The 693ZZ bearing is a compact, high-precision miniature ball bearing widely used in fishing reels, small motors, hobby tools, and precision instruments. Its small size, smooth rotation, and ability to operate at high speed make it one of the most versatile miniature bearings in the industry.
This guide from BYWB Bearing explains the 693ZZ specifications, dimensions, sealing options, applications, and material choices — especially for fishing reels and small motors (including rotary tools similar to Saeyang SH37LN). By the end, you’ll know exactly how to choose the right 693 bearing for your needs.
693ZZ Bearing Specifications
The 693ZZ is a miniature deep-groove ball bearing with metal shields on both sides.
Key Specs (Standard)
- Designation: 693ZZ / 693-2Z
Type: Deep groove ball bearing
Inner diameter (d): 3 mm
Outer diameter (D): 8 mm
Width (B): 4 mm
Shield type: ZZ (metal shields, both sides)
Material options: Chrome steel, stainless steel, hybrid ceramic
Lubrication: Pre-greased (varies by application requirement)
Typical speed capability: Tens of thousands of RPM, depending on lubrication and bearing grade
The 693ZZ is engineered to provide low friction, steady rotation, and long lifecycle in miniature machine systems.
What Size Is a 693 Bearing?
All standard 693 bearings use the same dimension:
3 mm × 8 mm × 4 mm
3 mm bore (inner diameter)
8 mm outer diameter
4 mm width
This ultra-compact size is why the 693 bearing is popular in fishing reels, micro motors, hand-held rotary tools, 3D printing mechanisms, RC gearboxes, and compact medical devices.
693 Bearing Sealing Solutions
Miniature bearings like 693 series come with three main closure types:
1. 693ZZ (Metal Shields, Both Sides)
Most common type for high-speed applications
Shields reduce dust entry
Lower friction than rubber seals
Grease retention is good
Ideal for: motors, tools, small spindles, and other clean environments
2. 693-2RS / 693-2RSH (Rubber Seals, Both Sides)
Full-contact seals provide better protection
Better moisture and water resistance
Slightly higher friction than ZZ
Ideal for: fishing reels, outdoor equipment, dusty environments
3. 693 Open Type (No Shields or Seals)
Lowest running friction
For clean and lubrication-controlled environments
Can be re-lubricated
Usually used in instrumentation or enclosed assemblies
Choosing the right seal:
High speed + low torque: 693ZZ
Wet, salty, or dusty environment: 693-2RS (stainless is even better)
Maintenance-friendly, controlled spaces: Open 693
Why the 693ZZ Bearing Is Important
1. High Speed Capability
Thanks to its metal shields and optimized raceway geometry, the 693ZZ can run at extremely high RPM — perfect for small electric motors and precision spindles.
2. Compact Size with Strong Performance
Despite being only 3×8×4 mm, the 693ZZ supports smooth and stable rotation under continuous load.
3. Long Service Life
Precision manufacturing and optimized lubrication extend bearing life even in demanding applications.
4. Versatility Across Industries
From fishing equipment to miniature grinders, the 693ZZ is used in countless devices because it fits tight spaces while delivering professional performance.
What Is the 693ZZ Bearing Used For?
The 693ZZ is used in many compact, high-speed rotating systems. Below are the most important industries and applications.
1. Fishing Reels (Especially Stainless 693 Bearings)
Fishing reels demand low friction, smoothness, and corrosion resistance — all areas where 693 bearings perform exceptionally well.
Why 693 bearings are ideal for reels:
Compact 3×8×4 mm design fits inside small reel housings
Low friction reduces resistance during casting and retrieval
Stainless steel versions resist rust from saltwater
Ceramic hybrids upgrade reels with ultra-low drag and higher sensitivity
2RS seals protect bearings from water and sand
Where 693 bearings are used in fishing reels:
Handle knobs
Spool shafts
Line rollers
Anti-reverse mechanisms
Worm gear shafts
For saltwater reels, stainless 693ZZ or 693-2RS with anti-corrosion grease is strongly recommended.
2. Small Motors & Grinding Machines (e.g., Saeyang SH37LN Type)
Miniature motors inside precision rotary devices, nail drills, and micro-grinders rely heavily on 693ZZ bearings.
Why 693ZZ suits high-speed tools:
High RPM stability
Low vibration and noise
Metal shields keep grease contained inside
Compact size supports small-diameter motor shafts
Equipment similar to Saeyang SH37LN, dental handpieces, micro-engravers, and laboratory rotary tools often contain multiple 683/693 series bearings due to their excellent speed capability.
3. Hobby Tools, Robotics, and Electronics
The 693ZZ is also widely used in:
RC motors and gearboxes
Micro-actuators
Linear sliders
Cooling fans
Electronics with rotating modules
Its low cost and wide availability make it a go-to bearing for engineers, makers, and repair technicians.
Material Options — How to Choose
Chrome Steel (GCr15 / 52100)
Standard and most affordable
High hardness and precision
Suitable for indoor or dry environments
Stainless Steel (AISI 440C)
Superior corrosion resistance
Best for fishing reels, marine environments
Slightly lower load capacity than chrome steel
Hybrid Ceramic (Si3N4 Balls + Steel Races)
Higher speed capability
Lower friction and heat
Longer service life in performance applications
More expensive but ideal for premium fishing reels and precision motors
Quick Selection Guide:
| Condition | Recommended Bearing |
| Saltwater / moisture | Stainless 693ZZ or 693-2RS |
| High speed motor | Chrome 693ZZ or Hybrid Ceramic |
| Harsh dust / dirt | 693-2RS |
| Ultra-low friction | Hybrid Ceramic 693 |
Installation & Maintenance Tips
Press the bearing using proper tools — do not push on the wrong ring
Keep bearings clean during installation
Do not wash out factory grease unless necessary
For fishing reels, use marine-grade lubricants
Replace bearings immediately if you notice noise, vibration, or rust
Do not overload miniature bearings — they’re designed for precision, not heavy loads
Conclusion
The 693ZZ bearing may be tiny, but it is essential in a wide range of high-speed, compact mechanical systems. Its 3×8×4 mm size, combined with sealing options (ZZ / 2RS / open) and material choices (chrome, stainless, hybrid), make it a versatile solution for fishing reels, miniature motors, rotary grinders, hobby components, and more.
Whether you need corrosion resistance for saltwater use, high-speed performance for motor applications, or low-friction hybrid upgrades, choosing the correct 693 bearing ensures longer life, smoother rotation, and more reliable performance.
BYWB Bearing offers 693ZZ, stainless 693, and hybrid ceramic variants with consistent quality and competitive pricing. If you need help selecting the right model, we can recommend the best option based on your application.
Short FAQ for 693 / 693ZZ Bearings (Add Under Article)
1. What is the difference between 693ZZ and 693-2RS?
693ZZ: Metal shields, lower friction, higher speed.
693-2RS: Rubber seals, better waterproofing, slightly higher friction.
2. Can a 693 bearing be re-greased?
Open bearings can be re-greased.
ZZ and 2RS types can be re-greased only if shields/seals are removed, which is not recommended unless you are experienced.
3. Is stainless steel better for fishing reels?
Yes. Stainless steel resists rust and is ideal for saltwater conditions, where chrome steel may corrode.
4. Can 693ZZ bearings handle high RPM?
Yes. 693ZZ bearings are designed for extremely high speeds, making them suitable for dental tools, rotary grinders, and mini-spindles.
5. What is the load capacity of a 693 bearing?
Load capacity is moderate (since it’s a miniature bearing). It is designed for precision rotation, not heavy mechanical load.
6. Is a ceramic 693 bearing worth upgrading to?
For fishing reels and high-speed motors — yes. Ceramic balls offer lower friction and smoother performance.
7. Where is the 693 bearing commonly used?
Fishing reels, RC motors, drones, grinders, small electric motors, actuators, and precision instruments.
8. How do I know if my 693 bearing is failing?
Symptoms include noise, rough rotation, vibration, sticking, or visible rust.
9. Does the shield affect speed?
ZZ shields provide the best balance of protection and speed for miniature bearings.
10. Can the 693 bearing be used in water?
Only if it is stainless steel and preferably sealed (693-2RS). Chrome steel bearings will rust quickly.
