Starrett 54445 O1 Tool Steel Flat Stock 1/2x3x36

Product Description

The STARRETT 54445 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, jig fabrication, and precision machining applications. Manufactured to AISI Type O1 specification, this flat stock measures 0.5 inches thick, 3 inches wide, and 36 inches long, and weighs approximately 15.3 pounds. O1 tool steel offers excellent machinability in the annealed state and develops high hardness when oil-quenched, making it a go-to material for cutting tools, punches, gauges, and wear components. Thickness tolerance is held to plus or minus 0.001 inches, ensuring consistent stock removal and predictable heat-treat results across the bar.

This flat stock is suited for machine shops, tool and die shops, and maintenance departments where precision-ground or precision-tolerance steel bar is required. It is commonly used to fabricate custom tooling, blanks for stamps and dies, fixtures, straight edges, and similar components that require tight dimensional control before and after hardening. The 36-inch length provides enough stock for multiple parts from a single piece, reducing material waste in low-to-medium production toolroom environments.

Key Features

• AISI Type O1 oil-hardening tool steel for excellent machinability and high post-quench hardness
• Thickness tolerance of plus or minus 0.001 inches for predictable finish and heat-treat performance
• Width tolerance of 0.000 to minus 0.005 inches for controlled fit in close-tolerance applications
• Length tolerance of plus 0.015 inches with no negative allowance
• Edge squareness held to 0.003 inches per inch across all edges
• 36-inch length provides usable stock for multiple toolroom blanks from one piece

Compatibility

Designed as a general-purpose O1 oil-hardening tool steel flat stock for use in toolroom, die making, and precision fabrication applications where AISI Type O1 material specification is required.

Installation Notes

Cutting and machining of tool steel flat stock should be performed by qualified machinists using appropriate coolant and carbide or high-speed steel tooling. Before hardening operations, confirm all machining, grinding, and finishing are complete, as post-harden stock removal is significantly more difficult. Oil-quenching should follow the material manufacturer's recommended procedure for AISI O1 to achieve target hardness and minimize distortion. Always wear appropriate PPE when handling, cutting, or heat-treating tool steel.