Starrett 56979 O1 Tool Steel Flat Stock 0.25x2.5x18 in

Product Description

The STARRETT 56979 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, and precision machining applications. Manufactured to AISI Type O1 specifications, this flat stock measures 0.25 inches thick, 2.5 inches wide, and 18 inches long, with a weight of 3.19 pounds. Thickness and width tolerances are held to +0.0100 to +0.0150 inches, and length tolerance is +0.25 inches. Edge squareness is maintained at 0.003 inches per inch across all edges. O1 tool steel is valued for its ability to achieve high hardness after oil quench and for its dimensional stability through the hardening process.

This flat stock is suited for fabricating punches, dies, gauges, jigs, fixtures, and cutting tools in machine shops, tool rooms, and industrial maintenance environments. The 18-inch length provides usable stock for multiple short blanks or a single longer workpiece. The pre-ground flat profile reduces setup time compared to raw bar stock. Machinists and toolmakers working in annealed condition will find this stock machines cleanly before heat treatment.

Key Features

• AISI Type O1 oil-hardening tool steel for reliable heat treat response
• Thickness and width tolerances of +0.0100 to +0.0150 inches for close-tolerance work
• Edge squareness held to 0.003 inches per inch on all edges
• Length tolerance of +0.25 inches provides full usable material
• Pre-ground flat surfaces reduce prep time before machining or layout
• Single-piece package quantity suitable for low-volume and one-off toolmaking jobs

Compatibility

Designed as a general-purpose O1 oil-hardening tool steel flat stock for use in tool rooms, die shops, and precision machining applications requiring AISI Type O1 material specification.

Installation Notes

Cutting, grinding, and machining of tool steel flat stock is typically performed by machinists or toolmakers using appropriate metalworking equipment. Always follow shop safety protocols when cutting or grinding tool steel, including eye protection and proper workholding. Heat treatment should be performed by qualified personnel following established procedures for AISI O1 tool steel, including proper preheat, austenitizing, and oil quench steps. Consult applicable shop standards and material data sheets before hardening.