Starrett 54130 O1 Tool Steel Flat Stock 3/8x5-1/2x18 in

Product Description

The STARRETT 54130 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, jig fabrication, die work, and precision machining applications. Manufactured from AISI Type O1 tool steel, this flat bar measures 3/8 inches thick, 5-1/2 inches wide, and 18 inches long. It ships in pre-cut, ready-to-use form with tightly controlled tolerances: plus or minus 0.001 inches on thickness, a length tolerance of plus 0.250 inches, and a width tolerance of 0.000 to 0.005 inches. Edge squareness is held to 0.003 inches per inch across all edges. Machinists, toolmakers, and die makers rely on O1 flat stock for its consistent hardening response and predictable dimensional stability before heat treatment.

This flat stock is suited for fabricating punches, dies, gauges, fixtures, and cutting tools in machine shops, tool-and-die operations, and manufacturing maintenance departments. The O1 grade oil-hardens at relatively low temperatures compared to other tool steels, which reduces distortion risk during the hardening process. It is commonly worked in the annealed condition using standard milling, drilling, grinding, and turning operations before hardening. The 18-inch length provides a practical working blank for most bench and machine work without requiring further rough cutting in many applications.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable, low-distortion heat treatment response
• Thickness tolerance of plus or minus 0.001 inches for precise stock removal planning
• Width tolerance of 0.000 to 0.005 inches for consistent fitment in tooling setups
• Length tolerance of plus 0.250 inches — allows facing to exact length without undersize risk
• Edge squareness held to 0.003 inches per inch on all edges
• Pre-cut 18-inch length ships ready for layout and machining in annealed condition

Compatibility

Designed as a general-purpose O1 oil-hardening tool steel flat blank for toolmaking, die making, and precision machining applications requiring tight dimensional tolerances and consistent hardenability.

Installation Notes

O1 tool steel flat stock is typically machined in the annealed condition using conventional milling, drilling, and grinding equipment. Heat treatment to harden the steel should be performed by a qualified tool-and-die maker or heat treatment professional following established metallurgical procedures for AISI O1 tool steel. Always allow stock to reach room temperature before performing precision layout or finish grinding. Handle with care during storage to prevent edge nicks that could affect squareness and tolerance compliance.