Precision Lock Nuts
Precision lock nuts clamp a bearing inner ring against its shaft shoulder and stay put without a tab washer. Locking pins act radially on the thread, so nothing has to be bent and nothing projects into the airflow. SES holds the range as an authorised SKF distributor, covering thread Metric fine, to suit standard bearing seats; size span Small spindle shafts up to large machine tool arbors; locking Three or more radial pins, hex key driven; material Hardened steel, with stainless executions. Executions include pin-locking precision nuts (KMT series), stainless steel executions, nuts with axial locking screws, hook-slot drive form, among others. It is specified most often into machine tool spindle bearing stacks and ball screw support bearing clamping. Every part is genuine SKF through official channels, with designation, specification and options confirmed against your duty before it ships — supplied from Kolkata and our branch network, with breakdown cover that does not sit in an inbox.
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Supplying India’s Industrial Names.
From integrated steel plants to power utilities and EPC majors — the works that cannot afford a counterfeit part specify through SES.
Function
Axial clamping of precision inner rings
Locking
Radial pins or screws, no tab washer
Faces
Ground square to the thread
Reuse
Designed for repeated dismantling
Where it runs.
You will find Precision Lock Nuts in the parts of a plant where this particular duty actually occurs. In practice that means machine tool spindle bearing stacks, ball screw support bearing clamping, grinding wheel spindle assemblies, and equally rotary table and indexing head shafts, test rig and balancing machine arbors, pump and blower shafts where a keyway is unwanted. What links them is the duty rather than the machine name — function: Axial clamping of precision inner rings. If your installation is not on that list it matters less than you would think: the operating condition decides the specification. Send us the load, the speed, the running temperature and the environment it runs in, and we will match it to the right execution in the SKF range and confirm what is in stock.
Specify it against the duty.
Specification here follows the operating condition, not the catalogue. The assembly comes apart at every scheduled service — A pin-type precision nut. Tab washers work-harden at the fold, and the broken tab normally ends up inside the bearing. Shaft has no keyway and cutting one is not acceptable — A nut that locks on the thread itself rather than one that needs a keyway washer to hold position. Runout at the spindle nose is already at its limit — The precision class with ground faces, and check face squareness on the shaft before final torque. A cocked nut tilts the inner ring and the error multiplies down the spindle. Where two of those apply at once, specify for the harsher of the two — under-specifying is what puts the part back on the bench a month later. Send us the duty and we will confirm the execution.
Ordering this from SES.
Tighten the locking pins evenly and in sequence once the nut is home. Pins driven fully in one at a time distort the thread flank locally, and the nut will not run true the next time it goes on. Send the designation off the failed part and we will confirm the SKF equivalent and stock position.