Mak-a-key 7003120312-12 Undersized Key Stock 18-8 Ss

Product Description

The MAK-A-KEY 7003120312-12 is an undersized key stock bar used to secure rotating components - such as pulleys, gears, and sprockets - to shafts in mechanical drive systems. Measuring 5/16 inches high by 5/16 inches wide by 12 inches long, this piece is fabricated from 18-8 stainless steel, which provides corrosion resistance in wet or chemically exposed environments. The undersized profile allows for controlled fit tolerances in keyways where a standard key would bind. Machinists, millwrights, and maintenance technicians cut this stock to the required length for their specific application.

Undersized key stock is commonly used in HVAC drive assemblies, pump shafts, fan blade hubs, and light industrial power transmission systems. The 5/16 inch square cross-section fits keyway slots sized for that nominal dimension where a slightly reduced tolerance is needed. A single 12-inch length provides enough material to yield multiple cut-to-length keys from one piece, making it practical for service shops and field technicians who stock raw key material for on-demand fabrication.

Key Features

• 18-8 stainless steel construction resists corrosion in humid and chemically active environments
• Undersized profile provides controlled clearance fit in standard 5/16 inch keyways
• 12-inch length can be cut to yield multiple keys per piece
• Square 5/16 inch x 5/16 inch cross-section suits common shaft keyway dimensions
• Single-piece packaging suitable for low-quantity service and repair needs

Compatibility

Designed as an undersized replacement or fabrication-stock key for mechanical drive shafts and hubs requiring a 5/16 inch square keyway with a reduced-tolerance fit.

Installation Notes

Installation is performed by machinists, millwrights, or qualified maintenance technicians. De-energize and lock out all power to the drive system before removing or installing any shaft key. Cut key stock to finished length using a bandsaw, cold saw, or appropriate metal-cutting tool, then deburr all edges before fitting. Do not use oversized hammer blows to force the key into the keyway, as this can damage the shaft or hub bore.