FafnirFPN19Precision Bearing Lock Nut – Fafnir FPN Series, Size 19, Ground Clamping Face

Product Description

What this part is

Fafnir FPN19, a precision bearing lock nut from Timken’s Fafnir FPN spindle range. Material: Steel. Series: FPN. Base Number: FPN19.

Decoding the designation

FPN — Fafnir precision nut, the spindle-grade lock nut range, ground so the clamping face runs square to the thread.

19 — the size code in the FPN range, which sets the thread and the pilot.

What these specs mean in practice

A precision lock nut clamps the inner ring stack of a spindle bearing set against the shaft shoulder and sets the preload. The clamping face is ground square to the thread axis, so tightening the nut pushes the inner ring on squarely instead of cocking it, which is what keeps the running accuracy of a P4 or P4S bearing set intact after assembly. An ordinary KM-style locknut and tab washer does not hold that squareness, which is why spindle builders specify the precision range.

Quantity and configuration

Unit Quantity: 1 Pc. One lock nut.

Interchange guidance

Precision lock nuts are made to each manufacturer’s own thread, pilot and face specification, so no like-for-like interchange is published for this part. Match a replacement on thread size and pitch, outside diameter, overall height and clamping face flatness. Searchable variants include FPN19, FPN-19, FPN 19 and F-PN-19.