Starrett 54139 O1 Tool Steel Flat Stock 7/16x1x18 in

Product Description

The STARRETT 54139 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, punches, gauges, and general precision machining applications. Manufactured to AISI Type O1 specification, this flat stock measures 7/16 inches thick, 1 inch wide, and 18 inches long, weighing approximately 2.23 pounds. The tight thickness tolerance of plus or minus 0.001 inches makes it well suited for applications where dimensional accuracy is critical before and after heat treatment. Machinists, tool and die makers, and metalworking professionals select O1 stock for its excellent machinability in the annealed state and its predictable response to oil-quench hardening.

This flat stock is used in job shops, tool rooms, and manufacturing facilities for fabricating cutting tools, jigs, fixtures, and wear components. It is appropriate for both one-off tooling projects and small production runs where precise stock dimensions reduce setup and material removal time. The 18-inch length provides a practical working blank for a wide range of tooling geometries. Stock is supplied in the annealed condition and is ready for machining prior to heat treat.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable hardening response
• Thickness tolerance of plus or minus 0.001 inches for tight dimensional control
• Width tolerance of 0.000 to 0.005 inches under nominal
• Length tolerance of plus 0.250 inches, minus 0 inches
• Edge squareness: all edges within 0.003 inches per inch
• Supplied in annealed condition, ready for machining

Compatibility

Designed as a standard O1 tool steel flat stock blank for use in tool rooms, die shops, and precision machining environments where AISI O1 oil-hardening material is specified.

Installation Notes

Machining of O1 tool steel flat stock should be performed with appropriate cutting tools rated for tool steel in the annealed condition. Operators should follow established heat treatment procedures for O1 steel, including proper preheat, hardening, and oil-quench steps, as specified by the material supplier or applicable shop standards. Personal protective equipment is required when performing grinding, sawing, or heat treatment operations. Consult applicable shop safety and fire codes when using oil-quench hardening procedures.