The SKF 6304ZY is a single-row deep groove ball bearing intended for general industrial rotating equipment.

Nominal dimensions:

Bore Diameter: 20 mm
Outside Diameter: 52 mm
Width: 15 mm

Approximate inch dimensions:

0.787 × 2.047 × 0.591 in

The actual bearing observed has a metal shield on one side only, which strongly supports interpreting the Z as the shield designation.

The opposite side exposes the cage and rolling elements, where the cage appears yellow-gold in color.

This appearance is consistent with a brass cage, a cage material historically used in many industrial bearing designs because of characteristics such as:

• Good strength
• Good dimensional stability
• Good wear resistance
• Suitability for demanding operating conditions
• Good behavior under vibration and fluctuating loads

However, cage color alone is not sufficient to distinguish whether the cage is:

• Pressed brass
• Machined brass
• Brass-alloy cage of another execution

Therefore, the safest technical description is:

Brass Cage – exact pressed/machined execution to be verified

⚙️ Applications

• Electric motors
• Pumps
• Fans and blowers
• Industrial gearboxes
• Machine tools
• Conveyor systems
• Mechanical transmissions
• Agricultural machinery
• Legacy industrial equipment
• Vintage machinery restoration

🎯 Benefits

✔ Standard 20 × 52 × 15 mm dimensions

✔ Single-row deep groove construction

✔ One-side metal shield

✔ Brass cage construction consistent with industrial-duty bearing design

✔ Good radial-load capability

✔ Moderate axial-load capability in both directions

✔ Low-friction operation

✔ Suitable for legacy equipment restoration

✔ Cross-reference support available

🧠 Technical Insight

• SKF 6304 Deep Groove Bearing
• Single-Row Construction
• 20 mm Bore
• 52 mm Outside Diameter
• 15 mm Width
• Z = Single Metal Shield
• Brass-Colored Cage
• Exact Y-Suffix Historical Meaning Should Be Verified

✅ Key Features

• SKF Industrial Bearing
• Model 6304ZY
• Single Metal Shield
• Brass Cage
• Deep Groove Raceway
• Single-Row Design
• Metric 6304 Dimensions
• Legacy SKF Execution

📊 Specifications

Brand: SKF

Model / Bearing Number: 6304ZY

Basic Bearing Number: 6304

Bearing Series: 63-Series

Bearing Type: Single-Row Deep Groove Ball Bearing

Bore Diameter (d): 20 mm

Outside Diameter (D): 52 mm

Width (B): 15 mm

Approx. Inch Equivalent: 0.787 × 2.047 × 0.591 in

Rolling Elements: Ball

Number of Rows: 1

Raceway Type: Deep Groove

Closure Configuration: One metal shield

Suffix Z: Single metal shield on one side

Cage Material: Brass-colored cage; consistent with brass construction

Cage Type: Exact pressed or machined brass execution should be verified from original SKF documentation

Suffix Y: May be associated with a historical cage or internal execution, but should not be decoded conclusively without period-specific SKF documentation

Load Capability: Primarily radial load with moderate axial-load capability in both directions

Lubrication: One-side shielded construction; actual lubrication arrangement depends on application

Internal Clearance: Verify original bearing marking/specification

Speed Rating: Depends on cage, lubrication, internal clearance, load, fit, and operating temperature

Shaft Fit: Nominal 20 mm

Housing Fit: Nominal 52 mm

Installation Consideration: Preserve the original single-shield arrangement and confirm cage, clearance, lubrication, and operating environment before replacement

🔁 Equivalent

Suitable replacement or cross-reference candidate for compatible:

• SKF 6304ZY
• SKF 6304-Z
• 6304 Single-Shield Bearing
• 20x52x15 mm Deep Groove Ball Bearing
• 20 mm Bore Industrial Bearing
• 52 mm OD Bearing
• Single-Shield 6304 Bearing
• Brass-Cage 6304 Bearing
• Legacy SKF 6304 Bearing
• Industrial 6304 Replacement Bearing

A modern SKF 6304-Z may be dimensionally close because it also uses a single metal shield, but it should not automatically be treated as an exact historical equivalent if the original 6304ZY uses a different cage, internal clearance, lubrication, or internal execution.

(Always verify cage type, clearance, lubrication, and operating requirements before replacing the original SKF 6304ZY.)

📦 Availability

✅ In Stock

🚚 Fast Delivery Available

🌎 Worldwide Shipping Available

📦 MOQ: 1 Piece

🏭 Suitable for motors, pumps, fans, gearboxes, conveyors, machine tools, and legacy industrial machinery using a single-shield 20 × 52 × 15 mm bearing.

📲 Contact via LINE ID: dusitrea

📧 Email: sales@seal4go.com

💬 Technical support available before ordering

🔍 Assistance available for cross-reference and equivalent part identification