How to Replace the Left Knife on a DeWALT Shear

There are three knives in your shear's cutter-head: two outer knives and a center blade. The left knife is one of the outer knives. The outer knives are fixed. The center blade pivots up and down between them. Over time, the knives will wear. When this happens, the shear won't cut cleanly, or it might jam with metal between the cutters. If the shear is dropped, the knife might be cracked, bent or broken.

Let's get started.

REMOVING THE LEFT KNIFE   1. Remove the blade assembly.

a. Use a hex wrench to remove the two front screws from the cutter-head.

b. Use a hex wrench to loosen the rear screw securing the cutter-head.

c. Pivot the blade assembly out of the cutter-head and remove the (3) blades and the (2) inserts from the unit.

INSTALLING THE NEW LEFT KNIFE

  2. Install the blade assembly.

a. Install one of the spacers into the center blade.

b. Position the new left knife and the right knife against the center blade (the beveled portion of the outer knives should face the top of the shear).

c. Install the blade assembly into the cutter-head.

d. Align the rear fork on the center blade with the eccentric inside the gear housing.

e. Install (and partially tighten) the front screw.

f. Pivot the outer knives (as necessary) to align the mounting holes (on each knife) with the center hole on the cutter-head.

g. Install the second spacer into the center hole on the cutter-head. The spacer should pass through the rear holes on both of the outer knives.

h. Install and tighten the center screw.

i. Tighten the remaining two screws to secure the blade assembly to the cutter-head.