ASTM A 829 SAE 4140 structural quality alloy steel plate is a medium-carbon, chromium-molybdenum alloy which exhibits increased hardenability, strength, and wear resistance compared to plain carbon steels of the same carbon content. The ASTM A 829 SAE 4140 plates are usually furnished to chemical composition requirements only and are available from SSAB NAD in the as-rolled condition.

All A 829 SAE 4140 alloy steel plates supplied by SSAB NAD are vacuum degassed as part of the secondary steelmaking process. Through vacuum tank degassing of the liquid steel, a reduction of the dissolved gasses (hydrogen, nitrogen, oxygen) in the molten steel is achieved. This reduction of dissolved gasses and the associated removal of oxide inclusions from the liquid steel results in enhanced cleanliness of the steel and improved properties.

A 829 SAE 4140 alloy steel is ordinarily heat treated by the end user to the strength level desired for a specific application. Because A 829 SAE 4140 plate can be heat treated to achieve a range of properties, it is widely used for many general purpose parts requiring a combination of high strength and toughness. A 829 SAE 4140 alloy steel is also commonly employed for a variety of mold, tool and die applications as well as for machine bases and blocks.