Value Collection CNFI5125-015BX Castle Lock Nut 1-1/4-12

Product Description

The VALUE COLLECTION CNFI5125-015BX is a castle lock nut machined from Grade 5 steel with a bright, uncoated finish. It features a 1-1/4-12 UNF thread size, a right-hand thread direction, and conforms to ANSI B18.2.2 dimensional standards. The castellated crown accepts a cotter pin or safety wire, providing positive locking in high-vibration or safety-critical applications. At 1-1/4 inches in height with a 1-7/8-inch width across flats, it is sized for medium-to-large fastener assemblies. Machinists, millwrights, and maintenance technicians install this type of nut wherever a standard hex nut lacks the retention needed to prevent loosening under dynamic load.

Castle lock nuts in this thread class are commonly used in mechanical power transmission assemblies, bearing retention, shaft-end applications, and industrial equipment maintenance. The 1-1/4-12 fine thread pitch provides higher thread engagement per inch compared to coarse-thread variants, which improves axial holding force and reduces the likelihood of backing off under cyclic or shock loading. This part is sold individually and is appropriate for both new installation and replacement service work in industrial and heavy-equipment environments.

Key Features

• Castellated crown design accepts a cotter pin or safety wire for positive mechanical locking
• 1-1/4-12 UNF fine thread for increased thread engagement and axial holding force
• Grade 5 steel construction provides tensile strength suitable for medium-duty structural and mechanical applications
• Bright, uncoated finish — no plating that could interfere with close-tolerance fits
• Right-hand thread direction, conforming to ANSI B18.2.2 dimensional standards
• 1-1/4 inches height and 1-7/8 inches width across flats for use with standard open-end or box-end wrenches

Compatibility

Designed as an ANSI B18.2.2-compliant castle lock nut for use with 1-1/4-12 UNF threaded fastener assemblies in industrial, mechanical, and maintenance applications.

Installation Notes

Installation is performed by millwrights, maintenance mechanics, or other qualified technicians using a standard open-end, box-end, or socket wrench sized for a 1-7/8-inch across-flats nut. De-energize and lock out all equipment before working on any rotating or load-bearing assembly. After torquing the nut to the assembly specification, align the nearest castle slot with the cotter pin hole in the shaft and insert an appropriately sized cotter pin or safety wire to secure the nut against rotation. Never reuse a cotter pin that has been previously bent.