Starrett 54121 O1 Tool Steel Flat Stock 3/8x1-1/2x18in

Product Description

The STARRETT 54121 is a precision-ground O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, and general machining applications. It measures 3/8 inch thick, 1-1/2 inches wide, and 18 inches long, with a weight of 2.87 pounds. The material conforms to AISI Type O1 specification, a widely used oil-hardening tool steel known for its dimensional stability during heat treat and its machinability in the annealed state. Thickness tolerance is held to plus or minus 0.001 inches, making this bar suitable for applications where close stock allowance before finish grinding is required. Machinists, tool and die makers, and metalworking shops are the primary users of this material.

This flat stock is suited for fabricating punches, dies, gauges, jigs, fixtures, and cutting tools in job shop and production toolroom environments. It arrives in the annealed (soft) condition, ready for machining to final shape before oil-hardening heat treatment. The 18-inch length is a standard drop size commonly stocked for toolroom use. Applications range from small fixture components to blanks for form tools and wear plates where post-heat-treat hardness is required.

Key Features

• AISI Type O1 oil-hardening tool steel — machines well in the annealed state and hardens consistently in oil quench
• Thickness tolerance of plus or minus 0.001 inches for predictable stock allowance before finish grinding
• Width tolerance of 0.0000 to minus 0.005 inches
• Length tolerance of plus 0.250 inches, minus 0 inches
• Edge squareness held to 0.003 inches per inch on all edges
• Single-piece packaging — sold as one bar per unit

Compatibility

Designed as a standard AISI O1 oil-hardening tool steel flat bar suitable for general toolroom and die-making applications where O1 material specification is required.

Installation Notes

Cutting, grinding, and machining of tool steel flat stock should be performed by qualified machinists or tool and die makers using appropriate metalworking equipment. Work in the annealed condition before heat treatment. Heat treating O1 steel requires controlled furnace temperatures and an oil quench — this process should be performed by qualified personnel following established metallurgical procedures. Always wear appropriate PPE when cutting or grinding tool steel bar stock.