# Koyo 6903 Deep Groove Ball Bearing - 17 mm Bore, Open Type, 30 mm OD - MROSupply.com

***Koyo 6903 is a 69 series single-row deep groove ball bearing with a 17 mm bore, 30 mm OD, and 7 mm width. Open type design for applications requiring low friction and high-speed operation. Suitable for electric motors, pumps, and general industrial machinery.***



## Product details:

- Catalog number: 6903
- SKU: 1495164
- Price: ***$30.68*** Each
- Shipping: ***FREE SHIPPING***  ON ORDERS OVER $100
- Typically Ships in: 1 day
- Brand: [Koyo Bearing](https://www.mrosupply.com/brands/koyo-bearing/)
- Category: 
    - [Single Row Angular Contact Bearings](htts://www.mrosupply.com/bearings/ball-bearings/angular-contact-ball-bearings/single-row-angular-contact-bearings/)
    - [Angular Contact Ball Bearings](htts://www.mrosupply.com/bearings/ball-bearings/angular-contact-ball-bearings/)
    - [Ball Bearings](htts://www.mrosupply.com/bearings/ball-bearings/)
    - [Bearings](htts://www.mrosupply.com/bearings/)
- Unit of measure: each
- Weight: 0.017 lb
- UPC: 60579008594


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


## Product attributes;

  
- Ball Material: Steel
  

  
- Bearing Type: Radial
  

  
- Cage Type: Metal
  

  
- Contact Angle: 0
  

  
- I.D.: 17 mm
  

  
- icNumber: 7696809
  

  
- Inch/Metric: Metric Bore
  

  
- Inner Ring Width: 7 mm
  

  
- Locking Device: No Locking Device
  

  
- Lubricant: Oil Preservative
  

  
- Material: Steel
  

  
- No. in Set: Single Bearing
  

  
- O.D.: 30 mm
  

  
- O.D. Type: Straight
  

  
- Origin: Single Row Radial
  

  
- Outer Ring Width: 7 mm
  

  
- Precision: Standard
  

  
- Precision Level: Standard (ABEC 1)
  

  
- Rows of Balls: Single
  

  
- Seal Type: Unsealed
  

  
- Snap Ring: No Snap Ring
  

  
- Width: 7 mm
  
## Product documents / software:

- [drawing](https://documents.mrosupply.com/product_documents/68/6802/010_1.jpg)
## Alternate products to `Koyo 6903 Deep Groove Ball Bearing - 17 mm Bore, Open Type, 30 mm OD - MROSupply.com`:
- [NTN 6903 is a single-row deep groove ball bearing with a 17 mm straight bore. This open bearing has no seals or shields, making it suitable for high-speed applications where relubrication is required. It is commonly used in small electric motors, power tools, and precision instruments.](https://www.mrosupply.com/products/283897/as-markdown/)
- [Nachi Bearing 6903 Deep Groove Ball Bearing Open](https://www.mrosupply.com/products/207812/as-markdown/)
- [SKF 61903 deep groove ball bearing, 17mm bore, open design with sheet metal cage. Bearing steel construction. Suitable for high-speed operation in electric motors, pumps, and general industrial applications.](https://www.mrosupply.com/products/326298/as-markdown/)
- [NSK 6903 deep groove ball bearing with 17 mm bore and 30 mm outside diameter. Open design with no seals or shields, pressed steel cage, and normal clearance. Suitable for electric motors, pumps, fans, and general industrial applications.](https://www.mrosupply.com/products/5034622/as-markdown/)

## Product's reviews:
- Great service - great items at great price
- Admin assistance - good product!
- Koyo roller bearing inner ring - Good product.




## 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.