How Are Steel Strike Plates and Magnets Used Most Effectively?
Short answer
A steel disc, or strike plate, gives a magnet something to grab without the cost of a second magnet. For the best hold, use a plate slightly wider than the magnet and as thick as your design allows. Plates are great for latches, box lids, cabinet doors and banner stays because the magnet holds anywhere on the plate and there’s no polarity to get wrong.
Magnet Pair or Magnet + Plate?
Two Magnets
- Strongest hold for the size
- Self-centers into exact alignment
- Poles must face north to south
- Costs two magnets
Magnet + Steel Plate
- Lower cost per closure
- Holds anywhere on the plate, so small misalignment is fine
- No polarity to check
- Thin plates hold less than the magnet’s rating
For the numbers behind this, including how much more a pair holds through a gap, see is magnet-to-magnet stronger than magnet-to-steel?
Getting the Most Pull from a Plate
- Go slightly wider than the magnet, so the whole magnet face lands on steel even if alignment drifts.
- Use the thickest plate that fits. A thin plate saturates and can’t carry all of a strong magnet’s field, so pull drops. See does steel thickness affect magnet strength?
- Keep the gap small. Paint, fabric or adhesive between magnet and plate reduces holding power. See air gaps.
- Mount flat. A plate that rocks or flexes holds less.
Where Strike Plates Work Well
Cabinet and door catches, gift box and packaging closures, scrapbook and album covers, sign and banner stays, and closures on bags, holsters, curtains and tarps.