Drill Rod Tool Steels 81173403 4142 Alloy Steel Flat Stock

Product Description

The DRILL ROD TOOL STEELS 81173403 is a pre-hardened alloy steel flat stock bar conforming to AISI/SAE Type 4142 specification. It measures 18 inches long, 2.5 inches wide, and 0.125 inches thick, and weighs 1.59 pounds. The 4142 chromium-molybdenum alloy composition delivers high strength, good toughness, and moderate wear resistance in the pre-hardened condition, making it suitable for tooling, fixtures, die components, jigs, and structural machine parts. Machinists, tool-and-die makers, and metalworking fabricators work with this material when a through-hardened flat bar is required without additional heat treatment steps.

This flat stock is used in applications that demand a combination of strength and machinability in alloy steel. Typical uses include machined fixtures, support brackets, tooling plates, wear components, and fabricated structural members in industrial and manufacturing environments. The pre-hardened condition allows the part to be cut, drilled, and milled directly to final dimensions without the distortion risks associated with post-machining heat treatment. It is suited for both light production runs and one-off tooling work.

Key Features

• AISI/SAE Type 4142 chromium-molybdenum alloy steel, pre-hardened for immediate use
• Nominal dimensions: 18 inches long x 2.5 inches wide x 0.125 inches thick
• Length tolerance: +0.125 inches / -0.000 inches
• Width tolerance: +0.005 inches / -0.000 inches
• Thickness tolerance: +0.001 inches
• Square tolerance: 0.003 inches
• Pre-hardened condition eliminates need for post-machining heat treatment

Compatibility

Designed as a standard AISI/SAE Type 4142 pre-hardened alloy steel flat bar suitable for general tooling, fixture, and structural fabrication applications where a through-hardened chromium-molybdenum flat stock is specified.

Installation Notes

This material is worked by machinists, tool-and-die makers, and metal fabricators using conventional milling, drilling, sawing, and grinding equipment appropriate for hardened alloy steel. Carbide or high-speed steel tooling rated for hardened steel is recommended. Welding pre-hardened 4142 requires preheat and post-weld heat treatment procedures per applicable welding codes to avoid hydrogen cracking; consult a qualified welding engineer before attempting weld repairs. Always use appropriate personal protective equipment when cutting or grinding steel stock.