Grade 416 steel is a free-machining stainless steel with a machinability of 85%, highest of all stainless steels. With most of the free-machining stainless steels, the machinability can be improved by adding sulphur, which leads to the formation of manganese sulphide inclusions. Addition of sulphur also reduces the formability, weldability and corrosion resistance of 416 steels to below that of grade 410. Because of their high machinability and low cost, grade 416 steels are available in highly tempered, hardened or unhardened forms.

Martensitic steels with high hardness are manufactured using methods that require final hardening and tempering treatments. The corrosion resistance of these steels is lower than that of austenitic steels. Decrease in the ductility of martensitic steels at sub-zero temperatures, and strength at high temperatures due to over-tempering, are the two key factors that affect their operating temperatures.

Key Properties

The following sections will discuss the properties of grade 416 steel bar products of ASTM A582. The specified properties may not be similar to other forms such as forgings and wires.

Composition

The chemical composition ranges of grade 416 stainless steels are given in the following table:

Table 1 - Composition ranges for grade 416 stainless steels

Mechanical Properties

The table below provides the mechanical properties of grade 416 stainless steels:

Table 2 - Mechanical properties of grade 416 stainless steels