Starrett 54127 O1 Tool Steel Flat Stock 3/8x4x18 in

Product Description

The STARRETT 54127 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die making, and precision machining applications. Manufactured to AISI Type O1 specification, this flat stock measures 3/8 inch thick, 4 inches wide, and 18 inches long, with a weight of 7.65 pounds. Thickness and squareness tolerances are held to plus or minus 0.001 inches, making it suitable for applications that require close dimensional control before and after heat treatment. O1 tool steel is known for its stable hardening response in oil-quench operations and good machinability in the annealed state.

This flat stock is used in tool and die shops, maintenance machining environments, and industrial fabrication settings. Typical applications include blanking dies, gauges, punches, forming tools, and precision fixtures. The 3/8 x 4 x 18 inch size suits medium-scale tooling work where a full-width blank needs to be cut down, ground, or machined to a finished profile. It is handled primarily by tool and die makers, machinists, and maintenance technicians who require reliable pre-hardened or ready-to-harden flat bar stock.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable heat treatment response
• Thickness tolerance of plus or minus 0.001 inches for tight dimensional control
• Width tolerance of 0.000 to minus 0.005 inches
• Length tolerance of plus 0.250 inches, minus 0 inches
• Squareness held to 0.003 inches per inch on all edges
• Supplied in annealed condition, ready for machining prior to hardening

Compatibility

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

Installation Notes

Tool and die makers and machinists work this material in the annealed state using conventional milling, drilling, and grinding equipment. Oil-hardening heat treatment should be performed by qualified personnel following established metallurgical procedures for AISI O1 tool steel. Allow the workpiece to reach ambient temperature before final grinding to finished tolerance. Proper personal protective equipment is required when cutting, grinding, or heat treating tool steel.