What is 1.4117 Stainless Steel?

1.4117 stainless steel, commonly known as 440A or UNS S44002, is a high-carbon martensitic stainless steel that offers a good balance of hardness, corrosion resistance, and toughness. As the lower carbon member of the 440 series, it provides slightly lower hardness than 440B and 440C but offers improved toughness and better corrosion resistance due to fewer chromium carbides. This makes it suitable for applications requiring moderate wear resistance, good edge retention, and adequate corrosion resistance, such as cutlery, bearings, surgical instruments, and valve components.

 

This medium-hardness martensitic grade is recognized under several international standards.

Standard	Equivalent Grade
EN (Europe)	1.4117
ASTM/AISI (USA)	440A, UNS S44002
JIS (Japan)	SUS440A
Common Name	440A

Its carbon content is lower than 440B and 440C, providing a better balance of hardness and toughness.

Element	C	Si	Mn	P	S	Cr	Mo
Content (%)	0.60 - 0.75	≤ 1.0	≤ 1.0	≤ 0.04	≤ 0.03	16.0 - 18.0	≤ 0.75

Mechanical properties vary significantly with heat treatment, offering good hardness with improved toughness.

Condition	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HRC)
Annealed	~ 450 MPa	~ 740 MPa	~ 15%	~ 25 HRC
Hardened & Tempered	≥ 550 MPa	≥ 700 MPa	≥ 12%	52 - 56 HRC

 

Key Characteristics and Applications of 1.4117 / 440A

Good Balance of Hardness and Toughness: Lower carbon content provides slightly lower maximum hardness than 440B or 440C but offers better toughness, making it less brittle and more resistant to chipping.

Moderate Corrosion Resistance: Offers better corrosion resistance than 440B and 440C due to fewer chromium carbides in the microstructure, with performance similar to 420 in most environments.

Magnetic and Hardenable: Strongly magnetic and responds well to heat treatment, with good through-hardening capability.

Good Wear Resistance: Provides adequate wear resistance for many applications without the brittleness of higher carbon grades.

 

Primary Applications:

Cutlery: Mid-range knives, blades, scissors, and kitchen utensils requiring a balance of edge retention and toughness.

Bearings: Ball bearings and races for less demanding applications.

Surgical Instruments: Instruments requiring sharp edges and good corrosion resistance.

Valve Components: Seats, balls, and stems in moderate wear applications.

Industrial Tools: Gauges, measuring tools, and machine parts requiring dimensional stability.

Dental Tools: Instruments requiring sterilization resistance and good edge retention.

 

How does 440A (1.4117) compare to 440B (1.4112) and 440C (1.4125)?
The 440 series differs primarily in carbon content: 440A has 0.60-0.75% C, 440B has 0.75-0.95% C, and 440C has 0.95-1.20% C. This results in 440A offering the lowest maximum hardness (56 HRC vs. 58 HRC for 440B and 62 HRC for 440C) but the best toughness and corrosion resistance. 440A is less brittle and more resistant to chipping than the higher carbon grades, making it suitable for applications where impact resistance is important. It is also more readily available and less expensive than 440C. 440A is often chosen for applications where a balance of hardness, toughness, and corrosion resistance is needed without the extreme hardness (and brittleness) of 440C.

 

What is the recommended heat treatment for 440A stainless steel?
Typical heat treatment for 440A involves:

Austenitizing: Heat to 1010-1065°C, hold for sufficient time to dissolve carbides

Quenching: Oil quench for maximum hardness (air quench may be suitable for thin sections)

Tempering: Temper at 150-370°C depending on desired hardness

Lower tempering temperatures (150-200°C): Maximum hardness (54-56 HRC)

Medium temperatures (230-300°C): Slightly lower hardness with improved toughness

Higher temperatures (350-370°C): Lower hardness but best toughness

Temperatures between 400-550°C should be avoided due to embrittlement

Double tempering is recommended for stress relief and dimensional stability

 

 

What are the welding considerations for 440A?
Welding 440A is not recommended for most applications due to its high carbon content and martensitic structure. If welding is necessary:

Preheating (250-350°C) is essential to prevent cracking

Low hydrogen welding processes are required

Austenitic filler metals (309L, 310L) are recommended

Post-weld heat treatment (tempering) is mandatory to restore properties

For critical applications, alternative grades with better weldability should be considered

 

Looking for a Reliable Supplier of 1.4117 / 440A Stainless Steel?
GNEE Steel supplies high-quality 440A (1.4117) stainless steel in bar, wire, strip, and plate forms, available in annealed condition for machining or pre-hardened to customer specifications. We provide full material certification (EN 10204 3.1) and processing support including precision cutting, grinding, and heat treatment services. If you have any requirements, please feel free to contact us.