Starrett 54125 O1 Tool Steel Flat Stock 3/8x3x18 in

Product Description

The STARRETT 54125 is an O1 oil-hardening tool steel flat stock bar sized at 3/8 inches thick, 3 inches wide, and 18 inches long. AISI Type O1 tool steel is a general-purpose oil-hardening grade known for its dimensional stability during heat treatment and good wear resistance. This flat stock is machined to close tolerances, making it well-suited for fabricating tooling, dies, jigs, fixtures, and punches. The finished bar weighs approximately 5.74 pounds. Machinists, tool-and-die makers, and metalworking shops typically source this material for bench stock or job-specific blank cutting.

O1 flat stock in this size range is used in both small-shop and production toolroom environments. Typical applications include the manufacture of cutting tools, gauges, mold components, and precision fixture plates where a through-hardened or surface-hardened condition is needed after machining. The bar ships in annealed condition, allowing it to be machined to final shape before oil quenching and tempering to the desired hardness.

Key Features

• AISI Type O1 oil-hardening tool steel for good hardenability and wear resistance
• Thickness of 3/8 inches with tolerance of plus or minus 0.001 inches
• Width of 3 inches with tolerance of minus 0.000 to minus 0.005 inches
• Length of 18 inches with tolerance of plus 0.250 inches
• Edge squareness held to 0.003 inches per inch on all edges
• Supplied in annealed condition for ease of machining prior to heat treat

Compatibility

Designed as a standard AISI O1 oil-hardening tool steel flat bar for general toolroom and die-making applications requiring close-tolerance annealed stock.

Installation Notes

Cutting and machining of tool steel flat stock should be performed with appropriate metalworking equipment by qualified machinists or tool-and-die makers. Wear appropriate PPE including eye protection and gloves when cutting or grinding. Heat treatment — including oil quenching and tempering — should follow established metallurgical procedures for AISI O1 tool steel and be performed by qualified personnel. Do not use torch cutting methods where dimensional accuracy of the finished blank must be maintained.