Starrett 54400 O1 Tool Steel Flat Stock 5/16x3-1/2x36 in

Product Description

The STARRETT 54400 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, jig fabrication, and precision machining applications. Manufactured to AISI Type O1 specification, this flat stock measures 5/16 inch thick, 3-1/2 inches wide, and 36 inches long, and weighs 11.16 pounds. O1 tool steel is a cold-work oil-hardening alloy known for its dimensional stability during heat treatment and its ability to hold a sharp edge after hardening. Thickness tolerance is held to plus or minus 0.001 inch, making this stock suitable for close-tolerance tooling work where pre-ground stock dimensions are critical to layout and machining.

This flat stock is used in machine shops, tool and die shops, and precision fabrication environments. Typical applications include blanks for punches, dies, gauges, cutting tools, and fixtures. The 36-inch length provides adequate material for most shop floor cutting operations. Width tolerance runs from 0.000 to minus 0.005 inch, and length tolerance is held to plus 0.015 inch. Edge squareness is maintained at 0.003 inch per inch across all edges. Machinists and toolmakers typically cut this stock to rough size before heat treating and finishing to final dimension.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable hardening in oil quench
• Thickness tolerance of plus or minus 0.001 inch for close-tolerance tooling blanks
• Edge squareness held to 0.003 inch per inch on all edges
• 36-inch length supports common shop floor rough-cutting operations
• Width tolerance 0.000 to minus 0.005 inch for consistent stock removal planning
• Length tolerance plus 0.015 inch ensures full nominal length is always met

Compatibility

Designed as a general-purpose O1 tool steel flat stock blank suitable for toolmaking, die making, gauge fabrication, and fixture construction in machine shop and tool and die environments.

Installation Notes

O1 tool steel flat stock is machined, ground, and heat-treated by qualified toolmakers or machinists. Rough-machine to near-net shape before oil hardening to minimize post-heat-treat distortion. Always use appropriate personal protective equipment and follow shop safety protocols when cutting, grinding, or heat-treating tool steel. Heat treatment parameters should follow AISI O1 guidelines and be performed by personnel experienced with tool steel metallurgy.