Tooling Technology is always on the cutting edge of metallurgical science and innovation. This special new steel formula in our High-Strength Quick-Change Knobs offers more holding power and higher tensile limits for the most demanding industrial applications.

• PD500 Mega Knob = 2x Stronger! 
• Model PD438 Knob = 3.5x Stronger!
• PD250 Micro Knob = 4x Stronger!
• PD375 Mini Knob = 5x Stronger!*
  (* With New High-Strength PD375FHS Cylinder Lock)