Starrett 54428 O1 Tool Steel Flat Stock 7/16x3/4x36in

Product Description

The STARRETT 54428 is an O1 oil-hardening tool steel flat stock bar sized at 7/16 inches thick, 3/4 inches wide, and 36 inches long. Manufactured to AISI Type O1 specifications, this flat stock is used as raw material for fabricating cutting tools, punches, dies, gauges, and precision tooling components. O1 tool steel offers good machinability in the annealed state and achieves high hardness after oil-quench heat treatment. The 54428 ships in a soft, machinable condition, allowing the fabricator to machine to final shape before hardening. Weight is 3.35 pounds per bar.

O1 flat stock of this profile is commonly used in toolroom, die shop, and general metalworking environments where close-tolerance blanks are required. Typical applications include blanking dies, forming tools, shear blades, and precision gauging fixtures. The 36-inch length provides a standard stock length suitable for cutting multiple shorter blanks on a bandsaw or cold saw. Machinists and tool-and-die makers are the primary users of this material.

Key Features

• AISI Type O1 oil-hardening tool steel — good machinability before heat treat, high hardness after quench
• Thickness tolerance of plus or minus 0.001 inches for consistent stock removal planning
• Width tolerance of 0.000 to minus 0.005 inches for tight dimensional control
• Length tolerance of plus 0.015 inches
• Squareness: edge all 0.003 inches per inch
• Supplied in annealed condition — ready for machining prior to hardening

Compatibility

Designed as a standard AISI O1 oil-hardening tool steel flat bar suitable for general toolroom and die-making applications requiring a 7/16 inch by 3/4 inch cross-section profile.

Installation Notes

This material is installed by machinists and tool-and-die makers using standard metalworking equipment including milling machines, surface grinders, and bandsaws. Heat treatment should be performed by qualified personnel following established procedures for AISI O1 tool steel, including proper preheat, austenitizing, and oil-quench cycles. Always allow material to reach ambient temperature before precision grinding after hardening. Follow applicable shop safety practices when cutting or grinding tool steel.