1.4021 vs 1.4401 stainless steel

What is 1.4401 steel?

Stainless steel types 1.4401 (also known as grade 316) is an austenitic grade second only to 304 in commercial importance. It has similar mechanical properties to 304 but is stronger at elevated temperatures. 316 stainless steel contains an addition of molybdenum that gives it improved corrosion resistance.

What is 1.4021 stainless steel?
Stainless steel 1.4021(also known as grade 420) is a martensitic machining bar with machinability improved with the addition of Sulphur. The Sulphur also lowers weldability, corrosion resistance, and formability to below that of its non-free machining equivalent Grade 410.

 

What material is equivalent to 1.4401?

316 stainless steel is a really common stainless steel grade and it is one of the most widely used stainless steel grade around the world. This grade is written as 1.4401 or X5CrNiMo17-12-2 according to EN norm and it is written as UNS S31600 according to UNS norm.

 

What material is 1.4021 equivalent to?

The 1.4021 stainless steel material is equivalent to AISI 420 and X20Cr13. It's a martensitic stainless steel known for its high tensile strength and good corrosion resistance. It is often used in applications like shafts, pump parts, and nuts.

 

Key Differences Between 1.4021 and 1.4401

 

1. Chemical Composition

Element	1.4021 (Martensitic)	1.4401 (Austenitic)
Carbon (C)	0.16–0.25%	≤0.07%
Chromium (Cr)	12.0–14.0%	16.0–18.0%
Nickel (Ni)	≤0.6%	10.0–14.0%
Molybdenum (Mo)	0% (none)	2.0–3.0%
Manganese (Mn)	≤1.5%	≤2.0%

2. Mechanical Properties

Property	1.4021 (Quenched & Tempered)	1.4401 (Solution Annealed)
Tensile Strength	650–850 MPa	500–700 MPa
Yield Strength	≥450 MPa	≥200 MPa
Hardness (HB)	200–250	≤215
Elongation	≥15%	≥40%
Impact Toughness	20–40 J (room temp)	≥100 J (room temp)

 

3. Corrosion Resistance

1.4021 stainless steel has moderate corrosion resistance, suitable for dry or mildly corrosive environments, while 1.4401 offers much higher corrosion resistance, especially in chloride-rich or marine conditions.

 

4. Processing & Fabrication

How easy they are to machine, weld, or shape affects manufacturing efficiency:

Process	1.4021	1.4401
Machining	Good in annealed state; hardens quickly when worked.	Excellent-low work-hardening rate.
Welding	Poor-prone to cracking; requires pre/post-heat treatment.	Excellent-compatible with TIG/MIG; no heat treatment needed.
Heat Treatment	Required (quenching + tempering) to achieve strength.	Not needed-solution annealing optimizes corrosion resistance.

5.Cost

1.4021 stainless steel is typically 30–40% less expensive than 1.4401. Its low nickel content and lack of molybdenum reduce raw material costs, making it ideal for budget-sensitive projects where corrosion resistance is less critical.

 

Can 1.4021 replace 1.4401 ?

Rarely. 1.4021 lacks corrosion resistance for 1.4401's applications, and 1.4401 can't match 1.4021's strength/wear resistance.

 

Is 1.4021 magnetic?

Yes (martensitic structure). 1.4401 is non-magnetic (austenitic structure)-critical for applications like MRI equipment or sensors.