Starrett 54519 O1 Tool Steel Flat Stock 1-1/4x1-1/4x36in

Product Description

The STARRETT 54519 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, jig fabrication, and precision machining applications. Manufactured to AISI Type O1 specifications, this flat stock measures 1-1/4 inches thick, 1-1/4 inches wide, and 36 inches long, with a weight of 15.94 pounds. Thickness and squareness tolerances are held to plus or minus 0.001 inches, making this bar suitable for close-tolerance work where dimensional consistency is required before and after heat treatment. Machinists, tool and die makers, and industrial maintenance professionals work with this material in job shop and production environments.

O1 tool steel flat stock is a standard choice for fabricating punches, dies, gauges, jigs, fixtures, and cutting tools. It machines well in the annealed condition and responds predictably to oil-hardening heat treatment, achieving high surface hardness while maintaining core toughness. This 36-inch length provides enough material for most toolroom blanks and can be cut to final length with standard shop equipment. The square cross-section profile suits applications where both faces and edges need to be ground or used as reference surfaces.

Key Features

• AISI Type O1 oil-hardening tool steel — machines well annealed, hardens predictably in oil quench
• Thickness and squareness tolerance: plus or minus 0.001 inches for close-tolerance toolroom use
• Width tolerance: 0.000 to minus 0.005 inches
• Length tolerance: plus 0.015 inches
• Edge squareness: all edges held to 0.003 inches per inch
• Weighs 15.94 pounds — full 36-inch bar ready to cut to blank length

Compatibility

Designed as a standard AISI Type O1 oil-hardening tool steel flat stock suitable for general toolroom, die-making, and precision machining applications requiring consistent pre-hardened dimensional tolerances.

Installation Notes

Cutting, grinding, and heat treatment of tool steel should be performed by qualified machinists or tool and die makers using appropriate shop equipment and personal protective equipment. Follow established shop procedures and the material supplier's heat treatment guidelines when hardening O1 tool steel, including proper preheat, austenitizing temperature, and oil quench technique. Grinding after hardening requires adequate coolant to prevent surface tempering. Deburr all cut edges before handling.