Precision lock nuts with locking pins
KMT (fig. 1) and KMTA (fig. 2) series precision lock nuts have three locking pins, equally spaced around their circumference, with their axes parallel to the loaded thread flank (fig. 3). When tightened, the locking pins preload the threads, which provides sufficient friction to prevent the nut from loosening under normal operating conditions (→ Loosening torque).
KMT and KMTA lock nuts are intended for applications where high precision, simple assembly and reliable locking are required. The three equally-spaced locking pins enable these lock nuts to be accurately positioned at right angles to the shaft. However, they can also be adjusted to compensate for slight angular deviations of adjacent components (→ Installation and removal).
KMT and KMTA lock nuts should not be used on shafts or adapter sleeves with keyways or key slots. Damage to the locking pins can result if they align with a keyway or slot.
Both lock nut series are available standard with a thread up to 200 mm (size 40). KMT lock nuts with a thread ranging from 220 to 420 mm (sizes 44 to 84) can be supplied on request. For additional information, contact the SKF application engineering service.
KMTA lock nuts have a cylindrical outside surface and, for some sizes, a different thread pitch than KMT lock nuts. They are intended primarily for applications where space is limited and the cylindrical outside surface can be used as an element of a gap-type seal.