm

ZQM 618/670MB Thin-Section Deep Groove Ball Bearing

Extra-Large Series (670x820x69 mm) | Machined Brass Cage

Maximize performance in limited space. The ZQM 618/670MB is a premium single-row thin-section bearing designed for heavy steel mills and large motor assemblies. Unlike standard stamped steel cages, our “MB” design features a solid machined brass cage, providing superior stability and vibration resistance under medium-to-high speeds.

  • ✔
    Precision Dimensions: 670mm ID x 820mm OD x 69mm Width.
  • ✔
    Heavy-Duty Cage (MB): Solid Brass Cage for enhanced durability in harsh mining & steel environments.
  • ✔
    Lightweight Efficiency: Weighs only 81.9 kg, optimizing torque and reducing structural load.
  • ✔
    Application Ready: Engineered for steel milling machines, industrial turntables, and large electrical motors.

⚙️ Fit & Tolerance Check: Replacing an old bearing?
Contact ZQM Engineering to confirm radial clearance (C3/C4) and fit requirements before ordering.

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ZQM 618/670 MB Deep Groove Ball Bearing (670x820x69 mm)

When precision meets scale. The 618/670 MB Deep Groove Ball Bearing is a masterpiece of thin-section engineering. Designed for applications where weight reduction and space efficiency are critical, this Single Row Deep Groove Ball Bearing delivers exceptional stability under radial loads.

Key Dimensions: Bore 670mm | OD 820mm | Width 69mm
Weight: 81.9 kg (Lightweight Design)
Cage Type: MB (Machined Brass) – Superior durability vs. steel.

Why Choose ZQM 618/670 MB?

1. Premium GCr15 High-Carbon Chrome Steel

We don’t cut corners on materials. The rings and rolling elements are forged from high-grade GCr15 (AISI 52100) steel. This ensures high rolling contact fatigue strength and exceptional wear resistance, crucial for the massive 820mm outer ring to maintain dimensional stability.

2. Machined Brass Cage (MB) – The “Gold” Standard

Unlike stamped steel cages, the “MB” suffix indicates a solid Machined Brass Cage. For a bearing of this size (Extra-Large), a brass cage provides:

  • Vibration Damping: Absorb shock loads in heavy steel mill equipment.
  • Low Friction: Reduces operating temperature and extends grease life.
  • High-Speed Capability: Can withstand higher rotational forces than steel cages.

3. Precision & Tolerance (P6/P5 Available)

Standard doesn’t mean average. While standard manufacturing follows Normal tolerances, ZQM offers the 618/670 MB with P6 dimensional accuracy options.

Need specific clearance? We supply C3 (larger clearance) for high-temperature environments or C2 for rigid setups.

Technical Specifications Data

Verified parameters for 618/670 MB Series.

Part Number 618/670 MB (Interchangeable with SKF/FAG)
Inner Diameter (d) 670 mm
Outer Diameter (D) 820 mm
Width (B) 69 mm
Basic Dynamic Load (Cr) 420 kN
Basic Static Load (Cor) 780 kN
Weight 82.8 kg
Cage Material Machined Brass (MB/MA)

Typical Applications

The 618/670 MB is engineered for industries demanding reliability:

  • Heavy Industry: Steel rolling mills and mining conveyors.
  • Power Generation: Large electrical motors and wind turbines.
  • Precision Machinery: Industrial turntables and radar systems.

Need a Custom Fit or Bulk Pricing?
Don’t guess on tolerances. Contact ZQM Engineering Team today. We provide mill certificates, global shipping, and technical support for large-bore bearings.

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