Starrett 57001 O1 Tool Steel Flat Stock 3/8x1x18 in

Product Description

The STARRETT 57001 is an O1 oil-hardening tool steel flat stock bar intended for toolmakers, machinists, and die makers who need precise, ready-to-machine steel in a known alloy. The bar measures 0.375 inches thick, 1 inch wide, and 18 inches long, with a weight of 1.91 pounds. O1 tool steel is an oil-hardening grade known for its dimensional stability during heat treatment and good wear resistance after hardening, making it a reliable choice for punches, dies, gauges, and general tooling applications. Thickness and width tolerances are held to +0.0100 to 0.0150 inches, and edge squareness is held to 0.003 inches per inch.

This flat stock is suited for job shops, tool and die operations, and maintenance departments requiring short-run tooling material. The 18-inch length provides a practical starting blank for cutting, milling, grinding, or turning down to final dimensions. The material ships in its annealed, pre-hardened state, which allows conventional machining before oil quenching to final hardness. It is appropriate for both prototype and production tooling work in shop environments.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable hardening response
• Thickness: 0.375 inches with +0.0100 to 0.0150 inch tolerance
• Width: 1 inch with +0.0100 to 0.0150 inch tolerance
• Length: 18 inches with +0.2500 inch tolerance
• Edge squareness held to 0.003 inches per inch on all edges
• Weight: 1.91 pounds per piece

Compatibility

Designed as a general-purpose O1 tool steel flat bar suitable for machined tooling, dies, punches, gauges, and similar shop-fabricated components requiring oil-hardening steel stock.

Installation Notes

Material arrives in the annealed condition and should be machined using standard high-speed steel or carbide tooling appropriate for tool steel. Leave grinding or finish stock allowance before heat treatment, as oil quenching will produce minor distortion. Hardening should be performed by a qualified heat treater familiar with O1 alloy procedures. Always allow the bar to reach ambient temperature before precision layout or measurement.