Home > miniature-series > 628 Bearing

628 Bearing 8×24×8mm Deep Groove Ball Bearing | RHD

The 8mm powerhouse - where precision meets performance in a compact, reliable package.

Meet the 628: With 341kg (3.35kN) of engineering excellence and 8mm precision, this bearing delivers the perfect blend of personality and performance for your critical applications. The most widely used bearing in electronics, small motors, and precision instruments.

8mm
Bore Diameter
24mm
Outer Diameter
8mm
Width
3.35 kN
Load Rating
341 Kg
Load Capacity
0.016 Kg
Weight
Technical Specifications Applications 📞 Call +91-9702081858
628 Bearing 8×24×8mm - RHD Bearings

628 BEARING SPECIFICATIONS

Precision-engineered for reliability and performance

🔍 Common Search Terms

628 bearing dimensions 8mm bore bearing load capacity miniature bearing for automation precision machinery bearing electric vehicle bearing 8mm shaft 628 bearing specifications

📏Dimensions

d - ID (Bore Diameter)
8mm
D - OD (Outer Diameter)
24mm
B - Width
8mm
628 Bearing: 8 × 24 × 8mm

Bearing Cross-Sectional View

628 Deep Groove Ball Bearing Technical Drawing

⚡Load Ratings

Dynamic Load (Cr) 3.35kN
Static Load (Cor) 1.4kN
Load Capacity (kN) 3.35kN
Load Capacity (kg) 341kg

💡What This Means

Dynamic Load (3.35kN): Maximum force while rotating. Exceeding this causes rapid wear and failure within hours.
Static Load (1.4kN): Maximum force when stationary. Use 80% for safety.
Calculate Your Load: Measure shaft forces, belt tensions, or gear loads. Include shock/vibration factors.
Failure Warning: Overloading causes bearing raceways to crack and balls to flatten permanently.

🔄Speed Limits

Grease Lubrication 24000 RPM
Oil Lubrication 32000 RPM
RHD Z2V2 Bearings 1400 RPM
RHD Z3V3 Bearings 2880 RPM
RHD Z4V4 Bearings 6000+ RPM

💡What This Means

Grease Limit (24000 RPM): Heat generation increases exponentially above this. Grease breaks down, causing seizure.
Oil Advantage (32000 RPM): Better heat dissipation allows higher speed. Required for high-speed spindles.
Safe Operating Speed: Use 90% of limit (21600 RPM) for maximum L10 life of 10,000+ hours.
Failure Mode: Exceeding speed causes cage failure, ball skidding, and catastrophic overheating within minutes.

🔧Material & Quality

Steel Grade SAE52100
Ball Grade G10
Carbon Content 0.95-1.05%
Chromium Content 1.40-1.65%
ISO Standard 15:2011 Compliant

💡What This Means

SAE52100 Chrome Steel: Premium bearing steel - harder than tool steel
G10 Balls: Ultra-precision balls with ±0.25µm tolerance
High Carbon: Superior hardness and wear resistance
Chromium: Adds corrosion resistance and toughness
ISO Standard: Fits any 628 application worldwide

📊Vibration Classes

V2 Grade
Low: 72 μm/s
Med: 48 μm/s
High: 40 μm/s
V3 Grade
Low: 44 μm/s
Med: 28 μm/s
High: 24 μm/s
V4 Grade
Low: 38 μm/s
Med: 12 μm/s
High: 12 μm/s

💡What This Means

V2 Grade: Standard grade - good for general applications
V3 Grade: Low vibration - like a smooth car engine
V4 Grade: Ultra-smooth - for precision instruments
Frequency Bands: Measured across different rotation speeds

🔇Noise Levels

Z2 Grade < 35 dB
Z3 Grade < 31 dB
Z4 Grade (Quiet) < 27 dB
Application Precision Equipment

💡What This Means

Z2 Grade: Quiet as a library - good for most applications
Z3 Grade: Very quiet - like a whisper (40 dB = normal whisper)
Z4 Grade: Ultra-quiet - perfect for bedroom fans, medical equipment
Application: Ideal for sensitive environments

⚙️Internal Clearance

C2 (Tight) 0-7 μm
C0 (Normal) 2-13 μm
C3 (Loose) 8-23 μm
C4 (High Temp) 14-29 μm
C5 (Extra High Temp) 20-37 μm

💡What This Means

C2 (Tight): Precision applications - less play, more accurate
C0 (Normal): Standard choice - works for most applications
C3 (Loose): Better for hot environments - allows thermal expansion
C4 (Exta Loose): Hot or tight-fit setups — extra room for thermal expansion.
C5 (Max Loose): Extreme heat/tight fits or near-limit speeds — maximum expansion allowance

SEAL OPTIONS

Choose the right protection for your application

628-ZZ

Most Popular

Double metal shields

Speed Factor: 0.9 (21600 RPM)
Protection: Dust protection
Lubrication: Sealed for life

When to Use 628-ZZ

Best For: Electronics, small motors, skateboards, general machinery
Conditions: Dry environments, moderate dust, precision applications
Achieves: Excellent balance of speed and protection for most applications
Avoid When: Heavy water exposure, chemical environments, food processing

628-2RS

Protected

Double rubber seals

Speed Factor: 0.7 (16800 RPM)
Protection: Moisture and dust
Lubrication: Sealed for life

When to Use 628-2RS

Best For: Outdoor applications, appliances, automotive systems, dirty environments
Conditions: Moisture, dust, contamination, washdown areas, food processing
Achieves: Maximum protection and zero maintenance requirements
Trade-off: Lower speed limit but superior environmental protection

628

High Speed

Open bearing, no seals

Speed Factor: 1.0 (24000 RPM)
Protection: None
Lubrication: External required

628-Z

Balanced

Single metal shield

Speed Factor: 0.95 (22800 RPM)
Protection: Light dust protection
Lubrication: Pre-greased

628-RS

Protected

Single rubber seal

Speed Factor: 0.8 (19200 RPM)
Protection: Moisture and dust
Lubrication: Pre-greased, sealed

APPLICATIONS

Precision performance across industries

Industrial Automation

  • robotic arms
  • conveyor systems
  • pick-and-place machines
  • assembly robots
  • material handling
  • packaging equipment
  • quality control
  • production monitoring

Key Requirements: 8mm shaft with 3.35kN dynamic load capacity, 24,000 RPM grease lubrication, robust 24×8mm profile for automation applications

Precision Machinery

  • machine tools
  • grinding machines
  • milling equipment
  • lathe spindles
  • drill presses
  • cutting tools
  • boring machines
  • reaming tools

Key Requirements: Precision 8mm bore with 0.3mm chamfer radius, 1.40kN static load rating for stable operation, 143kg load capacity for machining accuracy

Electric Vehicles

  • motor shafts
  • drive systems
  • battery cooling
  • climate control
  • steering systems
  • brake mechanisms
  • charging systems
  • battery management

Key Requirements: 8mm bore fits EV shafts, 8mm width for compact mounting, 341kg weight for efficiency, 32,000 RPM oil lubrication capability

Compatible Models & Shaft Requirements

Find bearings with the same bore size and ensure proper shaft preparation

🔄Related Models

688 (8×16×5mm) 698 (8×19×6mm) 608 (8×22×7mm)

🔧Shaft Requirements

Nominal Diameter 8.000mm
Tolerance Grade h6 (7.991-8.000mm)
Surface Finish Ra 0.8μm max
Runout Tolerance 0.013mm max

🎯Application-Specific Options

High Temperature: C3 clearance recommended
High Speed: RHD V3 & V4 bearings recommended
Corrosive Environment: SS (Stainless Steel) bearings recommended

Professional Expertise & Standards

Technical insights from 20+ years of bearing engineering and manufacturing excellence

📋ISO Compliance

ISO 15:2011 compliant dimensions ensure interchangeability with global bearing standards and seamless replacement in existing equipment.

🔬Material Science

Gcr15 chrome steel composition optimized for small bearing applications, providing superior hardness, wear resistance, and fatigue life.

⚙️Precision Engineering

C0 clearance standard for most applications, C3 available for high-temperature use. h6 shaft tolerance recommended for optimal performance.

🔧Professional Installation

Professional installation required for maximum 50,000-hour service life. Proper tools and techniques prevent 80% of premature failures.

📊Performance Comparison

Shares the 8mm bore (ID) with 688, 698, 608, so it can be considered where the shaft is fixed at 8mm. The 628 is rated 3.35kN dynamic / 1.40kN static at 24mm OD — the highest-capacity 8mm-bore option, above the 608 (3.32kN).

💰Value Engineering

Best value in miniature bearing category for 3.35kN performance. Quality bearings last 3-10x longer than cheap alternatives, reducing total cost of ownership.

FREQUENTLY ASKED QUESTIONS

Expert guidance for 628 bearing applications

Bearing Selection & Replacement ▼

What shaft tolerance is recommended for 628 bearing installation?

h6 tolerance grade (7.991-8.009mm) provides optimal fit and performance for 628 bearings.
Why This Matters
Proper shaft tolerance ensures correct interference fit, preventing slippage while allowing thermal expansion.
How To Handle It
Measure shaft diameter with precision micrometers, ensuring it falls within h6 tolerance range before installation.
Use h6 tolerance for standard applications, h5 for high-precision requirements, and h7 for loose fits.

Can I replace a 628 bearing with a different size bearing?

No, 628 bearings have unique 8×24×8mm dimensions and cannot be replaced with other sizes without mechanical modifications.
Why This Matters
Bearing dimensions are critical for proper fit, load distribution, and system performance.
How To Handle It
Always use exact 628 replacement or consult engineering specifications for alternative solutions.
Keep spare 628 bearings in stock to avoid production delays and ensure consistent quality.

What load capacity does the 628 bearing provide?

628 bearing offers 402.9kg (3.95kN) dynamic load capacity and 1.50kN static load capacity, suitable for industrial automation applications.
Why This Matters
Load capacity determines bearing suitability for specific applications and operating conditions.
How To Handle It
Calculate actual application loads and ensure they remain within 402.9kg (3.95kN) dynamic limit with appropriate safety factors.
Use 628 bearings for applications requiring up to 403kg load capacity with standard safety margins.
Installation & Maintenance ▼

What lubrication is required for 628 bearings?

628 bearings require grease lubrication for standard applications, with 24,000 RPM capability under proper lubrication conditions.
Why This Matters
Proper lubrication reduces friction, prevents wear, and extends bearing service life significantly.
How To Handle It
Apply high-quality bearing grease during installation and maintain regular lubrication intervals based on operating conditions.
Use lithium-based grease for general applications and synthetic grease for high-temperature or high-speed operations.

How do I properly install a 628 bearing?

Install 628 bearings using proper bearing installation tools, ensuring even pressure distribution and avoiding damage to bearing surfaces.
Why This Matters
Proper installation prevents premature failure, ensures optimal performance, and maintains dimensional accuracy.
How To Handle It
Use bearing heaters for interference fits, apply force evenly, and verify proper seating after installation.
Professional installation tools prevent 80% of premature bearing failures and ensure maximum service life.

What maintenance schedule is recommended for 628 bearings?

628 bearings require regular inspection every 3-6 months, with lubrication replenishment based on operating hours and conditions.
Why This Matters
Regular maintenance prevents unexpected failures, maintains performance, and extends bearing lifespan.
How To Handle It
Establish maintenance schedules based on operating conditions, document all maintenance activities, and monitor bearing condition regularly.
Implement predictive maintenance using vibration analysis to detect issues before they cause failures.
Troubleshooting & Problem Solving ▼

What causes premature failure in 628 bearings?

Common causes include improper installation, inadequate lubrication, contamination, excessive loads, and misalignment.
Why This Matters
Understanding failure causes helps prevent future issues and improves system reliability.
How To Handle It
Implement proper installation procedures, maintain clean environments, ensure adequate lubrication, and monitor operating conditions.
80% of premature failures are preventable through proper installation and maintenance practices.

How do I identify bearing wear in 628 bearings?

Signs of wear include increased noise, vibration, temperature rise, and reduced performance in 628 bearings.
Why This Matters
Early detection of wear prevents catastrophic failures and allows for planned replacement.
How To Handle It
Monitor bearing condition regularly, use vibration analysis equipment, and establish baseline performance measurements.
Implement condition monitoring systems to detect wear patterns before they affect system performance.

What should I do if a 628 bearing fails unexpectedly?

Immediately stop operation, inspect for damage, identify root cause, and replace with properly installed new bearing.
Why This Matters
Quick response prevents secondary damage and minimizes production downtime.
How To Handle It
Document failure details, analyze root causes, implement corrective actions, and maintain spare bearings for critical applications.
Keep detailed failure records to identify patterns and prevent similar issues in the future.
Cost & Performance Optimization ▼

How does 628 bearing cost compare to alternatives?

628 bearings offer excellent value with 402.9kg (3.95kN) load capacity at competitive pricing, providing 3-10x longer lifespan than budget alternatives.
Why This Matters
Total cost of ownership includes initial cost, maintenance, replacement frequency, and downtime costs.
How To Handle It
Calculate total cost of ownership, consider quality vs. price trade-offs, and invest in proper installation and maintenance.
High-quality bearings like 628 typically cost 20-30% more but last 3-10x longer than budget alternatives.

What performance benefits does 628 bearing provide?

628 bearings deliver high load capacity, excellent speed capability, precision dimensions, and reliable performance in automation applications.
Why This Matters
Performance directly impacts system efficiency, reliability, and overall productivity.
How To Handle It
Select 628 bearings for applications requiring 8mm bore, 402.9kg (3.95kN) load capacity, and 24,000 RPM capability.
628 bearings excel in applications requiring automation performance with substantial load handling.

How can I optimize 628 bearing performance?

Optimize performance through proper installation, adequate lubrication, contamination control, and regular maintenance practices.
Why This Matters
Optimized performance extends bearing life, reduces maintenance costs, and improves system reliability.
How To Handle It
Follow manufacturer recommendations, implement preventive maintenance, monitor operating conditions, and use quality lubricants.
Proper optimization can extend 628 bearing service life from 20,000 to 50,000+ hours in typical applications.
🔥 FAST DELIVERY

Need 628 Bearings Today?

Get instant pricing and availability for premium 628 bearings. Same-day dispatch available for orders before 2 PM.

⚡

Instant Quote

Real-time pricing & availability

🚀

Same Day Dispatch

Orders before 2 PM ship today

🏆

Premium Quality

ISO certified, 20+ years expertise

📞 Call Now +91-9702081858 📧 Email Quote Instant Response
RHD Bearings Your Trusted Bearing Partner
📍 203 Vihar Estate, Sakinaka, Andheri East, Mumbai 400072
OEM Sales: oemsales@rhdenterprise.in
Bulk Orders: Significant discounts available
BEARINGS