Toolholder “pull studs,” or retention knobs, are meant to be replaced. Inspect and Replace them regularly.
Watch for damage.
In particular, watch a retention knob for damage under the head, where the gripper fingers or balls make contact.
Depressions, cracks and scuff marks are all danger signs.
A small amount of wear on knobs can significantly reduce the drawbar force. Damaged knobs can result in damage to the gripper mechanism.
However, even if knobs show no damage,they should be replaced within 2 years. This replacement represents a cheap insurance policy for an expensive machine tool.
Retention Knob HQ proudly distributes Proven Quality Retention Knobs - 100% manufactured in USA by TJ Davies Co.(Chagrin Falls, OH)
Certified Tolerance Exceeds Industry Standards
Finish 32 Micro or Better
Coolant Holes Super Finished (.200 or Larger)
Coolant Holes No Carbed (Masked)
Heat Treat Carburized (Hardened)
About Our Supplier - TJ Davies Co. (in the owner's words)
Our family-owned and operated company was founded in 1965 as Deb-Sher Machine.
Since 1975, T. J. Davies Company has been manufacturing our own line of retention knobs.
Our high-quality steel is rolled in the USA, and all manufacturing is done in our plant located in Chagrin Falls, Ohio.
Our retention knobs are known throughout the industry as second-to-none, and they can be easily recognized in their famous blue tubes.
My Dad, Thomas Jared Davies passed away last year (2019) so I am second generation; we are now certified as a women owned business.