Starrett 54004 O1 Tool Steel Flat Stock 1/8x1-1/2x18 in

Product Description

The STARRETT 54004 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, jig fabrication, and precision machining applications. Manufactured to AISI Type O1 specification, this flat stock measures 1/8 inch thick, 1-1/2 inches wide, and 18 inches long, with a weight of 0.96 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. Machinists, tool and die makers, and metalworking shops rely on this material for its consistent dimensions and predictable oil-hardening heat treat response.

O1 tool steel flat stock is a standard material in job shops, maintenance departments, and toolrooms requiring precision-ground or close-tolerance stock for blanks, punches, guides, and wear components. The 18-inch length provides sufficient stock for most tooling blanks and small fixture components. This bar is suited for applications where the part will be machined to near-final dimensions and then oil-quenched to achieve working hardness. Fabricators working in both prototyping and production environments commonly use O1 flat stock as a baseline material before heat treating and finish grinding.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable heat treat response
• Thickness tolerance of plus or minus 0.001 inches for consistent stock removal
• Width tolerance of 0.0000 to 0.0050 inches for close-fit applications
• Length tolerance of plus 0.250 inches for full usable length
• Squareness held to 0.003 inches per inch on all edges
• 0.96 pounds per bar — suitable for bench and machine handling

Compatibility

Designed as a standard O1 oil-hardening tool steel flat bar for general toolmaking, die, and precision fabrication applications requiring AISI Type O1 material specification.

Installation Notes

Cutting, drilling, and milling should be performed with tooling rated for tool steel. Oil quenching should follow AISI O1 heat treat guidelines for the specific cross-section and hardness target. Always allow the material to reach ambient temperature before taking final measurements. Wear appropriate PPE when machining or heat treating tool steel.