Forty-Five° Lock Miter Cutter Heads694. 011 CMTs lock miter cutter heads are ideal for milling miter joints in stock a maximum of 28mm in thickness. Create boxes, stretcher bars, frames and any assortment of right angle (90) or parallel joint projects. Two easy steps to produce perfect fitting 45 miter joints: first, position and mill your workpiece horizontally, then vertically. Create parallel glue joints in two steps: position and mill your workpiece horizontally, internal side