Starrett 56517 O1 Tool Steel Flat Stock 1/4x1/4x36 in

Product Description

The STARRETT 56517 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, fixture fabrication, and precision machining applications. Manufactured to AISI Type O1 material specification, this flat stock measures 0.25 inches thick by 0.25 inches wide by 36 inches long and weighs 0.65 pounds. O1 tool steel offers good machinability in the annealed state and responds well to oil-quench hardening, making it a standard choice for punches, dies, gauges, and small cutting tools. Thickness tolerance is held to plus or minus 0.001 inches, supporting close-tolerance work straight from stock.

This flat stock is suited for job shops, tool rooms, and maintenance departments that need a reliable, readily machinable tool steel in small cross-sections. The 36-inch length provides enough material for multiple short blanks or a single longer workpiece. It is commonly used by machinists and toolmakers to produce hand tools, jigs, blades, and wear components that require post-machining heat treatment. The square bar profile simplifies layout and setup on milling machines and surface grinders.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable heat-treat response
• Tight thickness tolerance of plus or minus 0.001 inches for close-tolerance blanks
• Width tolerance of 0.000 to minus 0.005 inches ensures stock fits into standard slots and grooves
• Length tolerance of plus 0.015 inches provides a cleanup allowance on each end
• Edge squareness held to 0.003 inches per inch on all edges
• Single 36-inch bar ships as one piece — no minimum quantity requirement beyond one unit

Compatibility

Designed as a standard O1 oil-hardening tool steel flat bar suitable for use wherever AISI Type O1 material is specified in toolmaking, die-making, or general machining applications.

Installation Notes

Cutting, grinding, and heat treatment of tool steel should be performed by qualified machinists or toolmakers familiar with O1 oil-quench hardening procedures. Use appropriate personal protective equipment when cutting or grinding. Follow established shop practices for annealing and hardening cycles — do not reference this listing for heat-treat temperatures or quench parameters, as those values are not part of this product record. Dispose of grinding swarf and cutting fluids in accordance with local regulations.