Starrett 54375 O1 Tool Steel Flat Stock 0.25x5.5x36 in

Product Description

The STARRETT 54375 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 specifications, this flat stock measures 0.25 inches thick, 5.5 inches wide, and 36 inches long, with a weight of 14.03 pounds. Thickness and squareness tolerances are held to plus or minus 0.001 inches, making it suitable for applications where dimensional consistency is critical before and after heat treatment. O1 tool steel offers good machinability in the annealed state and responds well to oil-quench hardening, retaining a sharp edge after heat treat.

This flat stock is a standard choice for fabricating punches, dies, gauges, cutting tools, blanking tools, and machine components that require hardening after rough machining. It is commonly used in job shops, tool and die shops, and precision manufacturing environments. The 36-inch length provides enough stock for multiple parts to be cut from a single bar, reducing material waste on typical shop projects.

Key Features

• AISI Type O1 oil-hardening tool steel — machines cleanly in annealed condition and hardens via oil quench
• Thickness tolerance: plus or minus 0.001 inches for consistent stock removal and fit-up
• Width tolerance: 0.000 to minus 0.005 inches
• Length tolerance: plus 0.015 inches
• Squareness: edge squareness held to 0.003 inches per inch on all edges
• Full 36-inch bar length suitable for cutting multiple workpieces

Compatibility

Designed as a standard O1 oil-hardening tool steel flat stock for general toolmaking and die-making applications where AISI Type O1 material specification is required.

Installation Notes

Cutting, grinding, and machining of tool steel flat stock should be performed by qualified machinists or tool and die makers using appropriate cutting fluids and tooling rated for hardened or semi-hardened steels. Handle bar stock with care to avoid surface nicks or damage that can create stress risers during heat treatment. Heat treatment including hardening and tempering should follow AISI O1 guidelines and be performed in a controlled environment; consult a qualified heat treater for critical applications. Always wear appropriate PPE when cutting or grinding tool steel.