Chagrin Falls, OH — For contract machine shops and OEMs that rely on CNC milling machines, T.J. Davies retention knobs utilize superior U.S. steel to enhance setup rigidity, while improving tool life and cycle times.
Poorly designed retention knobs from overseas are often made of low-quality steel that may be prone to breaking during machining. Newer CNC milling machines exert significantly more drawbar pressure on retention knobs than in the past. As drawbar tension continues to increase in CNC machines, it puts so much pressure on the retention knob that it may be more likely to break if not manufactured to the highest standard.
T.J. Davies manufactures high-quality retention knobs that utilize certified 86L20 and 9310 steel drawn in the United States. 86L20, a low alloy nickel, chromium, molybdenum case hardening steel, has high hardenability without temper brittleness, along with good external and internal strength, and high wear-resistance.
However, if a CNC operator requires an even higher quality steel, they can choose a retention knob made of 9310, a low alloy steel composed mostly of nickel and chromium. This alloy also has high hardenability, core hardness and fatigue strength, which makes it an excellent steel for use in heavy-duty machinery.
For long-term reliability, each retention knob is coated with black oxide to prevent corrosion. In this process, the top layer of the ferrous material is treated with chemicals that convert the surface to prevent rust. Black oxide also increases abrasion resistance, while providing a decorative finish.