Starrett 54218 O1 Tool Steel Flat Stock 1x4x18 Inch

Product Description

The STARRETT 54218 is an O1 oil-hardening tool steel flat stock bar measuring 1 inch thick, 4 inches wide, and 18 inches long. Manufactured from AISI Type O1 tool steel, this flat stock is supplied in the annealed condition and intended for toolmakers, machinists, and die makers who require a machinable blank that responds predictably to oil-hardening heat treatment. The tight thickness tolerance of plus or minus 0.001 inches and a squareness tolerance of 0.003 inches per inch along all edges make this stock suitable for precision tooling applications where dimensional control before and after hardening is critical. It weighs approximately 20.4 pounds.

This flat stock is used in tool and die shops, maintenance machining operations, and jobbing environments where custom punches, dies, gauges, jigs, and fixtures are fabricated from raw material. O1 grade tool steel machines cleanly in the annealed state and offers good wear resistance after hardening and tempering. It is well suited for low-to-medium production tooling where the oil-quench process provides less distortion risk than water-hardening grades. This bar is appropriate for applications where the finished tool will see moderate shock loads and abrasion.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable heat-treat response
• Thickness tolerance of plus or minus 0.001 inches for precise pre-grind stock allowance
• Width tolerance of 0.000 to minus 0.005 inches, length tolerance of plus 0.250 inches
• Squareness held to 0.003 inches per inch on all edges
• Supplied in annealed condition for full machinability prior to hardening
• Single-piece packaging with no minimum order beyond one unit

Compatibility

Designed as a standard O1 oil-hardening tool steel flat stock blank for use in general tool and die fabrication, gauge making, and precision machining applications requiring AISI Type O1 material.

Installation Notes

Machining and heat treatment of tool steel should be performed by qualified toolmakers or machinists familiar with O1 oil-hardening procedures and applicable shop safety practices. Always follow established heat-treat protocols for AISI O1 including proper soak temperature, oil quench, and temper cycle to achieve target hardness and minimize distortion. Use appropriate personal protective equipment when cutting, grinding, or heat treating this material. Secure the bar properly in vises or fixtures before any machining operations to prevent movement and injury.