Starrett 54011 O1 Tool Steel Flat Stock 0.125x4.5x18 in

Product Description

The STARRETT 54011 is an O1 oil-hardening tool steel flat stock bar used in tool and die work, jig and fixture fabrication, and precision machining applications. Made from AISI Type O1 tool steel, it measures 0.125 inches thick, 4.5 inches wide, and 18 inches long, with a weight of 2.87 pounds. O1 tool steel is valued for its machinability in the annealed state and its ability to hold a sharp edge after hardening. Thickness tolerance is held to plus or minus 0.001 inches, making this stock suitable for applications that require dimensional consistency before finish grinding or hardening operations. Machinists, tool makers, and die makers are the primary users of this material.

This flat stock is suited for small to medium tooling applications in job shops, tool rooms, and maintenance departments. The 18-inch length provides practical stock for layout, machining, and cut-to-length use. The 4.5-inch width makes it well suited for blanks, wear plates, forming dies, and similar tool room components. The pre-cut, ready-to-use format reduces setup time compared to cutting from full bar stock. Edge squareness is held to 0.003 inches per inch on all edges, supporting accurate layout and machining from stock.

Key Features

• AISI Type O1 oil-hardening tool steel for reliable hardenability and edge retention
• Thickness of 0.125 inches with plus or minus 0.001 inch tolerance for precision fitment
• Width of 4.5 inches with tolerance of 0.000 to minus 0.005 inches
• Length of 18 inches with plus 0.250 inch length tolerance
• Edge squareness held to 0.003 inches per inch on all edges
• Ready-to-machine annealed condition suitable for milling, drilling, and grinding

Compatibility

Designed as a general-purpose O1 oil-hardening tool steel flat bar for use in tool rooms, die shops, and precision fabrication environments where AISI Type O1 material specification is required.

Installation Notes

Machining and hardening of O1 tool steel should be performed by qualified machinists or tool makers familiar with tool steel heat treatment procedures. Use appropriate cutting fluids when milling or grinding. Hardening and tempering operations require controlled furnace equipment and should follow established metallurgical procedures for AISI O1 to avoid cracking or distortion. Handle flat stock carefully on edges to protect ground surfaces and maintain dimensional accuracy prior to use.