Adjustable-length hand deburring tools reach into recesses to smooth rough edges around holes, countersinks, and straight edges and remove projections that can cause parts to be out of tolerance, which negatively affects how parts fit together. Blade holder length can be changed in small increments to provide knuckle clearance and get to hard-to-reach areas. Blades are shaped for different cutting angles and applications and are often replaced when they become dull.