Mounting Methods (Part 1 of 4): Setscrew Locking

(This is the first of a four-part series examining the Four Shaft Attachment Methods for Mounted Ball Bearings…)


PTI offers all four (4) shaft locking mechanisms for mounted (aka “housed”) ball bearings:

  1. Setscrew Locking
  2. Eccentric Locking Collar
  3. Concentric Clamp Collar
  4. Tapered Adapter Sleeve

setscrew closeup image for blog.png

Let’s examine the first option: The Setscrew, also often referred to as “Setscrew Locking,” is the most popular locking mechanism for securing a mounted bearing to the shaft. Read on to learn more…


setscrew contact points.jpg

  • Easy to Install
  • Lowest Purchase Price
  • Clearance Fit
  • Moderate Shaft Damage*
  • Low to Medium Speed

*Note: this shaft attachment method can cause fretting corrosion, making removal difficult after years of operation

Starts at 02:20

  • After the shaft is aligned, tighten both set screws by hand
  • Then tighten the set screws alternately until the torque is reached (see Chart 4 below)
  • After 24 hours of operation, check the set screw torque and re-tighten if/as needed to ensure full locking to the shaft

setscrew locking chart 4.PNG


  • Wrenches should be kept in good condition (flats not rounded over) to prevent damage to the set screws and to allow proper tightening.
  • Set screws can be replaced to maintain holding power without replacing the entire bearing.
  • L10 Life = the expected life of the bearing under normal conditions. Factors affecting bearing life include temperature, ambient conditions (presence of moisture, dust, dirt and other contaminants) and lubrication/maintenance practices.


Click here to access Part Two: The Eccentric Locking Collar, Part Three: The Concentric Clamp Collar and Part Four: The Tapered Adapter Sleeve.

* * *

About PTI: Upon opening in 1994, PTI has specialized in serving the growing niche market of Metric products. As demand has increased over the years, so has our product offering. Today, our customers enjoy a huge offering of both Metric and Inch-based products for the Industrial Power Transmission Industry.

Want to learn more about PTI? Click here to view our company overview video. Check out other videos, information and more at

3 thoughts on “Mounting Methods (Part 1 of 4): Setscrew Locking

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