how to fit a mortise lock hello and welcome to videojug we're going to show you how to fit a mortise lock this is a particularly secure lock that's difficult to force open because it's fitted into the side of the door step one you will need a battery drill kit complete with drill bits most importantly flat wood cutting bits like this one a mortise lock kit which includes the lock body and key the strike plate faceplate and key covers screws a chisel tape measure pencil hammer masking tape some sandpaper safety goggles and a dustpan and brush in case of any mess step 2 mark the lock position decide on a height for your lock use your tape measure to find the center point on the side of the door mark it with a pencil and draw a longer vertical line through the point hold the lock flat against the door edge at your chosen height and draw around it with your pencil step three select a drill bit select a flat drill bit that is roughly two millimeters or 1/16 of an inch thicker than the lock body this will ensure a comfortable fit hold the lock against the drill bit use the masking tape to mark the depth of the lock on the bit and attach it to the drill step four drill out the lock recess before you start drilling remember your drill safety put on your goggles make sure all loose items of clothing jewelry and hair are tucked away clear the area of any potential hazards and find a steady standing position start just beneath your top pencil mark and drill a series of overlapping holes down to your bottom pencil outline you may want to wedge the door open to help steady your drilling drill to the depth marked and take care to keep the bit horizontal and square to the door edge step 5 straighten up the edges before you pick up your chisel remember your chisel safety make sure that you are wearing safety goggles and clear the area of potential hazards find a steady position and remember to watch your fingers when you do start chiseling firstly clear out any wood chippings with the chisel then use your chisel to tidy up the edges of the mortise recess so that the mortise will fit keep the flat edge of the chisel facing outwards as you work and chisel to the depth of the recess scrape out any wood chips step six mark the faceplate now slide the lock into the recess and place the faceplate over it draw around it step 7 make a recess for the faceplate begin by making a series of cuts on the edges of your pencil outline like this now chisel out the rest of the recess keep testing the fit to see that the faceplate lies flush with the door be careful because if you chisel out to large recess it will be difficult to correct step 8 mark the keyholes hold the lock against the face of the door so that the plate is flush with the door edge mark through the keyhole with your pencil then did the same on the other side of the door step 9 drill the keyholes select a drill bit that is slightly larger than the keyhole and insert it into your drill remember your drill safety drill along the pencil line through to the lock recess repeat this on the other side of the door step 10 test the keyhole insert the mortise into its recess and check that the key works smoothly step 11 attach the face plate you may want to draw small pilot holes for these screws but in most cases you can drill them straight in step 12 fit the keyhole cover hold the cover over the keyhole and roll it into place repeat this on the other side of the door step 13 mark the bolt position on the frame turn the key to extend the bolt push the door to and draw around the bolt on the frame step 14 mark the strike plate position measure the distance between the inside edge of the door and the strike plate mark this measurement on the doorframe align the strike plate with the pencil line you have just made the bolt recess must be positioned according to the marks on the edge of the frame draw in and around the strike plate step 15 cut the strike plate recess remember your chisel safety following your marks chisel out a hole for the bolt first cut around your pencil outline then chisel out the recess check the fit of the bolt in the recess then chisel out a shallow recess for the strike plate so that it lies flush with the doorframe be careful not to chisel out to deeper recess as this will be hard to undo keep testing the plate until it fits snugly step 16 attach the strike plate remember your drill safety draw the strike plate into the frame step 17 test now test your handiwork check the door closes easily and the key turn smoothly done you