Single ball catches can be used with a strike or without. In softer woods it may be advisable to use the strike. As a general principal always use the largest catch your material will accommodate, the larger the catch the better they feel and sound. The Brusso catches we sell are supplied with a cylindrical dome profiled strike. The idea behind this technological breakthrough was to eliminate contact between ball and wood. Up to this point the spring loaded ball either rode directly on its adjacent wood surface or over a thin metal strike. If the ball rides on the wood it will eventually impress a track into the wood fibers. If it rides on a strike this strike is inevitably visible aside from being tricky to fit. The Brusso domed strike is simply drilled opposite the catch and allows the ball to float in the door gap, ride up the gentle slope of the strike and drop into the divot machined into its top.
The need for this level of sophistication pre-supposes a problem when the ball is allowed to ride directly on wood. This may well be the case in soft woods after a considerable time but on hard woods the damage will negligible. Nevertheless the Brusso catches are the still the nicest available and can be used with or without strike.
A ball catch can be fitted in a variety of locations around a door without much trouble. Generally they will positioned in the lower edge of the door as far away from the hinges as possible. On very tall doors it might be a good idea to use a catch top and bottom.
A countersink bit makes the ideal indent for the ball. This indent can be accurately located if a sheet of carbon paper is laid on the wood and the door closed carefully. The end of the resulting black line will mark the center of your countersink. Drill a very shallow countersink to check for correct positioning, as you drill it deeper you can move its center significantly if adjustment is necessary.