Starrett 54401 O1 Tool Steel Flat Stock 5/16x4x36 in

Product Description

The STARRETT 54401 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, and precision machining applications. It is manufactured from AISI Type O1 oil-hardening tool steel and measures 5/16 inches thick, 4 inches wide, and 36 inches long. The bar holds a thickness tolerance of plus or minus 0.001 inches and a squareness of 0.003 inches per inch on all edges, making it suitable for applications requiring close dimensional control. Machinists, tool-and-die makers, and metalworking shops use this stock to fabricate punches, dies, gauges, and other precision tooling components that will be hardened after machining.

This flat stock is intended for use in job shops, toolrooms, and manufacturing facilities where O1 tool steel is specified. O1 is widely chosen for its good machinability in the annealed condition and its ability to achieve high hardness after oil quenching. The 36-inch length provides sufficient stock for most standard tooling blanks without requiring a saw cut before layout. The 4-inch width accommodates a broad range of die plate and flat tool applications.

Key Features

• AISI Type O1 oil-hardening tool steel — machinable in annealed state, hardens by oil quench
• Thickness tolerance of plus or minus 0.001 inches for precise stock allowance planning
• Width tolerance of minus 0.000 to minus 0.005 inches
• Length tolerance of plus 0.015 inches, minus 0 inches
• Squareness held to 0.003 inches per inch on all edges
• Single-piece packaging with no minimum order above one piece

Compatibility

Designed as a standard O1 oil-hardening tool steel flat bar for use in general toolroom and die-making applications wherever AISI Type O1 material is specified.

Installation Notes

O1 tool steel flat stock is worked by machinists and tool-and-die makers using conventional milling, grinding, and EDM equipment in the annealed condition before heat treatment. Always allow adequate stock for grinding to final dimension after hardening and tempering, as distortion can occur during the oil-quench process. Heat treatment should be performed by qualified personnel following established time-temperature guidelines for O1 tool steel. Secure workpieces properly during machining to avoid deflection given the length and width of this bar.