Starrett 56988 O1 Tool Steel Flat Stock 5/16x1/2x18 in

Product Description

The STARRETT 56988 is a precision-ground O1 oil-hardening tool steel flat bar stock intended for toolmakers, machinists, and die makers who require close-tolerance raw material for cutting tools, punches, dies, and gauges. Manufactured to AISI Type O1 specification, this flat stock measures 5/16 inches thick, 1/2 inches wide, and 18 inches long. Thickness and width tolerances are held to +0.0100 to 0.0150 inches, and length tolerance is +0.2500 inches. Edge squareness is maintained at 0.003 inches per inch across all edges, making this stock ready for layout and machining operations with minimal prep work.

O1 tool steel flat stock in this size range is commonly used in job shops, toolrooms, and maintenance machining environments. Typical applications include fabricating small punches, form tools, scribers, wear plates, and custom gauging components. The 18-inch length provides enough material to yield multiple smaller blanks from a single piece. This stock is supplied in the annealed condition, which allows it to be machined and then hardened by oil quenching to achieve the desired final hardness for the finished tool or component.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable heat treatment response
• 5/16 inches thick x 1/2 inches wide x 18 inches long
• Thickness and width tolerance: +0.0100 to 0.0150 inches
• Length tolerance: +0.2500 inches
• Edge squareness: 0.003 inches per inch on all edges
• Supplied annealed for ease of machining prior to hardening

Compatibility

Designed as a standard O1 oil-hardening tool steel flat stock suitable for general toolroom and machining applications requiring AISI Type O1 material in a 5/16 x 1/2 x 18 inch form factor.

Installation Notes

Machining and heat treatment of O1 tool steel should be performed by qualified machinists or tool and die makers familiar with the material. When hardening, follow proper oil-quench procedures and temper immediately after quench to relieve stress and reduce brittleness. Always wear appropriate personal protective equipment when cutting, grinding, or heat treating tool steel. Ensure all cutting equipment is rated for hardened steel stock if the material is being machined after hardening.