Starrett 58896 O1 Tool Steel Flat Stock 5/16x5/8x36 in

Product Description

The STARRETT 58896 is a precision-ground flat stock bar made from AISI Type O1 oil-hardening tool steel. It measures 5/16 inches thick, 5/8 inches wide, and 36 inches long, weighing approximately 1.99 pounds. O1 tool steel is a versatile cold-work grade known for its excellent machinability in the annealed state and its ability to achieve high hardness after oil quenching. This stock is held to tight dimensional tolerances, making it suitable for toolmakers, machinists, and die makers who require consistent raw material for cutting tools, punches, dies, and precision fixtures.

This flat stock is used in machine shops, tool-and-die operations, and fabrication environments where a reliable, close-tolerance O1 blank is needed before heat treatment. It arrives in the soft, annealed condition, ready for machining to final shape prior to hardening and tempering. Typical applications include gauge blanks, form tools, wear strips, and small die components where dimensional consistency from the raw bar is critical to finished part accuracy.

Key Features

• AISI Type O1 oil-hardening tool steel for excellent machinability and predictable heat-treat response
• Thickness tolerance of plus or minus 0.001 inches for consistent stock removal in finishing operations
• Width tolerance of 0.000 to minus 0.005 inches for precise fit in die sets and fixtures
• Length tolerance of plus 0.015 inches, minus 0 inches — stock is never undersized in length
• Edge squareness held to 0.003 inches per inch on all edges
• Single-piece package quantity supports low-volume toolroom and prototype work

Compatibility

Designed as a standard annealed O1 tool steel flat bar suitable for machining into punches, dies, gauges, wear strips, and similar toolroom components that require oil-hardening heat treatment to achieve final hardness.

Installation Notes

O1 tool steel flat stock is machined by experienced toolmakers and machinists using conventional milling, grinding, and turning equipment. Always machine to final dimensions before hardening. Heat treatment — including austenitizing, oil quenching, and tempering — should be performed by qualified personnel following established metallurgical procedures for O1 grade tool steel. Secure workpieces properly during machining to maintain the tight tolerances this stock is ground to.