Precision Brand 56507 Mill Stock Key Stock 4 Pieces

Product Description

The PRECISION BRAND 56507 is a mill stock key stock bar used to transmit torque between a shaft and a mating hub, gear, pulley, or sprocket. Machined from low-carbon steel to ASTM A108 specifications, it measures 0.5 inches wide by 0.5 inches high by 12 inches long and ships with a plain, uncoated finish ready for cutting to final length on the job. Rockwell B80-90 hardness provides the shear resistance needed for standard power-transmission applications. Each package contains 4 pieces. Installation is typically performed by machinists, millwrights, or maintenance technicians fitting rotating assemblies on industrial and commercial equipment.

Mill stock key stock is used wherever a keyed shaft-to-hub connection is required in power-transmission assemblies. Common applications include pumps, blowers, conveyors, gear reducers, and HVAC fan assemblies. The 12-inch bar length allows the installer to cut multiple shorter keys from a single piece, reducing waste. The square 0.5 x 0.5 inch cross-section suits standard keyway cuts on shafts and bores in that nominal size range. This stock is appropriate for light-to-medium duty torque loads in both residential mechanical systems and light commercial machinery.

Key Features

• Low-carbon steel construction to ASTM A108 material specification
• Rockwell B80-90 hardness for reliable shear resistance in torque-transfer applications
• Square cross-section: 0.5 inches wide by 0.5 inches high
• 12-inch bar length allows field-cutting to required key length
• Plain finish — no coating to interfere with keyway fit or dimensional tolerance
• Pack of 4 pieces for stocking multiple repairs from a single order

Compatibility

Designed as an OEM-style replacement or maintenance stock for any power-transmission application requiring a 0.5 x 0.5 inch square key in a standard keyway-cut shaft or hub.

Installation Notes

Installation is performed by qualified machinists or maintenance technicians. De-energize and lock out the drive unit before removing or installing any key stock. Cut the key to final length using a metal-cutting saw or grinder, deburr all edges, and verify the key seats fully in both shaft and hub keyways before reassembling the retaining hardware. Do not force an oversized key into a keyway — verify dimensional fit against the shaft and bore specifications before installation.