Home > miniature-series > 693 Bearing

693 Deep Groove Ball Bearing 3×8×3mm | RHD Bearings

The atom of the bearing world - three millimeter bore with molecular-level precision and nuclear-level reliability.

Meet the 693: With 45kg (0.45kN) of engineering excellence and 3mm 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.

3mm
Bore Diameter
8mm
Outer Diameter
3mm
Width
0.45 kN
Load Rating
45 Kg
Load Capacity
0.0008 Kg
Weight
Technical Specifications Applications 📞 Call +91-9702081858
693 Bearing 3×8×3mm - RHD Bearings

693 BEARING SPECIFICATIONS

Precision-engineered for reliability and performance

🔍 Common Search Terms

693 bearing dimensions 3mm bore ball bearing ultra-micro bearing nano-scale bearing ultra-precision bearing micro-electronic bearing

📏Dimensions

d - ID (Bore Diameter)
3mm
D - OD (Outer Diameter)
8mm
B - Width
3mm
693 Bearing: 3 × 8 × 3mm

Bearing Cross-Sectional View

693 Deep Groove Ball Bearing Technical Drawing

⚡Load Ratings

Dynamic Load (Cr) 0.45kN
Static Load (Cor) 0.15kN
Load Capacity (kN) 0.45kN
Load Capacity (kg) 45kg

💡What This Means

Dynamic Load (0.45kN): Maximum force while rotating. Exceeding this causes rapid wear and failure within hours.
Static Load (0.15kN): 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 44000 RPM
Oil Lubrication 52000 RPM
RHD Z2V2 Bearings 1400 RPM
RHD Z3V3 Bearings 2880 RPM
RHD Z4V4 Bearings 6000+ RPM

💡What This Means

Grease Limit (44000 RPM): Heat generation increases exponentially above this. Grease breaks down, causing seizure.
Oil Advantage (52000 RPM): Better heat dissipation allows higher speed. Required for high-speed spindles.
Safe Operating Speed: Use 90% of limit (39600 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 693 application worldwide

📊Vibration Classes

V2 Grade
Low: 48 μm/s
Med: 26 μm/s
High: 22 μm/s
V3 Grade
Low: 31 μm/s
Med: 16 μm/s
High: 15 μm/s
V4 Grade
Low: 28 μm/s
Med: 10 μm/s
High: 10 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 < 32 dB
Z3 Grade < 28 dB
Z4 Grade (Quiet) < 24 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

693-ZZ

Most Popular

Double metal shields

Speed Factor: 0.9 (39600 RPM)
Protection: Dust protection
Lubrication: Sealed for life

When to Use 693-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

693-2RS

Protected

Double rubber seals

Speed Factor: 0.7 (30800 RPM)
Protection: Moisture and dust
Lubrication: Sealed for life

When to Use 693-2RS

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

693

High Speed

Open bearing, no seals

Speed Factor: 1.0 (44000 RPM)
Protection: None
Lubrication: External required

693-Z

Balanced

Single metal shield

Speed Factor: 0.95 (41800 RPM)
Protection: Light dust protection
Lubrication: Pre-greased

693-RS

Protected

Single rubber seal

Speed Factor: 0.8 (35200 RPM)
Protection: Moisture and dust
Lubrication: Pre-greased, sealed

APPLICATIONS

Precision performance across industries

Ultra-Micro Systems

  • micro-electronic components
  • ultra-precision instruments
  • nano-scale mechanisms
  • microscopic assemblies
  • atomic force microscopy
  • quantum computing devices
  • molecular machines
  • ultra-fine positioning

Key Requirements: 3mm shaft with 0.45kN dynamic load capacity, 44,000 RPM grease lubrication, ultra-micro 8×3mm profile for nano-scale applications

Ultra-High Precision

  • optical alignment systems
  • ultra-precision measurement
  • calibration standards
  • reference instruments
  • metrology equipment
  • standards laboratories
  • precision optics
  • ultra-fine adjustment

Key Requirements: 3mm precision shaft with 0.15kN static load rating, ultra-high speed capability, molecular-level precision for ultra-precision applications

Micro-Scale Automation

  • micro-robotics
  • nano-manipulation
  • ultra-precise actuators
  • micro-positioning systems
  • nano-scale automation
  • ultra-fine control
  • micro-assembly
  • nano-fabrication

Key Requirements: 3mm shaft with 46kg load capacity, ultra-lightweight 0.8g design, reliable 44,000 RPM operation for micro-scale systems

Compatible Models & Shaft Requirements

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

🔄Related Models

623 (3×10×4mm) 683 (3×7×2mm) 693 (3×8×3mm) 694 (4×11×4mm)

🔧Shaft Requirements

Nominal Diameter 3.000mm
Tolerance Grade h6 (2.992-3.000mm)
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 ultra-micro 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

Handles 0.20kN more load than typical smaller bearings while maintaining ultra-micro design. Superior Gcr15 steel vs. standard steel in competing products.

💰Value Engineering

Best value in ultra-micro bearing category for 0.45kN performance. Quality bearings last 3-10x longer than cheap alternatives, reducing total cost of ownership.

FREQUENTLY ASKED QUESTIONS

Expert guidance for 693 bearing applications

Bearing Selection & Replacement ▼

When should I choose 693 bearing over larger alternatives?

Choose 693 when you need ultra-micro 3×8×3mm profile with 45.9kg (0.45kN) dynamic load capacity for ultra-micro systems, nano-scale applications, or ultra-precision instruments where every micron matters.
Why This Matters
Selecting the right bearing size prevents system redesign, reduces costs, and ensures optimal performance in nano-scale applications.
How To Handle It
Measure your shaft diameter (must be exactly 3mm), verify load requirements (≤45.9kg (0.45kN) dynamic), and confirm space constraints allow 8×3mm envelope.
693 is ideal for ultra-micro systems, nano-scale mechanisms, and ultra-precision instruments where molecular-level precision is required.

Can 693 bearing replace other 3mm bore bearings?

Yes, 693 can replace other 3mm bore bearings if they have compatible outer diameter (≤8mm) and width (≤3mm) requirements, and load capacity needs (≤45.9kg (0.45kN) dynamic).
Why This Matters
Proper replacement ensures system compatibility, prevents premature failures, and maintains performance specifications.
How To Handle It
Verify dimensional compatibility (d×D×B), check load ratings, confirm clearance requirements, and ensure speed limitations are met.
Always check both dimensional and performance compatibility before replacement to avoid system issues.

What applications are 693 bearings NOT suitable for?

693 bearings are NOT suitable for applications requiring dynamic loads >45.9kg (0.45kN), speeds >44,000 RPM, operating temperatures >120°C, or environments with heavy contamination.
Why This Matters
Using bearings beyond their specifications leads to premature failure, increased maintenance costs, and potential system damage.
How To Handle It
For higher loads, consider 694 or 695 bearings. For higher speeds, use oil lubrication. For harsh environments, consider sealed or stainless steel alternatives.
Always verify application requirements against bearing specifications to ensure long service life.
Installation & Maintenance ▼

What tools are needed for proper 693 bearing installation?

For 693 bearing installation, you need ultra-precision tools: 3mm bore gauge, micrometer for shaft measurement, bearing heater (80-100°C), clean gloves, and appropriate mounting tools for the 8mm outer diameter.
Why This Matters
Proper tools ensure accurate installation, prevent bearing damage, and maximize service life while maintaining ultra-precision requirements.
How To Handle It
Clean all components thoroughly, verify shaft dimensions (2.992-3.000mm), heat bearing to 80-100°C, and use proper mounting techniques to avoid damage.
Never force-fit 693 bearings - the 3mm bore requires ultra-precise shaft tolerances for optimal performance.

How often should 693 bearings be lubricated?

Open 693 bearings require lubrication every 2-4 months depending on operating conditions. Shielded/sealed versions are lubricated for life but may need replacement after 1-2 years.
Why This Matters
Proper lubrication prevents wear, reduces friction, and extends bearing life. Over-lubrication can cause overheating, while under-lubrication leads to premature failure.
How To Handle It
Monitor operating temperature and noise levels. For open bearings, use high-quality grease compatible with operating conditions. Replace sealed bearings when performance degrades.
693 bearings in ultra-high-speed applications (>30,000 RPM) may require more frequent lubrication due to increased operating temperatures.

What maintenance schedule is recommended for 693 bearings?

For 693 bearings, inspect weekly for noise, vibration, and temperature changes. Clean and relubricate open bearings every 2-4 months. Replace sealed bearings every 1-2 years or when performance degrades.
Why This Matters
Regular maintenance prevents unexpected failures, maintains ultra-precision performance, and extends bearing service life in critical nano-scale applications.
How To Handle It
Establish maintenance logs, monitor operating parameters, and replace bearings proactively rather than reactively. Use vibration analysis for early failure detection.
693 bearings in ultra-precision instruments require more frequent inspection due to critical nano-scale performance requirements.
Troubleshooting & Problem Solving ▼

Why is my 693 bearing making unusual noise?

Unusual noise in 693 bearings typically indicates contamination, improper lubrication, misalignment, or wear. The 3mm bore is extremely sensitive to shaft imperfections and contamination due to its ultra-micro size.
Why This Matters
Early noise detection prevents bearing failure, maintains ultra-precision, and reduces maintenance costs in nano-scale applications.
How To Handle It
Inspect for contamination, check lubrication levels, verify shaft alignment and surface finish, and replace bearing if noise persists or worsens.
693 bearings amplify noise due to their ultra-micro size - what sounds minor in larger bearings can indicate serious issues in nano-scale bearings.

What causes 693 bearing overheating?

693 bearing overheating is caused by over-lubrication, excessive load (>45.9kg (0.45kN)), high speeds (>44,000 RPM), misalignment, or contamination. The ultra-micro size makes 693 bearings extremely sensitive to these conditions.
Why This Matters
Overheating accelerates wear, reduces ultra-precision, and can cause catastrophic failure in nano-scale bearing applications.
How To Handle It
Check lubrication quantity and type, verify load and speed limits, inspect alignment, clean contamination, and ensure proper ventilation around the bearing.
693 bearings have extremely limited heat dissipation due to ultra-micro size - monitor temperature closely in high-speed applications.

How do I diagnose 693 bearing vibration issues?

Diagnose 693 bearing vibration by checking shaft runout (≤0.013mm), verifying balance, inspecting for contamination, and measuring vibration levels against V2/V3/V4 standards for 3mm bore bearings.
Why This Matters
Excessive vibration reduces ultra-precision, increases wear, and can damage connected equipment in nano-scale applications.
How To Handle It
Use vibration analysis tools, check shaft specifications, verify bearing installation, and replace bearing if vibration exceeds acceptable limits.
693 bearings require ultra-precision in shaft preparation due to their ultra-micro size and extreme sensitivity to imperfections.
Cost & Performance Optimization ▼

How can I optimize 693 bearing performance for cost efficiency?

Optimize 693 bearing performance by selecting appropriate clearance (C0 for most applications), using proper lubrication, maintaining ultra-clean environment, and implementing preventive maintenance to extend service life beyond 50,000 hours.
Why This Matters
Performance optimization reduces total cost of ownership, minimizes downtime, and ensures consistent ultra-precision in nano-scale applications.
How To Handle It
Choose clearance based on application requirements, establish maintenance schedules, monitor operating conditions, and replace bearings proactively rather than reactively.
693 bearings offer excellent value when properly maintained - their ultra-micro size means replacement costs are minimal compared to system downtime.

What factors affect 693 bearing service life?

693 bearing service life is affected by load conditions (≤45.9kg (0.45kN)), operating speed (≤44,000 RPM), environmental cleanliness, lubrication quality, installation precision, and maintenance practices.
Why This Matters
Understanding service life factors helps optimize maintenance schedules, reduce costs, and ensure reliable operation in critical nano-scale applications.
How To Handle It
Monitor operating parameters, maintain ultra-clean environment, use quality lubricants, implement preventive maintenance, and replace bearings based on performance degradation.
693 bearings can achieve 50,000+ hours service life when operated within specifications and properly maintained.

How do 693 bearings compare to alternatives in terms of total cost?

693 bearings offer excellent total cost value for ultra-micro applications due to their ultra-micro size, reliable performance, and low replacement costs. Quality 693 bearings last 3-10x longer than cheap alternatives, reducing total cost of ownership.
Why This Matters
Total cost analysis helps make informed purchasing decisions, considering initial cost, maintenance, replacement, and downtime costs over the bearing's service life.
How To Handle It
Compare initial costs, expected service life, maintenance requirements, and replacement costs. Consider system downtime costs when evaluating alternatives.
693 bearings provide optimal cost-performance ratio for ultra-micro applications when quality and proper maintenance are prioritized.
🔥 FAST DELIVERY

Need 693 Bearings Today?

Get instant pricing and availability for premium 693 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