Starrett 54073 O1 Tool Steel Flat Stock 1/4x1-1/4x18 in

Product Description

The STARRETT 54073 is an O1 oil-hardening tool steel flat stock bar intended for toolmakers, machinists, and die makers who need a precision-ground blank for custom tooling, punches, dies, gauges, and fixtures. Made from AISI Type O1 tool steel, this flat bar measures 0.25 inches thick, 1.25 inches wide, and 18 inches long, with a weight of 1.59 pounds. Thickness tolerance is held to plus or minus 0.001 inches, giving the machinist a consistent starting point before hardening. O1 steel is known for its excellent machinability in the annealed state and its ability to achieve high hardness after oil quench.

This flat stock is suited for job shop, tool room, and maintenance machining applications where close-tolerance blanks are required. Typical uses include fabricating custom cutting tools, forming dies, jigs, and wear components that require through-hardening. The annealed supply condition allows straightforward milling, grinding, drilling, and turning before heat treatment. Machinists and toolmakers in both industrial and small-shop environments will find the 18-inch length practical for single-piece tool blanks or for cutting multiple shorter pieces.

Key Features

• AISI Type O1 oil-hardening tool steel for excellent machinability and good wear resistance after hardening
• Thickness tolerance of plus or minus 0.001 inches for a precision-ground starting surface
• Width tolerance of 0.000 to minus 0.005 inches ensures consistent stock width
• Length tolerance of plus 0.250 inches, minus 0 inches — parts arrive at or above nominal length
• Edge squareness held to 0.003 inches per inch on all edges
• Supplied in the annealed condition, ready for machining prior to heat treat

Compatibility

Designed as a standard O1 oil-hardening tool steel flat bar suitable for general tool room and die shop applications requiring AISI Type O1 material in 0.25-inch by 1.25-inch cross-section stock.

Installation Notes

Machining and heat treatment of O1 tool steel should be performed by qualified toolmakers or machinists familiar with tool steel handling procedures. All grinding, milling, and drilling should be completed in the annealed state before oil quenching. Follow the steel producer's recommended austenitizing temperature range and quench procedure for O1 during heat treatment. Allow stock to reach room temperature and verify flatness after quenching before finish grinding to final dimensions.