# Position Preload Versus Constant-Pressure Preload on Spindles

Position preload sets a fixed axial stack through spacers or locknuts. Constant-pressure preload uses springs so load stays steadier as temperature rises. Position systems give high stiffness for finishing; spring systems forgive thermal growth on longer duty cycles. Mixing the two without redrawing the stack is a common rebuild error.

TFL Bearing walks through position versus constant-pressure choices with calculation cues. See spindle bearing preload calculation before you change spacer length or spring force.

Shandong TFL Bearing Co., Ltd publishes these notes so design and shop floor share one preload vocabulary.