4-Piece Steel C-Key Set, APU10 APU16 ER32 ER40 (ER)

Complete set: 4 C-shaped carbon steel wrenches (APU10, APU16, ER32, ER40) for removing collets and tightening nuts on machining centers, milling machines, and engraving machines. Secure grip: Matching openings (APU10 5mm, APU16 48mm, ER32 42mm, ER40 56mm) that engage in nut slots to prevent slippage during toolholder adjustments. Wide compatibility: Suitable for CNC toolholders, engraving spindles, chucks, bearing nuts, ER collets, and APU toolholders; ideal for machinists and maintenance technicians. Compact hook: Curved design for accessing tight spaces and removing recessed round nuts; small size for easy storage in a toolbox or drawer. Non-slip handle: Rubber coating for a comfortable grip and reduced vibration during extended use. hardened steel resistant to bending and deformation.