Mortise Lock Installation Made Easy With the HIT-66-200 Tool

May 1, 2013
Without specialty tools, creating a mortise pocket on a wooden door is slow and tedious. Having the right tools available saves time and make the job look professional.

Mortise locks require a pocket, created in the edge of the door. The pocket is centered within the edge of the door ranging in size from ¾" to approximately 1 inch thick. The height of the pocket is determined by the lock’s application and manufacturer.

Mortising a pocket into the edge of a wooden door is difficult and time consuming because precision work is required. For example, cutting the mortise lock pocket in an interior wooden door will leave about ¼" wood on each side of the pocket - not much room for error.

There are two practical methods for creating a mortise pocket on a wooden door:

  1. The manual method of using a brace and bit to create the mortise
  2. Using a tool specifically designed for creating the mortise pocket.

Free styling with a handheld power drill on a wooden door can result in the drill bit breaking through. The electric drill drives the bit too fast to keep the bit straight and prevent movement resulting from knots, etc. If the door is to be painted, body filler can often be used to repair the damage. If the door has a stain or clear finish, you just bought a new door.

For this reason, I used a brace and auger bits to mortise the pocket in a wood door. The tip of an auger bit is threaded. As the wood is cut away, the tip continues to screw into the wood maintaining the proper direction. Even if there is a knot or hard spot, the slowness of the cut permits the tip to keep screwing straight. This is a tedious and time consuming method for creating the pocket.

Once the six to eight holes have been drilled into the door, the next step is to use a chisel and wood rasp to remove the excess material for the mortise to slide into the pocket. The average installation time using a brace and bit is nearly three hours.

Major Mfg. has provided a better way. Their HIT-66-200 Lock Mortiser creates the mortise pocket in a wood door. The mortiser comes with a 1” carbide tip mortise bit, mortise guide plate for alignment and stop collars.

The HIT-66-200 can be used to cut out a pocket for an auxiliary mortise lock as well as a full-sized mortise lock. The pocket can be cut up to 5-1/2" deep by 8-1/2" tall.

The HIT-66-200 Lock Mortiser is used in conjunction with the HIT-66 Clamp System. The HIT-66 system is designed to be used with additional components including templates to properly locate the pocket and the openings in order to prep a door.

For this article, we installed a Schlage Entrance Mortise Lock into a wood mount. The Schlage lock case is 5-15/16” tall. The mortise pocket will be a bit over 6-1/2” tall to compensate for the curvature at the top and bottom of the pocket.

A pan head screw is attached to the case and extends beyond the one-inch width of the case. Use wood rasp to enlarge to the pocket to accommodate the screw head.

Important: Before installing any door hardware, be sure to wear ear and eye protection. Know how to safely use power tools. Be sure all bits and cutters are sharp and in good condition.


To begin the installation, attach the lock mortiser to the HIT-66 Clamp System with the one-inch carbide tipped cutting bit. Attach the HIT-66-282 Schlage L Series template, completing the hardware in order to mortise the pocket and drill the openings.

It is important to attach the alignment guide and the spacing clamps before mounting the tool onto the door. The alignment guide is used to gauge the center of the mortise pocket. The spacing clamps are located along the top and bottom of the rod guides and limit the travel of the drill unit. They can be adjusted to the specific lock model. Mount the clamps towards the rear of the tool in order to permit fine adjustment.

The mortiser is ready to be mounted. Evenly tighten the top and bottom clamps to ensure proper door prep. Draw a line across the center of the mortise pocket from edge to edge. This line will be used to locate the tool if it is removed before completing the installation. In addition, this line will be used to locate the hardware for routing the faceplate.

Using the mortise case as a guide, adjust the position of the depth clamp on the bit shank to determine the depth of cut.

Be sure to bring a shop vacuum to collect the debris, keeping a clean work area.

Begin cutting the mortise pocket at the bottom. Drill the first hole. This way, the debris falls down into a hole that has already been drilled and does not clog the hole being drilled.

After every inch drilled, back out the bit to clear the chips. Do not attempt to drill any hole to depth all at once. Use a moderate drill speed of 350 to 500 rpm.

Drill each additional hole directly above the previously drilled hole.

For this installation six holes were drilled, leaving some webbing between each hole. Remove the webbing after the six holes have been drilled.

The mortising bit is also designed to remove the material between the drilled holes.

Before drilling any of the lock function holes, make sure the mortise bit is out of the pocket. Once the mortise pocket has been drilled to size, drill the lock function holes.

HIT-66-282 templates provide the locations for the lock hardware. Drill the holes for the spindles, thru bolts, mortise lock cylinder and thumbturn. Once drilled, remove the tool.

To finish the mortise pocket, use an 8” wood rasp to smooth the walls and remove any excess debris. Slide the mortise case into the pocket. Check to be certain it slides in smoothly and the location holes align with the lock.

We cut out the faceplate for the Schlage mortise lock with the Major Manufacturing HIT-45 clamp and HIT-45AR5 template.

Having the right tools available saves time and make the job look professional. The installation was completed in less than one hour.

For more information, contact your local locksmith distributor or Major Manufacturing Inc., 1825 Via Burton,Anaheim,CA92806. Telephone: 714-772-5202. Web Site:

To read additional Locksmith Ledger articles on installing mortise locks, visit