Type 420F (UNS S42020/1.4029)

Provides good ductility when annealed.
In a hardened condition, it offers excellent corrosion resistance.
Due to added sulfur, renders greatly improved machinability.
Chromium steel that can sustain heat treatment.

Description

Description

Equivalent Materials to Stainless steel UNS S31603 as a PDF file

Type 420F stainless steel is chromium, general-purpose steel, which can be heat treated. Due to the addition of sulfur in its composition, it provides greatly improved machinability.

Annealed, it offers good ductility. It renders excellent resistance to corrosion in the hardened condition.

It is similar to type 420, but stainless-steel type 420F is preferred in applications where good machining properties are required due to complex geometries, such as dental equipment, surgical equipment.

Common Names:

Stainless steel type 420F is commonly known as Chromium steel.

Executive Standards/Grades:

ASTM: A895
UNS: S42020
DIN: 1.4028
AISI: 420F
AMS: 5620

Chemical Properties:

Type 420F stainless steel has the following chemical composition:

Carbon – 0.15%
Manganese – 1.00%
Chromium – 13%
Sulphur – 0.15%
Phosphorus – 0.040%
Silicon – 1.00%
Molybdenum – 0.60%
Iron – 84%

Mechanical Properties:

Hardness (HRC) – 18
Elongation (%) – 22
Yield Strength (Mpa) – 380
Elastic Modulus (Gpa) – 210
Tensile Strength (Mpa) – 655
Poisson’s Ratio – 0.27-0.30

Physical Properties:

Density (x1000 kg/cm3) – 7.8
Thermal Conductivity (BTU in/hr.ft².°F) – 174
Specific Heat (Btu/lb/°F – [32-212 °F]) – 0.11
Electrical Resistivity (microhm-cm, at 68 oF) – 330
Thermal expansion (µin/in°F) – 5.72
Melting Point – 2650 °F

Key Features:

Excellent machinability properties, due to added sulfur.
Similar to type 420, but with free machining properties
Provides excellent resistance to corrosion when hardened
Can withstand heat treatment
Annealed, it provides good ductility
Not usually welded, due to hardening properties
Only minor cold work operations can be performed because it risks cracking

Forms Available: Stainless steel type 420F is available in different forms such as:

Pipe
Plate
Bar
Wire
Tube
Flanges
Fittings

Download as a PDF file

Applications:

Because of its properties, stainless steel type 420F has a wide range of applications including:

Cutlery
Dental and surgical equipment
Pump shafts
Gears
Hand tools
Steel balls
Cams
Pinions

Possible Alternatives Grades:

Type 420F stainless steel has some possible alternatives that can be used. Such as:

420 – Less machinable.
420J2 – Excellent corrosion, low cost.
430F – Good machinability
440F – High carbon, maximum hardness

FAQs:

Can stainless steel type 420F be hot worked and cold worked?

Type 420F stainless steel can withstand minimal cold work because it risked cracking. For hot working, it is recommended to slowly increase the temperature to 1400^oF, then to 2000-2200^oF. To prevent cracking, let it cool slowly in the furnace.

Can type 420F be welded?

Type 420F stainless steel is not usually welded, due to its hardening characteristics to air. However, if welding is necessary, it should be preheated to 300-400^oF and then tempered for 2 hours.