Alloy Plate - 4140
/ 4340 / 8620 - ASTM A 829
Standard specification for Alloy Steel Plate Furnished to Chemical
ASTM A 829 was first issued in 1984; prior to that these grades
were defined by AISI specifications.
This specification covers structural quality alloy steel plates
furnished to chemical composition requirements only. There are
no tensile requirements or other mechanical property requirements
for this specification.
The ASTM A 829 specification covers 30 standard chemistries.
Oliver Steel offers these chemistry-only alloy plate grades in
the three most commonly used chemistries. 4140 is the standard
for medium carbon chromium-molybdenum alloy with excellent response
to quench-and-temper and moderate through hardening capabilities;
at Oliver, our 4140 is modified to include a small amount of
vanadium for even better hardening. 4340 includes nickel for
higher overall hardness and superb through hardening. 8620 is
alloyed for as-rolled core strength but can be readily carburized.
General requirements for delivery
Material shall conform to the requirements of ASTM A 6.
Single values are maximums.
There are no mechanical property requirements for these grades.
Generally, the alloy content provides the potential for these
steels to achieve certain mechanical properties when they are
subjected to the appropriate thermal treatment process. This
is usually performed after flamecutting or sawcutting, and
is done to achieve the specific properties required by the
end-use application. Oliver provides a complete range of thermal
treatment process options.