To build a storage box for pocket knives, begin by cutting two pieces of 3/4-inch plywood that fit the length and height you want the box to be. Next, cut two pieces of 3/4-inch plywood to the width you have chosen.
Cut another piece of 3/4-inch plywood for the top of the box that fits the length and the width you have chosen for the box. Cut the bottom of the box 1/2 inch shorter and 1/2 inch smaller in width than the top to fit inside the side pieces of the box. Using a jigsaw, cut grooves into the front, back and side pieces that are 1/4 inch deep, 3/4 inch wide and 1/2 inch from the bottom edge of each piece. Sand each piece to remove roughness.
Line up the edges and grooves of the front and back of the box, and secure them to one of the two side pieces using wood screws. The bottom piece should slide into the grooves on the three secured pieces. Secure the remaining side of the box. All that is left to attach is the top of the box.
Use putty to fill in the holes made by the screws, and paint or stain the outside, basin and top of the box. Attach hinges to the top piece and the back piece with 3/8-inch wood screws. Secure an overlapping locking hasp to the top piece and the front piece. Add any desired decorative pieces, such as brass corners.