After reading Orchid for a while now, I though the following may
be of interest to some members. I have to admit that it is fairly
well generalized, but does give an overall view.
There are 4 common types of steel that you can encounter:
Plain carbon/low alloy - Plain carbon and low alloy steels
make up most of the steel made. These steels are used to make
nails, screws, hasps, hinges, rails, brackets, auto springs, etc.
Designations for these steels include 1018, 1020, 1040, 4140,
4150, 8620, etc.
Hardenable stainless steels - Hardenable stainless steel is
used where a hard, corrosion resistant material is needed, either
for cosmetics such as knife blades or where the application
requires it. Designations for these steels include 410, 420,
440C, etc. These are not as “stainless” as the non-hardenable
grades shown below.
Tool Steels - Tool steels are special purpose steels used for
dies, punches, shear blades, drill bits, router bits, etc.
Designations for these steels include A-2, O-1, D-2, S-2, M-2,
The above steels are all hardenable to greater or lesser degrees
depending on the grade, by heating above approximately 1350F and
rapidly cooling them. The cooling rate needed for full hardening
depends on the grade. Steels like 1018 or 1020 require very rapid
cooling while 410, 420, 440 or A2 only need an air cool.
One other thing these steels all have in common is that they are
- Non-hardening stainless steels - These stainless steels are
relatively soft (Rb 60 - Rb 100) and used for flatware,
decorative trim, jewelry, etc. Designations for these steels
include 302, 303, 304, 310, 316, etc.
The annealing of these steels is similar to gold, silver &
copper alloys in that you heat them to a high temperature ( 1800F
- 2000F ) and quench to anneal and obtain the lowest hardness.
This also gives the most corrosion resistance in these steels.
The difference is that you cannot appreciably harden it by aging.
These steels are all Non-magnetic.
Hope you can use it