Starrett 54391 O1 Tool Steel Flat Stock 5/16 X 5/16 X 36 in

Product Description

The STARRETT 54391 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, jig fabrication, and precision machining applications. Manufactured to AISI Type O1 specifications, this flat stock measures 5/16 inches thick, 5/16 inches wide, and 36 inches long, with a weight of 1 pound. Thickness tolerance is held to plus or minus 0.001 inches, making it suitable for applications that demand close dimensional control. O1 tool steel is known for its consistent hardening response in oil-quench heat treatment, good wear resistance, and machinability in the annealed state. Machinists, tool and die makers, and precision fabricators work with this material regularly.

This flat stock is used in the production of punches, dies, gauges, cutting tools, and machine components where a tough, hardenable steel with tight dimensional tolerances is required. It is appropriate for both small job shop operations and production toolrooms. The 36-inch length allows for single-piece blanks or multiple shorter sections to be cut from one bar. Typical users include tool and die makers, mold makers, and precision machinists working in industrial or trade shop environments.

Key Features

• AISI Type O1 oil-hardening tool steel for consistent, controlled heat treatment response
• Thickness held to plus or minus 0.001 inches for precision fitment
• Width tolerance of 0.000 to minus 0.005 inches for controlled stock removal
• Length tolerance of plus 0.015 inches for full usable length
• Edge squareness held to 0.003 inches per inch across all edges
• 36-inch length provides flexibility for single or multiple workpiece blanks

Compatibility

Designed as a standard AISI Type O1 oil-hardening tool steel flat stock suitable for toolmaking, die making, and general precision fabrication applications requiring a hardenable tool steel in annealed flat bar form.

Installation Notes

Cutting and machining should be performed with appropriate tooling rated for tool steel in the annealed condition. Heat treatment to harden this material requires oil quenching per standard O1 procedures and should be performed by qualified personnel using calibrated furnace equipment. Always wear appropriate PPE when cutting, grinding, or heat treating tool steel. Follow applicable shop safety codes and employer procedures when handling sharp-edged stock material.