T. J. Davies Retention Knobs: Engineered for Strength, Precision, and Corrosion Resistance!

T. J. Davies Co. Inc. continues to set the standard in precision workholding solutions with its high-performance retention knobs, designed for superior durability, strength, and corrosion resistance. Manufactured from American-made 8620 alloy steel, these retention knobs undergo a rigorous machining, heat treatment, and quality control process to ensure exceptional performance in CNC machining and tooling applications.

Each retention knob is machined in-house using single-point threading to imperial (Class 2A UNC) or metric (Class G6) standards, ensuring precise thread engagement and balanced lead-in/lead-out at 180 degrees. After threading, components are heat-treated to 58-62 HRC and coated with hot black oxide to military specifications, providing enhanced corrosion resistance and long-term durability.

T. J. Davies ensures uncompromising quality control, with each retention knob undergoing:

• Magnetic particle testing to detect microscopic imperfections.
• Pull testing at 2.5 times the drawbar pulling force for maximum strength validation.
• Heat treatment to a case depth of 0.020″ to 0.030″, maintaining a core hardness of 40 HRC for added toughness.

Unlike 9310 alloy steel, which can become brittle over time, 8620 alloy steel hardens progressively, improving longevity and reducing the risk of premature failure. All retention knob surfaces are finished to 32 RMA micro or better (ISO Grade 6N), ensuring smooth engagement and precision fit.

With over 500+ standard styles available, T. J. Davies also offers custom retention knob manufacturing, either from supplied drawings or reverse engineering from existing parts. Full traceability is maintained, with certifications for every step in production to meet the strictest industry quality standards.

To prevent toolholder swelling, expansion, or premature failure due to overtightening, T. J. Davies provides torque guidelines with each retention knob. Proper installation is further supported by precision-manufactured sockets, available individually or in complete sets, ensuring correct retention knob installation for maximum performance.

Available through distributors nationwide, T. J. Davies’ retention knobs are built to exceed industry standards, offering unparalleled strength, precision, and reliability. Whether for high-speed CNC applications, demanding machining environments, or custom tooling solutions, T. J. Davies delivers engineered excellence for the modern machine shop.