Starrett 57178 A2 Tool Steel Flat Stock 5/16x1x18 Inch

Product Description

The STARRETT 57178 is an A2 air-hardening tool steel flat stock bar used in tool and die making, jig building, punch fabrication, and precision machining applications. It is supplied in the annealed condition, ready for machining, grinding, and heat treatment to working hardness. The bar measures 5/16 inches thick, 1 inch wide, and 18 inches long, and weighs 1.59 pounds. Thickness, width, and squareness tolerances are held to +0.010 to 0.015 inches, with a length tolerance of +0.25 inches. AISI A2 tool steel is known for its dimensional stability during air-hardening heat treatment, making it a reliable choice where tight post-heat distortion control is required.

This flat stock is suited for low- to medium-run tooling where A2 material properties are specified. Common applications include blanking dies, forming dies, trim dies, gauges, and precision ground flat components. Machinists, tool and die makers, and maintenance shops working with AISI A2 stock will find this bar suitable for stock removal, milling, and EDM operations prior to heat treat. The 18-inch length allows for straightforward sectioning into multiple tool blanks from a single piece.

Key Features

• AISI A2 air-hardening tool steel for dimensional stability during heat treatment
• Supplied in annealed condition, fully machinable before hardening
• Thickness and width tolerances of +0.010 to 0.015 inches for close-tolerance tooling work
• Squareness tolerance held to +0.010 to 0.015 inches
• Length tolerance of +0.25 inches
• Single-piece package quantity suitable for low-volume and prototype tooling needs

Compatibility

Designed as a standard AISI A2 air-hardening tool steel flat bar for use in tool and die, jig and fixture, and precision machining applications where A2 material specification is required.

Installation Notes

Cutting, grinding, and machining should be performed by qualified machinists or tool and die makers using appropriate tooling for hardened or semi-hardened steel. The bar should be fully machined to near-final dimensions before heat treatment, as A2 steel is air-hardened and requires a controlled atmosphere or vacuum furnace to minimize decarburization. Allow the bar to reach ambient temperature before inspection of critical tolerances after machining. Follow applicable shop safety practices when cutting or grinding tool steel, including use of appropriate PPE for metal chips and grinding sparks.