Starrett 57004 O1 Tool Steel Flat Stock 3/8x2x18 in

Product Description

The STARRETT 57004 is a precision-ground flat stock bar made from AISI Type O1 oil-hardening tool steel. It measures 3/8 inch thick, 2 inches wide, and 18 inches long, with tight dimensional tolerances of +0.010 to +0.015 inches on thickness and width, and a length tolerance of +0.250 inches. Edge squareness is held to 0.003 inches per inch across all edges. This stock is used by machinists, toolmakers, and die makers who need a reliable, weldable, and machinable blank that responds predictably to oil-quench hardening. At 3.82 pounds, it is a practical size for benchtop layout and cutting operations.

O1 tool steel flat stock is a standard choice for fabricating punches, dies, gauges, jigs, fixtures, and general-purpose tooling. The 3/8-inch thickness makes it suitable for applications requiring moderate cross-section strength before or after hardening. This bar is sized for single-piece use in a machine shop or tool room and arrives ready for layout, machining, and heat treatment. It is appropriate for both production tooling and one-off prototype work where dimensional consistency and material traceability matter.

Key Features

• AISI Type O1 oil-hardening tool steel for predictable heat-treat response
• Thickness and width held to +0.010 to +0.015 inches tolerance
• Edge squareness: 0.003 inches per inch on all edges
• Length tolerance of +0.250 inches for single-piece cut stock
• 3/8 x 2 x 18 inch dimensions suit a wide range of tooling blanks
• Ships as a single piece — no minimum quantity beyond one bar

Compatibility

Designed as a standard O1 oil-hardening tool steel flat bar for general machine shop, toolroom, and die-making applications where AISI Type O1 material specification is required.

Installation Notes

Machining and grinding of O1 tool steel should be performed by qualified machinists using appropriate cutting fluids and tooling rated for hardened or pre-hardened steel. Heat treatment — including austenitizing and oil quenching — should follow the material manufacturer guidelines and be performed by personnel familiar with tool steel processing. Always wear appropriate PPE when cutting, grinding, or heat-treating steel stock. Verify final dimensions after any heat treatment, as some dimensional change is normal during hardening.