# NTN 51109 Thrust Ball Bearing - 45 mm Bore, Single Direction, Straight Bore - MROSupply.com

***NTN 51109 single direction thrust ball bearing with 45 mm straight bore. Separable design for easy mounting and dismounting. For axial loads in one direction in machine tool spindles, clutches, and vertical shaft applications.***



## Product details:

- Catalog number: 51109
- SKU: 283322
- Price: ***$19.86*** Each
- Shipping: ***FREE SHIPPING***  ON ORDERS OVER $100
- Typically Ships in: 1 day
- Brand: [NTN Bearing](https://www.mrosupply.com/brands/ntn-bearing/)
- Category: 
    - [Ball Thrust Bearings](htts://www.mrosupply.com/bearings/ball-bearings/ball-thrust-bearings/)
    - [Ball Bearings](htts://www.mrosupply.com/bearings/ball-bearings/)
    - [Bearings](htts://www.mrosupply.com/bearings/)
- Unit of measure: each
- Weight: 0.302 lb


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


## Product attributes;

  
- Ball Material: Steel
  

  
- Ball material: Steel
  

  
- Bore Type: Round
  

  
- Bore type: Round
  

  
- Cage Material: Steel
  

  
- Cage material: Steel
  

  
- Cage Type: Pressed
  

  
- Cage type: Pressed
  

  
- Configuration: One
  

  
- d (in): 1.7717
  

  
- D (in): 2.5591
  

  
- D1: 1.8504 in
  

  
- d1: 2.5591 in
  

  
- Da max: 2.2441 in
  

  
- da min: 2.2441 in
  

  
- Dynamic Load Rating: 6250 lbf
  

  
- Dynamic load rating: 6250 lbf
  

  
- Enclosure: Open
  

  
- I.D.: 45 mm
  

  
- Limiting Speed - Grease: 3200 RPM
  

  
- Limiting speed - grease: 3200 RPM
  

  
- Limiting Speed - Oil: 4600 RPM
  

  
- Limiting speed - oil: 4600 RPM
  

  
- Material: High carbon chrome steel
  

  
- O.D.: 65 mm
  

  
- Operating Temperature Range: -40 to 250 °F
  

  
- Operating temperature range: -40 to 250 ºF
  

  
- Outside Ring Type: Straight
  

  
- Precision: ISO class 0
  

  
- r (in): 0.0236
  

  
- Radial Internal Clearance: CN
  

  
- Radial internal clearance: CN
  

  
- ras max: 0.0236 in
  

  
- Seal material: None
  

  
- Seal type: None
  

  
- Static Load Rating: 15500 lbf
  

  
- Static load rating: 15500 lbf
  

  
- T (in): 0.5512
  

  
- Type: Thrust Ball Bearing
  
## Product documents / software:

- [Drawing](https://documents.mrosupply.com/product_documents/50/48/5048886/1264_S_mICK0xq.png)
## Alternate products to `NTN 51109 Thrust Ball Bearing - 45 mm Bore, Single Direction, Straight Bore - MROSupply.com`:
- [SKF 51109 thrust ball bearing, 45mm bore (1.772 in ID, 2.559 in OD), sheet metal cage, bearing steel construction. Designed for axial loads in one direction, suitable for general industrial applications.](https://www.mrosupply.com/products/320242/as-markdown/)
- [FAG 51109 single direction thrust ball bearing with 45mm bore and 65mm OD. Designed for axial loads in one direction, this bearing offers reliable performance in vertical shaft applications. Manufactured by Schaeffler, it meets ISO precision standards for industrial machinery.](https://www.mrosupply.com/products/2171488/as-markdown/)
- [NSK 51109 thrust ball bearing with 45 mm bore. Designed for pure axial loads in vertical-shaft applications. Backed by NSK's precision-bearing engineering heritage.](https://www.mrosupply.com/products/5032802/as-markdown/)
- [Rollway 51109 45 mm Bore Size, 65 mm Outside Diameter, Thrust Ball Bearing, 52100 Bearing Steel, Normal Radial Clearance](https://www.mrosupply.com/products/2302263/as-markdown/)






## 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.


- What is the difference between deep groove and angular contact ball bearings?: Deep groove ball bearings are the most common type. They’re designed to handle mainly radial loads, but they can also take some axial load in both directions. They’re simple, versatile, and used in everything from motors to conveyors.
Angular contact ball bearings are built for combined loads, especially where there’s significant axial force in one direction. They’re often used in pairs and are common in higher precision or higher load applications like pumps and gearboxes.
If your load is mostly radial, go deep groove. If axial load matters more, angular contact is usually the better choice.