SAF pillow block bearings are critical components in heavy-duty industrial machinery, known for their strength, reliability, and ease of maintenance. These rugged units are designed for heavy-duty applications in industries like mining, cement, and pulp processing, offering durability and simplified maintenance. 

Whether replacing a worn-out bearing or setting up new equipment, understanding how to install SAF pillow block bearings is essential for optimal performance and longevity.

What Is a SAF Pillow Block Bearing?

Before we jump into how to install SAF split-housed pillow block bearings, let’s take a look at some potentially confusing terminology:

• Mounted Bearings: Pre-assembled units combining bearings with housings, seals, and lubrication systems. SAF blocks are a subtype of mounted bearing optimized for heavy loads and misalignment. Learn more about preventing misalignment.
• Pillow Block: A pillow block is a mounted housing that supports a bearing, allowing it to support a rotating shaft.
• Plummer Block: The main difference between a plummer block and a pillow block is that plummer blocks are housings supplied without bearings, with the intent of the bearing being installed separately. The fundamental application of both types is the same.
• Split Spherical Bearing: Refers to bearings with a spherical outer ring and split inner/outer races. This design allows installation without disassembling adjacent components, reducing downtime.
• SAF: This refers to a specific style of pillow block housing (often made of cast iron), typically used with split spherical roller bearings. “SAF” isn’t a true acronym; it effectively refers to a Split-housing, Adapter sleeve, and foot-mounted bearing unit. It’s a standardized style in the industry and is often used in high-load, low-speed industrial applications. Here’s a breakdown of what “SAF” typically implies:
  • S = Split housing (the housing is split into two halves for easier bearing installation and maintenance)
  • A = Adapter sleeve mount (the bearing is mounted on the shaft using an adapter sleeve, rather than directly on the shaft)
  • F = Foot-mounted (the housing is designed to be bolted to a base or foundation, like a foot mount)

Required PPE & Tools to Install a SAF Split Pillow Block.

To begin, you’ll need the following tools:

• Feeler Gauge
• Spanner Wrench
• Small Punch & Hammer
• Ratchet and Socket

PPE should include:

• Steel-Toe Boots
• Safety Glasses
• Gloves

Your gloves must be clean to prevent contamination in the bearing. 

Step-by-Step SAF Split Pillow Block Bearing Installation Guide

Follow these steps to properly install a SAF split-housed pillow block bearing:

Preparation

1. Shaft Inspection: Clean the shaft with a light oil and wipe it clean. Then ensure the shaft is round, straight, and free of burrs. Verify that the diameter matches the bearing specifications. Using a marker or grease pen, mark the location where you need your bearing to sit on the shaft.
2. Open Carton: Remove your bearing parts from the carton, but do not open individual wrappings until you are ready to use them. This will prevent unnecessary contamination.
3. Mount Housing Base: Make sure your housing support plate is flat and bolt the housing base square to the shaft.
4. Check Radial Internal Clearance: Open the bearing packaging and measure the Radial Internal Clearance (RIC) using your feeler gauge. Set the bearing on a flat surface and try to get the largest possible size feeler gauge across the top of the rollers between the roller and the outer raceway.

   This should feel snug, but you should still be able to pull the feeler gauge straight out. Compare your result to the manufacturer’s mounting spec sheet.

Bearing Mounting on Shaft

1. Shaft Assembly: 

Slide these parts on the shaft in the following sequence:

1. Seal Ring
2. Adaptor sleeve–face the threading to the outside, facing the following parts. 
3. Bearing
4. Lockwasher–tangs out
5. Lock nut–face the chamfered face toward the bearing and hand-tighten it initially. 

 2. Clearance Adjustment:

• Use a jack to slowly lift the shaft off the bearing, removing the load and relieving pressure from the inner race of the bearing. Then, measure the mounted clearance with feeler gauges between the rollers and the outer raceway.
• Using the spanner wrench, tighten the lock nut in 1/8-turn increments, checking the clearance with a feeler gauge after each turn until the specified operating clearance is reached (refer to Schaeffler’s bearing reduction table below).

Bearing Tightening Example:
22216 Bearing
Average measured unmounted clearance = 0.072
Bearing clearance reduction = 0.045 to 0.06
Bearing maximum final clearance = 0.0072 – 0.045 = 0.0027
Bearing minimum final clearance = 0.0072 – 0.06 = 0.012

3. Locking Mechanism: Secure the lock washer by bending a tab into the lock nut’s grooves with the small punch and hammer. If none line up, tighten it until one does. Never loosen the nut during this process, and don’t go beyond the recommended mounted RIC.

Housing Assembly

4. Install Shaft Assembly: Make sure the housing is clean. Slowly lower the bearings and seals into position to fit into the housing base. If the bearing outer rings are misaligned, don’t force them back into position. Carefully work the bearing by turning and sliding. 

The C-spacer ring is not used for an expansion or floating unit, but is used for a fixed bearing.

5. Lubrication:

• Hand-pack the bearing with grease until it purges from the opposite side.
• Fill the housing base cavity to the shaft’s bottom level.

 

6. Housing Cap Installation:

Reminder: Housing bases and caps are not interchangeable. Keep them as matched sets.

First, grease the bearing seal grooves in the housing cap. Then, wipe the mating surfaces down before placing the housing cap over the bearing. Align the dowel pins with the lower half of the housing. 

Use a torque wrench to fully tighten the bolts to the torque specified for cast iron or steel housings. Use oil only on the bolt threads. 

Final Checks

7. Rotation Test: Rotate the shaft to check for seal binding. Realign the housing if resistance occurs.

8. Mounting Bolt Torque: Secure housing base bolts per the fastener grade.

Split Spherical Bearings: Time-Saving Advantages

Split spherical roller bearings reduce replacement downtime by 60–80% by eliminating steps like shaft disassembly or drive component removal. Key benefits:

• Simplified Process: Replace bearings without removing gears, couplings, or heavy shafts.
• Safety: Avoid crane use for component handling.
• Cost Efficiency: Minimize labor and equipment expenses.

Need more detailed instructions for SAF Split Pillow Block Bearing installation? Check out this great PDF from Schaeffler!

Consolidated Bearings SAF Split-Housed Pillow Block Bearings

Built for Strength, Designed for Versatility

Schaeffler’s SAF pillow block housings are engineered for exceptional performance in heavy-duty applications. Designed to handle demanding loads and operate reliably in harsh environments, these housings deliver robust support and adaptability.

Supporting shaft sizes from 1-7/16″ to 7-15/16″, they are compatible with a wide range of bearing options—making them an excellent solution across a broad spectrum of industrial uses.

Key Advantages

1. Versatile Compatibility
   Designed to fit both FAG spherical roller bearings (series 222..-K) and FAG split spherical roller bearings (series 222S), these housings are ideal for high-load, low-maintenance operations.
2. Material Flexibility
   Available in both gray cast iron and ductile cast iron, users can select the material that best matches their environmental and load requirements.
3. Complete Accessory & Sealing Options
   Each unit can be equipped with accessories like triple-seal rings, stabilizing rings, end covers, and grease fittings. Sealing options range from standard labyrinth seals to SuperTac II taconite seals for extreme conditions.
4. Optimized for Lubrication
   Engineered with dedicated grease input and discharge ports, these housings support efficient grease application. They are also suitable for oil lubrication systems featuring labyrinth seals, O-rings, and sump equalizer holes.
5. Precision Mounting & Stability
   Machined locating faces and clear housing markings ensure precise alignment and faster installation—helping reduce setup time and improve overall reliability.
6. Ready for Smart Upgrades
   With predefined mounting points for condition monitoring devices like FAG SmartCheck and integrated lubrication systems, these housings are future-ready for advanced performance tracking and maintenance automation.
7. Superior Strength & Longevity
   Designed using advanced CAD modeling, Schaeffler’s SAF housings are built to withstand extreme loads and harsh conditions—minimizing unplanned downtime and extending operational life.