What’s up guys? Michael here with Michael Talks Metal back for our last installment in the 440 series. Today our video will complete the alphabet of the 440 stainless steel variants. In prior episodes we talked about 440A and 440C.

What about 440B? Well, 440 B is the variant that has a carbon content of 0.75 % to 0.95 %; right in between 440A and 440C. It is not very popular and has no AMS standard.

Our final 440 type is 440 F; essentially 440 C but with an addition of an element that improves its machining characteristics. The most popular addition is Selenium and this type, 440F Se is recognized in AMS Standards as Type 2. A much less common version that uses Sulfur as the additional element is Type 1.

440F Se has the UNS designation S44023. It is a martensitic alloy that can be heat treated to the higher hardness and strength levels like 440C.
Typical applications require corrosion resistance, strength or hardness of 440C and the enhanced machinability justifies its added cost.

Typical annealing temperature is from 1550 to 1650 deg F followed by slow cooling.

Typical hardening range is 1800 to 1950 deg F followed by an air or oil quench depending on section size. Temper as required for desired hardness

Maximum corrosion resistance is achieved in the fully hardened condition.

440F Se is magnetic

440F Se SAE 51440F Se UNS S44023

Density: point 28 lbs per cubic inch

Mean Coefficient of Thermal Expansion from 32 -212 deg F:
5.7 microinch per inch per deg F

Machinability rating: 50 % (of 1212)

Chemical Composition 440F Se
Carbon0.95 – 1.20 %
Manganese1.00 % Max
Silicon1.00 % Max
Phosphorus0.040 % Max
Sulfur0.030 % Max
Chromium16.00 – 18.00 %
Nickel0.75 % Max
Molybdenum0.40 – 0.65 %
Selenium0.15 – 0.25 %
Copper0.75 % Max

Typical maximum hardness in the annealed condition: 255 BHN

Response to heat treatment in standard sample: 58 RC Minimum

Specifications for annealed condition:

AMS 5632 : Bars and Forgings: Type 2
Note: If no Type is specified, then either Type 1 or 2 can be supplied

ASTM and ASME standards for commercial applications are too numerous to detail here.

Refer to our website for more information and videos on stainless steels

Additional specifications and part requirements can alter what we have shown you here today.

SO CHECK THE SPECS !!!!!!!!!!!

Check out the earlier videos on stainless steels…. and visit us at our website