# Timken QAAPR18A303ST Spherical Roller Mounted Unit, 2-Bolt Pillow Block - MROSupply.com

***Timken QAAPR18A303ST spherical roller mounted unit in a two-bolt pillow block housing. Designed for heavy-duty applications requiring self-alignment and high load capacity, such as conveyors, fans, and industrial gearboxes. Features a spherical roller bearing insert for combined radial and axial loads.***



## Product details:

- Catalog number: QAAPR18A303ST
- SKU: 5983511
- Price: ***$891.96*** Each
- Shipping: ***FREE SHIPPING***  ON ORDERS OVER $100
- Typically Ships in: 1 day
- Brand: [Timken](https://www.mrosupply.com/brands/timken/)
- Category: 
    - [2-Bolt Pillow Block Bearings](htts://www.mrosupply.com/bearings/mounted-bearings/mounted-roller-bearings/pillow-block-bearings/2-bolt-pillow-block-bearings/)
    - [Pillow Block Bearings](htts://www.mrosupply.com/bearings/mounted-bearings/mounted-roller-bearings/pillow-block-bearings/)
    - [Mounted Roller Bearings](htts://www.mrosupply.com/bearings/mounted-bearings/mounted-roller-bearings/)
    - [Mounted Bearings](htts://www.mrosupply.com/bearings/mounted-bearings/)
    - [Bearings](htts://www.mrosupply.com/bearings/)
- Unit of measure: each
- Returns: Yes


## Product images:
- https://static.mrosupply.com/images/noimage.webp


## Product attributes;

  
- 0.060 mm Shaft Size: 3 3/16 in Shaft Tolerance:0.0030 in
  

  
- 0.076 mm Shaft size type: Imperial Y1 - Geometry Factor:2.90 Y2 - Geometry Factor:4.31 e - Geometry Factor:0.23
  

  
- 0.100 mm Pre Install Clearance Min: 0.0024 in
  

  
- 131.6 mm Eng Internal Radial Clearance - Max: 0.0039 Eng Internal Radial Clearance - Min:0.0024 Engineering group:Mounted Bearing Float:0.083 in
  

  
- 20 mm Dimension RAA: 0.84 in
  

  
- 21.3 mm Dimension SAA: 5.18 in
  

  
- 235 mm Dimension J (Bolt Size): 0.75 in
  

  
- 285.8 mm Dimension D Min: 9.25 in
  

  
- 95.3 mm Dimension D Max: 11.25 in
  

  
- Bearing number: 22218 C - Dynamic Load (Basic):79700 lbf 355000 N C0 - Static Load:87200 lbf 388000 N Dimension:3.75 in
  

  
- Bearing Number: 22218
  

  
- Dynamic Load (Basic): 79700 lbf
  

  
- Eng Internal Radial ClearancMax: 0.0039
  

  
- Eng Internal Radial ClearancMin: 0.0024
  

  
- Engineering Group: Mounted Bearing
  

  
- Float: 0.083 in
  

  
- Geometry Factor: 4.31
  

  
- Grease Lubrication - B/C/O Seal: 1000 rpm
  

  
- Grease Lubrication - M/N Seal: 1400 rpm
  

  
- Grease Lubrication - T Seal: 2000 rpm
  

  
- Housing Construction: Four-Bolt Pillow Block
  

  
- Locking Style: Double Concentric
  

  
- Oil Lubrication - B/C/O Seal: 1000 rpm
  

  
- Oil Lubrication - M/N Seal: 1400 rpm
  

  
- Oil Lubrication - T Seal: 2400 rpm
  

  
- Pre Install Clearance Max: 0.0039 in
  

  
- Pre Install Clearance Min: 0.0024 in
  

  
- Shaft Size: 3 3/16 in
  

  
- Shaft Size Type: Imperial
  

  
- Shaft Tolerance: 0.0030 in
  

  
- Static Load: 87200 lbf
  
## Product documents / software:

- [Double Concentric Four Bolt Pillow Block](https://documents.mrosupply.com/product_documents/59/83/5983511/qaapr18a303s_TN0fcxM)

## Product's reviews:
- Best company to buy from - I always buy from MRO is a very reliable company to work with




## FAQ:

- How do I choose the right type of bearing for my application?: Start with the load and how it’s applied. You need to know if you’re dealing with radial loads, axial loads, or a mix of both. Then look at speed, operating environment, and space constraints.
For example, ball bearings are great for high speed and lighter loads, while roller bearings handle heavier loads but usually at lower speeds. If there’s contamination, moisture, or heat involved, you may need sealed bearings or specific materials.
In most cases, the right choice comes down to matching load type, speed, and environment to the bearing design.