Starrett 54172 O1 Tool Steel Flat Stock 5/8x5/8x18 in

Product Description

The STARRETT 54172 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, and precision machining applications. Manufactured from AISI Type O1 tool steel, this flat stock measures 0.625 inches thick by 0.625 inches wide by 18 inches long and weighs approximately 1.99 pounds. Thickness and squareness tolerances are held to plus or minus 0.001 inches, with width tolerance of 0.000 to 0.005 inches and a length tolerance of plus 0.250 inches. Edge squareness is maintained at 0.003 inches per inch across all edges. Machinists, tool-and-die makers, and metalworking fabricators use this material for producing punches, dies, gauges, and cutting tools that will be hardened through an oil-quench heat treatment process.

This flat stock is suited for job shops, tool rooms, and maintenance departments working in both light industrial and heavy manufacturing environments. The 18-inch length provides enough material for a range of small tooling blanks or multiple short workpieces. Because O1 tool steel machines in the annealed state and responds predictably to oil-hardening heat treatment, it is a common choice when dimensional accuracy before and after hardening is critical. This bar is sold individually and is appropriate for low-volume prototype work as well as production tooling replacement.

Key Features

• AISI Type O1 oil-hardening tool steel construction for predictable heat-treat response
• Thickness and squareness tolerance of plus or minus 0.001 inches for precision fitment
• Width tolerance of 0.000 to 0.005 inches, length tolerance of plus 0.250 inches
• Edge squareness held to 0.003 inches per inch on all edges
• 0.625 inches x 0.625 inches cross-section in an 18-inch bar length
• Sold as a single piece with no minimum order beyond one unit

Compatibility

Designed as a standard AISI Type O1 oil-hardening flat stock suitable for general toolmaking and die-making applications requiring a square-section tool steel blank in the 5/8-inch thickness and width class.

Installation Notes

O1 tool steel flat stock is processed by machinists and tool-and-die makers using conventional milling, drilling, and grinding equipment in the annealed condition. Heat treatment to harden the material requires oil quenching and should be performed by qualified heat-treat personnel following established metallurgical procedures. Ensure all machining and finishing operations are complete before hardening, as post-hardening dimensional changes may occur. Follow applicable shop safety standards when handling and storing bare steel stock.