Starrett 54040 O1 Tool Steel Flat Stock 5/32x6x18 in

Product Description

The STARRETT 54040 is an O1 oil-hardening tool steel flat stock blank used in toolmaking, die making, jig fabrication, and precision machining applications. Cut to 5/32 inch thick, 6 inches wide, and 18 inches long, it ships in a ready-to-use blank form that machinists and toolmakers grind, mill, or otherwise finish before hardening. The material conforms to AISI Type O1 oil-hardening specification and holds a thickness tolerance of plus or minus 0.001 inches, making it suitable for applications where dimensional consistency before heat treatment is critical.

This flat stock is used in machine shops, tool and die operations, and precision fabrication environments. Typical applications include cutting tools, form tools, punches, dies, and gauges where a medium-alloy oil-hardening steel is the specified material. The 6-inch width and 18-inch length provide enough material for most bench-scale toolmaking tasks without requiring a larger plate saw operation to rough-cut the blank down to a workable size.

Key Features

• AISI Type O1 oil-hardening tool steel — suitable for heat-treat hardening in an oil quench
• Thickness tolerance of plus or minus 0.001 inches for consistent pre-grind stock removal planning
• Width tolerance of 0.000 to minus 0.005 inches — blank arrives at or slightly under nominal 6 inches
• Length tolerance of plus 0.250 inches — blank arrives at or above nominal 18 inches
• Edge squareness held to 0.003 inches per inch on all edges
• Single-piece packaging — no minimum split required, order one piece per unit

Compatibility

Designed as a standard O1 tool steel flat stock blank for general toolmaking and die-making applications requiring AISI Type O1 oil-hardening material at 5/32 x 6 x 18 inch nominal dimensions.

Installation Notes

Machining and heat treatment of tool steel should be performed by qualified machinists or tool and die makers familiar with O1 steel properties and oil-quench hardening procedures. Always follow proper personal protective equipment and shop safety protocols when cutting, grinding, or heat-treating tool steel. Consult applicable heat-treatment specifications for O1 before hardening and tempering to avoid cracking or warping. Do not apply hardening procedures based on numeric values not verified against the material certification for this specific stock.