A detent is the click you feel as a knob, dial or hinge passes set positions. Mechanically it is usually a spring-loaded ball or leaf riding over notches, which wears, can loosen, and changes feel over time.
Patterned magnets can produce the same click with no contact. Two faces printed with matching repeating patterns pull toward the positions where the patterns line up and resist the positions in between. Correlated Magnetics Research's catalog has detent Polymagnet pairs with 12 positions at 30 degree spacing in a 1 inch D-shape, offered with M4 or #6 countersinks, a 4-position 90 degree pair, and a drawer detent pair for linear motion. Its align design note says custom pairs can have almost any angle and number of positions.
Detents can also be combined with sensing. In a 2015 press release on its site, CMR described a dimmer built with AKM Semiconductor in which a single round magnet carried an outer ring pattern read by a rotational Hall-effect sensor and inner rings that gave a tuned detent feel at set positions.
Because there is no rubbing contact, the feel should not drift with wear, and the mechanism can sit behind a sealed wall. Expect lower holding torque than a stiff mechanical detent of the same size, and check torque against your knob inertia.
WholeMagnetics, 2026-10-04. Polymagnet facts are taken from Correlated Magnetics Research’s public pages, listed below; vendor performance figures are CMR’s own.