Starrett 54190 O1 Tool Steel Flat Stock 0.75x1.5x18 in

Product Description

The STARRETT 54190 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 0.75 inches thick, 1.5 inches wide, and 18 inches long, with a finished weight of 5.74 pounds. Thickness tolerance is held to plus or minus 0.001 inches, and squareness is controlled to 0.003 inches per inch on all edges. O1 tool steel offers good machinability in the annealed state and responds well to oil-quench hardening, making it a reliable choice for custom tooling, punches, gauges, and fixture components.

This flat stock is suited for job shops, tool and die operations, and maintenance departments that need a standard-size blank for machining, grinding, or hardening to a finished tool. The 18-inch length provides enough stock for multiple short tooling blanks or a single longer component. The controlled width and thickness tolerances reduce the amount of finish grinding required before use, saving setup time on the surface grinder or milling machine. Machinists and toolmakers working on tight-tolerance fixtures or cutting tools will find this a practical starting blank.

Key Features

• AISI Type O1 oil-hardening tool steel construction for consistent heat treat response
• Thickness held to plus or minus 0.001 inches for reduced finish grinding
• Width tolerance of 0.000 to 0.005 inches under nominal
• Length tolerance of plus 0.250 inches, minus 0 inches
• Edge squareness controlled to 0.003 inches per inch on all edges
• Single-piece packaging — no multi-bar minimum required

Compatibility

Designed as a standard O1 tool steel flat stock blank suitable for general toolmaking, die making, punch fabrication, and precision fixture work where oil-hardening tool steel stock is specified.

Installation Notes

Machining and grinding of O1 tool steel should be performed with appropriate cutting fluids to control heat and preserve the annealed condition before hardening. Oil-quench hardening and tempering should be carried out by a qualified toolmaker or heat treater following established metallurgical procedures. Always wear appropriate PPE when cutting, grinding, or heat treating tool steel stock. Consult applicable shop safety standards when operating surface grinders, mills, or heat treat equipment.