Starrett 54140 O1 Tool Steel Flat Stock 7/16x1-1/4x18 in

Product Description

The STARRETT 54140 is an O1 oil-hardening tool steel flat stock bar intended for tool and die work, jig and fixture fabrication, punches, dies, and precision machined components. Manufactured to AISI Type O1 specifications, this flat stock measures 7/16 inches thick, 1-1/4 inches wide, and 18 inches long. Thickness tolerance is held to plus or minus 0.001 inches, making it suitable for applications where close dimensional control is required before and after heat treatment. At 2.78 pounds per piece, it is a manageable single-bar length for bench work or small-shop machining operations. Tool and die makers, machinists, and maintenance shops use this stock as a starting point for custom tooling.

O1 tool steel flat stock is commonly used in job shops, toolrooms, and maintenance departments for fabricating custom tools, blades, guides, and wear components. This bar is suited for applications requiring a steel that responds well to oil quench hardening, holds a keen edge after heat treat, and machines readily in the annealed state. The 18-inch length accommodates a wide range of blank sizes without excessive material waste.

Key Features

• AISI Type O1 oil-hardening tool steel for reliable heat treatment response
• Thickness tolerance of plus or minus 0.001 inches for consistent stock removal calculations
• Width tolerance of 0.000 to minus 0.005 inches for predictable fit in tool holders and fixtures
• Length tolerance of plus 0.250 inches, negative 0 inches, ensuring full nominal length is always met
• Edge squareness held to 0.003 inches per inch across all edges
• Single-piece packaging suitable for low-volume toolroom and job shop use

Compatibility

Designed as a general-purpose O1 tool steel flat bar for toolroom, die shop, and maintenance machining applications where AISI Type O1 oil-hardening steel is specified.

Installation Notes

Machining and grinding of O1 tool steel flat stock should be performed by qualified machinists or tool and die makers familiar with tool steel handling. Heat treatment, including hardening and tempering, requires controlled atmosphere or appropriate quench media and should follow the material supplier's recommended thermal cycle to achieve the desired hardness. Always use appropriate personal protective equipment when cutting, grinding, or heat treating tool steel. Secure the workpiece properly in a vise or fixture before any machining operation to prevent movement and injury.