Countersunk magnets, also known as round cup or cup magnets or channel magnets, are built up with one or two 90° holes to fit in a standard flat-head screw. These are N35 neodymium magnets with optional steel cup on it. Countersunk versions offer the added benefit of easy stitching and easy installing, the screw hole puts the magnet to stick on any surface other than a self adhesive version, and absolutely with flush, sleek and secure exterior.
These are the magnets mostly used on furniture fixings, artwork securing, door accessing control, tools holding, automotive components, etc. You don’t need a super strong magnet with high pull force on a countersunk option, and there won’t be a countersunk magnet with big size at all, but a precise size and the purpose to use with the countersunk magnets should be clearly noted.