Starrett 54113 O1 Tool Steel Flat Stock 5/16x5x18 in

Product Description

The STARRETT 54113 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, and precision machining applications. Manufactured to AISI Type O1 specification, this flat stock measures 5/16 inches thick, 5 inches wide, and 18 inches long, with a weight of 7.97 pounds. Thickness and squareness tolerances are held to plus or minus 0.001 inches, making this material suitable for applications where dimensional consistency is critical before and after heat treatment. Machinists, tool-and-die makers, and fabricators work with this stock to produce punches, dies, gauges, and other tooling components that require hardening.

O1 tool steel flat stock is used in job shops, maintenance departments, and manufacturing environments where custom tooling must be cut, machined, and then oil-hardened to achieve the required surface hardness and wear resistance. This bar is appropriate for low-to-medium production tooling where tight dimensional tolerances are needed in the annealed state prior to heat treat. The 18-inch length provides a workable blank size for a wide range of tooling profiles, and the 5-inch width accommodates larger die plates and fixture components without requiring additional material joining.

Key Features

• AISI Type O1 oil-hardening tool steel material specification
• Thickness and squareness tolerance of plus or minus 0.001 inches for precision fitment
• Width tolerance of 0.000 to 0.005 inches under nominal
• Length tolerance of plus 0.250 inches, minus 0
• Edge squareness held to 0.003 inches per inch across all edges
• Ships as a single 5/16 x 5 x 18 inch flat bar at 7.97 pounds

Compatibility

Designed as a general-purpose O1 oil-hardening tool steel flat stock suitable for use in standard toolmaking, die, and fixture fabrication applications requiring AISI Type O1 material.

Installation Notes

O1 tool steel flat stock is machined in the annealed state using conventional milling, grinding, and drilling equipment. Oil hardening must be performed by a qualified heat treater following established AISI O1 heat treatment procedures. Handle with care to avoid surface nicks or edge damage that could affect tolerance-critical finished parts. Always verify final dimensions after heat treatment, as distortion may occur during the hardening cycle.