The MRC 211SFF is a single-row deep groove ball bearing designed primarily for radial load while also supporting moderate axial load in both directions.

Its dimensional envelope is:

55 × 100 × 21 mm

which corresponds dimensionally to the modern:

6211

The bearing uses a conventional:

Non-Filling-Slot / Conrad-Type Deep Groove Construction

This differs from MRC maximum-capacity M-series bearings, which use filling slots and a larger ball complement.

The FF protected configuration helps retain grease and reduce the entry of dust and larger contaminants while maintaining relatively low friction compared with contact rubber-sealed bearings.

⚙️ Applications

• Electric motors
• Industrial pumps
• Fans and blowers
• Gearboxes
• Conveyor systems
• Industrial rollers
• Agricultural machinery
• Processing equipment
• Power-transmission systems
• General rotating machinery

🎯 Benefits

✔ Standard 55 × 100 × 21 mm mounting envelope

✔ Single-row deep groove construction

✔ Non-filling-slot design

✔ Good radial-load capability

✔ Moderate axial-load capability in both directions

✔ Double-side protected configuration

✔ Good grease retention

✔ Lower friction than typical contact rubber seals

✔ Modern 6211-series cross-reference options widely available

🧠 Technical Insight

• MRC 211SFF
• MRC 211S
• MRC 200-S Series
• Deep Groove Ball Bearing
• 55 mm Bore
• 100 mm Outside Diameter
• 21 mm Width
• Single Row
• Non-Filling-Slot / Conrad Type
• FF Double-Side Protected
• Modern Dimensional Reference: 6211

✅ Key Features

• MRC (SKF) Bearing
• Model 211SFF
• 200-S Series
• Single-Row Deep Groove Ball Bearing
• 55 mm Bore
• 100 mm OD
• 21 mm Width
• Double-Shielded-Type Configuration

📊 Specifications

Brand: MRC (SKF)

Model / Bearing Number: 211SFF

Base Bearing: MRC 211S

Series: MRC 200-S Series

Modern Dimensional Reference: 6211

Product Type: Deep Groove Ball Bearing

Bearing Type: Single-Row Radial Ball Bearing

Construction: Non-Filling-Slot / Conrad-Type

Bore Diameter (d): 55.00 mm

Outside Diameter (D): 100.00 mm

Width (B): 21.00 mm

Rolling Elements: Ball

Number of Rows: 1

Primary Load: Radial

Axial Load Capability: Moderate axial load in both directions depending on speed, fit, lubrication, and load

Closure: Protected on both sides

FF Suffix: Typically associated with double-side shielding / protection in this MRC family; verify the actual bearing if closure construction is critical

Lubrication: Normally grease-retaining protected-bearing configuration

Internal Clearance: Not defined by the basic 211SFF designation; verify Normal, C3, or another clearance if required

Cage: Verify original MRC production specification

Dynamic Load Rating: Verify original MRC or exact replacement manufacturer data

Static Load Rating: Verify original MRC or exact replacement manufacturer data

Speed Rating: Depends on shield design, grease, internal clearance, fit, temperature, and load

Shaft Fit: Nominal 55 mm shaft

Housing Fit: Nominal 100 mm bearing seat

🔁 Equivalent

Suitable dimensional replacement or cross-reference candidates include:

• MRC 211SFF
• MRC 211S
• SKF 6211-2Z
• FAG 6211-2Z
• NSK 6211ZZ
• NTN 6211ZZ
• KOYO 6211ZZ
• NACHI 6211ZZ
• 55x100x21 Double-Shielded Deep Groove Ball Bearing

MRC 211SFF → Modern 6211 Family

The dimensional relationship is:

MRC 211SFF = 55 × 100 × 21 mm

which corresponds to:

6211

If the original FF execution is confirmed as double metal shielded, the closest modern constructional family is:

6211-2Z / 6211ZZ

depending on manufacturer terminology.

211SFF vs 211S

These bearings may share the same basic dimensions but differ in closure.

MRC 211S

• Standard open deep groove bearing
• No integral shield indicated

MRC 211SFF

• Protected on both sides
• Typically associated with double-side shielding in this MRC family

Therefore, they should not automatically be treated as identical for applications where grease retention, contamination protection, friction, or speed is important.

6211-2Z vs 6211-2RS

Both commonly share:

55 × 100 × 21 mm

but use different closure systems.

6211-2Z / ZZ

• Metal shields on both sides
• Lower friction
• Good grease retention
• Generally better suited to higher speed
• Helps exclude larger dust and debris

6211-2RS / 2RSH / 2RS1

• Rubber seals on both sides
• Better protection against fine dust and moisture
• Higher friction
• Usually lower permissible speed than comparable shielded bearings

Therefore, 6211-2RS should not automatically replace MRC 211SFF solely because the dimensions match.

Important Cross-Reference Consideration

Before replacing MRC 211SFF, verify:

• Bore = 55 mm
• OD = 100 mm
• Width = 21 mm
• Exact shield / seal construction
• Internal clearance
• Cage
• Grease specification
• Precision class
• Operating speed
• Radial load
• Axial load
• Shaft fit
• Housing fit

(Always verify the full marking and actual closure of the original MRC 211SFF before selecting SKF 6211-2Z, FAG 6211-2Z, NTN 6211ZZ, NSK 6211ZZ, or another replacement.)

📦 Availability

✅ In Stock

🚚 Fast Delivery Available

🌎 Worldwide Shipping Available

📦 MOQ: 1 Piece

🏭 Suitable for electric motors, pumps, fans, gearboxes, conveyors, rollers, agricultural machinery, processing equipment, and general industrial machinery requiring a 55x100x21 mm double-side protected deep groove ball bearing.

📲 Contact via LINE ID: dusitrea

📧 Email: sales@seal4go.com

💬 Technical support available before ordering

🔍 Assistance available for cross-reference and equivalent part identification