HHIP 3900-1627 5C Expanding Collet, 0.250-0.468" Size .250-.468" (#1) Size Range: 0.250" - 1.937" Concentricity within .0005" . Shoulder widths within .001" Size Range: 0.250" - 1.937" .Effective expansion up to .006" Fits any standard 5-C spindle. EASILY MACHINED