Starrett 56957 O1 Tool Steel Flat Stock 3/16 X 18 in

Product Description

The STARRETT 56957 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, and precision machining applications. It measures 3/16 inches thick by 3/16 inches wide by 18 inches long and is manufactured from AISI Type O1 oil-hardening tool steel. The thickness tolerance runs from +0.010 to +0.015 inches, with matching width tolerance in the same range. Length tolerance is +0.25 inches. Squareness is held to 0.003 inches per inch on all edges. This material ships in the annealed condition and is intended for machining to final shape before heat treatment. Machinists, toolmakers, and die makers are the primary installers and end users.

O1 flat stock at this cross-section is well suited for small punches, form tools, blades, gauges, and similar precision tooling components. The 3/16-inch square profile makes it practical for applications where minimal stock removal is needed before final shaping. It is commonly used in job shops, tool rooms, and maintenance environments where small quantities of precision ground flat stock are required for one-off or short-run tooling.

Key Features

• AISI Type O1 oil-hardening tool steel for reliable hardness response in standard oil-quench heat treatment
• 3/16 inches thick by 3/16 inches wide square profile for minimal finish machining
• 18 inches long with +0.25 inch length tolerance
• Thickness and width tolerance of +0.010 to +0.015 inches for close dimensional control
• Squareness held to 0.003 inches per inch on all edges
• Ships in annealed condition, ready for machining prior to heat treat

Compatibility

Designed as a standard O1 oil-hardening flat stock for use in tool and die fabrication, gauge making, and general precision machining where AISI Type O1 tool steel is specified.

Installation Notes

Cutting and machining should be performed while the stock is in the annealed condition before any heat treatment is applied. Use appropriate cutting fluids and tooling rated for tool steel when sawing or milling to length. Heat treatment including hardening and tempering should be performed by qualified personnel following established metallurgical procedures for AISI O1 tool steel. Handle cut edges carefully, as sharp burrs are expected after machining.