Starrett 54182 O1 Tool Steel Flat Stock 5/8x5x18 in

Product Description

The STARRETT 54182 is an O1 oil-hardening tool steel flat stock bar used in toolmaking, die work, and precision machining applications. It is manufactured from AISI Type O1 tool steel, a general-purpose oil-hardening grade known for its dimensional stability after heat treatment and good wear resistance. This bar measures 5/8 inch thick, 5 inches wide, and 18 inches long, with a thickness tolerance of plus or minus 0.001 inches and a width tolerance of 0.000 to 0.005 inches. At 15.58 pounds, it is ready for bench or saw cutting before hardening. Machinists, toolmakers, and die shops rely on this stock for blanks, fixtures, and tooling components requiring tight dimensional control.

O1 flat stock in this size range is commonly used in job shops and tool-and-die operations for producing punches, dies, gauges, jigs, and custom tooling components. The 18-inch length provides a practical working blank that can be cut to final dimensions on a band saw or cold saw before soft machining and subsequent oil-hardening heat treatment. This bar is suitable for applications where close tolerances must be held in the annealed condition prior to hardening and grinding to final size.

Key Features

• AISI Type O1 oil-hardening tool steel — standard grade for tooling, dies, and precision fixtures
• Thickness tolerance of plus or minus 0.001 inches for consistent stock removal during grinding
• Width tolerance of 0.000 to minus 0.005 inches for predictable fit in fixture and die applications
• Length tolerance of plus 0.250 inches, providing usable extra material for final facing
• Squareness held to 0.003 inches per inch on all edges for reliable reference surfaces
• Weighs 15.58 pounds — substantial bar suitable for large blanks or multiple smaller pieces

Compatibility

Designed as a standard annealed O1 tool steel flat bar suitable for toolmaking, die-making, and precision machining operations where oil-hardening heat treatment will be applied after rough machining.

Installation Notes

Cutting and machining of this bar should be performed in the annealed condition using carbide or high-speed steel tooling with appropriate cutting fluids. Oil-hardening heat treatment should be performed by a qualified heat treater following AISI O1 specifications; improper quenching can result in cracking or distortion. Always use personal protective equipment including eye protection and cut-resistant gloves when cutting or handling tool steel stock. Verify final dimensions by grinding after hardening and tempering, as dimensional change during heat treatment is expected.