Starrett 54370 O1 Tool Steel Flat Stock 1/4x3x36 in

Product Description

The STARRETT 54370 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, jig fabrication, and precision machining applications. Manufactured to AISI Type O1 specification, this flat stock measures 0.25 inches thick, 3 inches wide, and 36 inches long, with a weight of 7.65 pounds per bar. Thickness tolerance is held to plus or minus 0.001 inches, making it suitable for applications where dimensional accuracy matters before and after heat treatment. O1 tool steel is known for its excellent machinability in the annealed state and its ability to hold a sharp edge after oil quench hardening.

This flat stock is used by machinists, toolmakers, and die makers in job shop, production, and maintenance environments. Common applications include punches, dies, gauges, cutting tools, and wear plates. The 36-inch bar length allows for multiple blanks to be cut from a single piece, reducing material waste in short-run tooling operations. Both residential shops and industrial toolrooms stock O1 flat stock as a general-purpose tool steel for low-to-medium production tooling where dimensional stability after hardening is required.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable heat treat response
• Thickness tolerance of plus or minus 0.001 inches for precision fit before machining
• Length tolerance of plus 0.015 inches, zero minus, ensuring full nominal length
• Width tolerance of 0.000 to minus 0.005 inches for consistent stock removal planning
• Edge squareness held to 0.003 inches per inch across all edges
• 36-inch bar length supports multi-blank cutting from a single piece

Compatibility

Designed as a standard AISI O1 oil-hardening flat stock suitable for general toolmaking, die, and fixture fabrication where oil-quench hardenable tool steel in flat bar form is specified.

Installation Notes

Cutting and machining of tool steel flat stock should be performed with appropriate metalworking equipment by qualified machinists or toolmakers. O1 steel should be annealed before machining if received in a hardened condition, and oil-quench heat treatment should follow established metallurgical procedures for AISI O1. Always use proper eye protection and cutting fluids when sawing or milling tool steel bar stock. Consult applicable shop safety and OSHA standards for metalworking operations.