Starrett 57058 O1 Tool Steel Flat Stock 1x2.5x18 in

Product Description

The STARRETT 57058 is an O1 oil-hardening tool steel flat stock bar measuring 1 inch thick, 2-1/2 inches wide, and 18 inches long. O1 is an AISI-standard oil-hardening grade known for good wear resistance and dimensional stability through the hardening process. This flat stock ships in the annealed condition, ready for machining before heat treatment. It is used by tool and die makers, machinists, and metalworking shops to fabricate punches, dies, gauges, blades, and other precision tooling. Thickness and width tolerances are held to +0.010 to +0.015 inches, with a length tolerance of +0.250 inches and edge squareness of 0.003 per inch.

This bar is suited for job-shop and production environments where close-tolerance tool steel stock is needed for custom tooling fabrication. The 18-inch length makes it practical for die components, wear plates, and fixture elements. At 12.75 pounds per piece, it is a substantial bar appropriate for heavier tooling applications. Metalworking professionals sourcing pre-cut flat stock for short-run tooling or prototype work will find this size a commonly specified starting dimension.

Key Features

• AISI Type O1 oil-hardening tool steel — designed for oil quench heat treatment after machining
• Thickness and width held to +0.010 to +0.015 inches tolerance for close-tolerance fitment
• Edge squareness of 0.003 inches per inch on all edges
• Length tolerance of +0.250 inches — supplied long for finish-cut to final dimension
• Ready-to-machine annealed condition before hardening
• Single-piece minimum order quantity — no bulk commitment required

Compatibility

Designed as a standard AISI Type O1 oil-hardening tool steel flat stock for general tooling and die-making applications where 1-inch by 2-1/2-inch cross-section material is specified.

Installation Notes

Machining and heat treatment of tool steel flat stock should be performed by qualified machinists or tool and die makers familiar with O1 oil-hardening procedures. Machine to final dimensions before hardening, as post-hardening machining requires grinding. Heat treatment should follow the material manufacturer's recommended austenitizing and quench procedures for AISI O1 steel. Always use appropriate personal protective equipment when cutting, grinding, or heat-treating tool steel.