Starrett 56971 O1 Tool Steel Flat Stock 1/4 X 1/4 X 18 in

Product Description

The STARRETT 56971 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, jig building, die work, and precision machining applications. Manufactured to AISI Type O1 specifications, this flat stock measures 0.25 inches thick by 0.25 inches wide by 18 inches long and weighs 0.32 pounds. Thickness and width tolerances are held to +0.0100 to +0.0150 inches, while length tolerance is +0.2500 inches. Edge squareness is held to 0.003 inches per inch across all edges. O1 tool steel is a widely used oil-hardening grade known for its dimensional stability during heat treatment, making it a reliable choice for precision tooling blanks and wear components.

This flat stock is suited for machine shops, tool and die operations, and industrial maintenance environments where close-tolerance stock is required before or after heat treatment. The 18-inch length provides useful stock for fabricating punches, blades, gauges, and similar precision components. It is intended for professional machinists, tool and die makers, and skilled tradespeople working in metalworking and manufacturing settings.

Key Features

• AISI Type O1 oil-hardening tool steel construction
• Thickness and width held to +0.0100 to +0.0150 inches tolerance
• Edge squareness: 0.003 inches per inch on all edges
• Length tolerance of +0.2500 inches on 18-inch bar
• Compact 0.25 inch by 0.25 inch cross-section for small tooling blanks
• Weighs 0.32 pounds — lightweight for single-piece handling and storage

Compatibility

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

Installation Notes

Cutting and grinding of tool steel flat stock should be performed with appropriate metalworking equipment and eye and hand protection. O1 tool steel is typically hardened by heating to the manufacturer-recommended austenitizing range and quenching in oil — follow your shop's established heat treatment procedures and applicable safety protocols. Allow bars to fully cool before handling after heat treatment. Machining operations before hardening are recommended for best dimensional accuracy.