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MR84ZZ / MR84Z Ultra-Miniature Ball Bearing (4mm x 8mm x 3mm)
- · Inner Diameter: 2.3mm
- · Outer Diameter: 9mm
- · Width: 2.3mm
- · Precision Rating: P0
- · Clearance: C0
- · Sealing Type: ZZ
- · Number of Row: Single Row
- · Material: chrome steel
- · Grease RPM Limit: 2000 RPM
- · Lubrication: Grease
Product Overview
High-Precision MR84ZZ / MR84Z Ultra-Miniature Deep Groove Ball Bearing
The MR84ZZ (MR84Z) Ultra-Miniature Ball Bearing is a metric single-row thin-section deep groove ball bearing engineered for high-precision, low-vibration, and high-speed rotary applications. Featuring an inner bore size of 4.0mm, an outer diameter of 8.0mm, and a width of 3.0mm, the MR84ZZ is an ideal component for micro-mechanical drives, precision sensors, and miniature electronics where space and weight are critical factors.
High-Grade Chrome Steel & Dust Shielded Protection
Manufactured from high-carbon chromium bearing steel (GCr15 / AISI 52100), the inner ring, outer ring, and precision micro balls undergo specialized thermal heat treatment to achieve high surface hardness (HRC 60-65) and structural fatigue strength. Equipped with dual non-contact stamped metal shields (ZZ designation), the bearing retains factory grease and shields internal raceways against ambient dust and foreign particulates.
Ultra-Low Friction & Extreme RPM Capability
Equipped with precision-honed raceway grooves and a balanced ribbon cage, the MR84ZZ bearing achieves exceptional rotational speeds up to 67,000 RPM under oil lubrication. Its sub-micron dimensional tolerances ensure smooth radial guidance and minimal axial play in micro-spindle assemblies.
Custom Manufacturing & Material Options
To support specialized industrial and OEM application environments, custom configurations are available upon request:
- Stainless Steel Options: Stainless steel (SUS440C / SUS304) construction for damp, corrosive, or medical-grade environments.
- Flanged Ring Design: Flanged outer ring model (MF84ZZ) available for simplified housing mounting and axial location.
- Ceramic Hybrid Options: Silicon nitride (Si3N4) ceramic ball options for ultra-high-speed, low-inertia performance.
- Precision Grading: Available in ABEC-1, ABEC-3, ABEC-5, and ABEC-7 tolerance classes.
Technical Specifications
| Inner Diameter | 2.3mm |
| Outer Diameter | 9mm |
| Width | 2.3mm |
| Precision Rating | P0 |
| Clearance | C0 |
| Sealing Type | ZZ |
| Number of Row | Single Row |
| Material | chrome steel |
| Grease RPM Limit | 2000 RPM |
| Lubrication | Grease |
| Size | 2.3*9*3mm |
| Certificate | ISO9001 |