Starrett 54551 A2 Tool Steel Flat Stock 0.125x3x36 in

Product Description

The STARRETT 54551 is an A2 air-hardening tool steel flat stock bar intended for toolmakers, die makers, and machinist trades requiring tight-tolerance raw material for fabricating dies, punches, jigs, fixtures, and gauges. The bar measures 0.125 inches thick, 3 inches wide, and 36 inches long, and carries a weight of 4.4 pounds per bar. A2 tool steel offers good toughness combined with moderate wear resistance and is air-hardened after machining, which minimizes distortion during heat treatment. Thickness and squareness tolerances are held to plus or minus 0.001 inches, making this stock suitable for precision tooling applications where dimensional stability matters before and after hardening.

This flat stock is used in tool rooms, job shops, and maintenance departments for fabricating cutting tools, forming dies, blanking dies, and wear plates. It is appropriate for both one-off prototype tooling and short-run production tooling. The 36-inch length allows a single bar to be cut into multiple blanks. A2 material is a common specification in AISI tool steel standards and is widely specified on engineering drawings for cold-work tooling applications operating at moderate speeds and pressures.

Key Features

• AISI A2 air-hardening tool steel — minimizes distortion during heat treat compared to oil-hardening grades
• Thickness tolerance of plus or minus 0.001 inches for consistent stock removal during grinding
• Width tolerance of plus 0.000 to 0.005 inches
• Length tolerance of plus 0.25 inches
• Squareness held to 0.003 inches per inch on all edges
• Square tolerance of plus or minus 0.001 inches

Compatibility

Designed as a standard AISI A2 air-hardening tool steel flat bar suitable for cold-work tooling fabrication where air-quench heat treatment and low distortion are specified.

Installation Notes

Cutting, grinding, and drilling of tool steel flat stock should be performed with coolant to prevent localized overheating that can affect material properties. Heat treatment of A2 tool steel should be performed by a qualified heat treater following AISI guidelines for austenitizing temperature and air-quench procedures. All machining to final dimensions should be completed prior to hardening. Personal protective equipment including eye protection and gloves is required when cutting or grinding this material.