Starrett 56992 O1 Tool Steel Flat Stock 5/16x1-1/2x18 in

Product Description

The STARRETT 56992 is an O1 oil-hardening tool steel flat stock bar measuring 5/16 inches thick, 1-1/2 inches wide, and 18 inches long. Manufactured to AISI Type O1 specifications, this flat stock is a high-carbon, high-precision ground steel bar used in toolmaking, die work, jig fabrication, and precision machining applications. It ships in an annealed condition, ready for machining, then hardens in oil quench. Thickness and width tolerances are held to +0.0100 to +0.0150 inches. Edge squareness is held to 0.003 inches per inch on all edges, making it suitable for direct layout and close-tolerance work without additional grinding on the reference faces.

This flat stock is used in machine shops, tool-and-die rooms, and maintenance departments where consistent material properties and tight dimensional tolerances are required. Typical applications include making blanking dies, punches, bushings, gauges, and cutting tools. It is cut to 18 inches, which allows multiple blanks to be laid out and cut from a single piece. The weight of approximately 2.39 pounds makes it easy to handle on a surface plate or bandsaw setup. Machinists, tool-and-die makers, and maintenance technicians are the primary users of this material.

Key Features

• AISI Type O1 oil-hardening tool steel — consistent hardening response in oil quench
• Thickness and width held to +0.0100 to +0.0150 inches for close-tolerance blanks
• Edge squareness: 0.003 inches per inch on all edges
• Length tolerance: +0.2500 inches
• Flat bar profile: 5/16 inches thick x 1-1/2 inches wide x 18 inches long
• Ships annealed and ready for machining prior to heat treatment

Compatibility

Designed as a general-purpose O1 oil-hardening tool steel flat bar for use in tool-and-die, punch-and-die, gauge, and fixture fabrication applications wherever AISI O1 material specification is required.

Installation Notes

O1 tool steel flat stock is machined in the annealed condition using standard metalworking equipment before heat treatment. Oil hardening should be performed by a qualified heat treater following accepted AISI O1 procedures for austenitizing temperature, quench media, and tempering cycles. Always wear appropriate personal protective equipment when cutting, grinding, or handling steel bar stock. Verify final dimensions after any grinding or surface preparation step before beginning die or tool layout.