Starrett 54240 O1 Tool Steel Flat Stock 1.5x1.5x18 in

Product Description

The STARRETT 54240 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, and precision machining applications. Made from AISI Type O1 tool steel, it measures 1-1/2 inches thick by 1-1/2 inches wide by 18 inches long and weighs approximately 11.48 pounds. The O1 grade offers excellent machinability in the annealed state and responds well to oil-quench hardening, making it a reliable choice for punches, dies, gauges, and similar tooling components. Thickness tolerance is held to plus or minus 0.001 inches, and edge squareness is maintained at 0.003 inches per inch across all edges.

This flat stock is suited for job shops, tool-and-die operations, and maintenance machining environments where close-tolerance blanks are needed without extensive pre-machining. The 18-inch length provides a practical starting blank for a wide range of tooling projects. Machinists and tool-and-die makers typically saw, mill, or grind this stock to final dimensions before hardening. The oil-hardening designation means this grade is quenched in oil rather than water, which reduces the risk of distortion and cracking during heat treatment compared to water-hardening grades.

Key Features

• AISI Type O1 oil-hardening tool steel for consistent hardenability and dimensional stability after quench
• Thickness tolerance of plus or minus 0.001 inches for precise blank sizing
• Width tolerance of 0.000 to minus 0.005 inches
• Length tolerance of plus 0.250 inches
• Edge squareness held to 0.003 inches per inch on all edges
• Ready-to-machine annealed condition allows standard HSS or carbide tooling

Compatibility

Designed as a standard AISI Type O1 oil-hardening tool steel flat stock suitable for general toolmaking, die making, and precision fixture fabrication where O1 grade material is specified.

Installation Notes

Machining and heat treatment of tool steel should be performed by qualified machinists or tool-and-die professionals familiar with O1 grade handling. Always follow proper heat treatment procedures per the material specification, including pre-heat, austenitizing, and oil-quench sequences appropriate for O1 steel. Use appropriate personal protective equipment when cutting, grinding, or heat treating this material. Consult applicable shop safety standards and material data sheets before processing.