The 1/2-inch fixed-width double-bevel mortise blade is the largest of the fixed-width blades available for the Tite-Mark or Tite-Mark Long. Just slide it on and lock it down. Although the single-bevel mortise blades can be adjusted to layout a 1/2-inch mortise and tenon, this fixed-width blade greatly simplifies the task, especially if you are looking for absolute consistency.