Starrett 54420 O1 Tool Steel Flat Stock 3/8x5.5x36 in

Product Description

The STARRETT 54420 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, and precision machining applications. Manufactured to AISI Type O1 material specification, this flat stock measures 3/8 inch thick, 5-1/2 inches wide, and 36 inches long, with a finished weight of 21.03 pounds. Thickness tolerance is held to +/- 0.001 inches, making it suitable for applications that require close dimensional control before and after heat treatment. Machinists, tool and die makers, and metalworking professionals use this stock as a starting material for custom tooling, fixtures, gauges, and punches.

O1 tool steel flat stock is a standard choice for job shops and production tool rooms handling general-purpose toolmaking work. Its oil-hardening characteristic allows controlled heat treatment with minimal distortion, which is important when the finished tool must maintain dimensional accuracy. This bar is sized for larger tooling projects where width and length provide enough material for layout, machining, and finishing operations. Typical applications include blanks for flat dies, wear plates, shims, and precision fixtures in both small-shop and industrial settings.

Key Features

• AISI Type O1 oil-hardening tool steel material specification
• Tight thickness tolerance of +/- 0.001 inches for precision stock removal
• Width tolerance held to 0.0000 to -0.005 inches for consistent fit
• Length tolerance of +0.015 inches ensures full usable length
• Edge squareness held to 0.003 inches per inch on all edges
• Single-piece packaging suitable for low-volume toolroom procurement

Compatibility

Designed as a general-purpose O1 oil-hardening tool steel flat stock suitable for standard toolmaking, die making, and precision machining applications where AISI Type O1 material specification is required.

Installation Notes

Cutting and machining of tool steel flat stock should be performed by qualified machinists using appropriate metalworking equipment and tooling rated for tool steel hardness. Heat treatment of O1 steel requires oil quenching and must be performed according to established metallurgical procedures for AISI O1 alloy. Always de-burr cut edges before handling and use appropriate personal protective equipment when sawing or grinding. Follow applicable shop safety standards when working with raw tool steel stock.