Starrett 53979 O1 Tool Steel Flat Stock 3/32x3/4x18 in

Product Description

The STARRETT 53979 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 3/32 inches thick, 3/4 inches wide, and 18 inches long, with a thickness tolerance of plus or minus 0.001 inches. O1 tool steel is valued for its consistent hardening response in oil-quench heat treatment and its ability to hold a sharp, durable edge after hardening. This bar is supplied in the annealed condition, ready for machining and subsequent heat treatment by tool and die makers, machinists, and metalworking professionals.

This flat stock is suited for fabricating punches, dies, cutting tools, gauges, and other precision tooling components. The 18-inch length provides workable stock for a range of tool blanks and shop-made fixtures. The close thickness tolerance of plus or minus 0.001 inches reduces the amount of finish grinding required before use, making it a practical choice for both production toolmaking and one-off tool fabrication in machine shops and tool rooms.

Key Features

• AISI Type O1 oil-hardening tool steel for reliable, repeatable heat treatment response
• Thickness tolerance of plus or minus 0.001 inches for precision stock removal planning
• Width tolerance of 0.000 to minus 0.005 inches for consistent width control
• Length tolerance of plus 0.250 inches ensures full usable length
• Edge squareness of 0.003 inches per inch across all edges
• Supplied in annealed condition, ready for machining prior to hardening

Compatibility

Designed as a standard AISI O1 oil-hardening tool steel flat bar suitable for general toolmaking, die making, and precision machining applications requiring close-tolerance flat stock.

Installation Notes

Machining and heat treatment of O1 tool steel should be performed by qualified machinists or tool and die makers familiar with tool steel handling procedures. Always use appropriate cutting fluids during machining to preserve edge life and dimensional accuracy. Heat treatment, including hardening and tempering, must follow established thermal cycling procedures for O1 tool steel and should be performed with calibrated equipment. Handle annealed stock carefully to avoid surface nicks or burrs that may affect finished tool dimensions.