Fermonic 50 – Annealed (UNS S20910 XM-19)


Fermonic® 50 – Annealed is a nitrogen-strengthened austenitic stainless steel supplied in the annealed condition. It provides almost double the yield strength of common austenitic stainless steel grades such as Alloy 304 and Alloy 316L, offering the potential to reduce section size and therefore weight and cost. Higher strength can be achieved through cold working. Importantly, it remains fully austenitic – and therefore, fully non-magnetic – even after severe cold-working.

This product maintains excellent ductility and toughness at both elevated and cryogenic temperatures, combined with improved abrasion and erosion resistance relative to other austenitic stainless steel grades, making it a useful and cost-effective alloy in a wide range of demanding applications. It can generally be formed and welded in the same way as other 3xx alloys, although machining may require slower speeds / more power due to its high work hardening rate. It achieves corrosion resistance equivalent or better than Alloy 317L in a wide range of environments, and is listed in NACE MR 01 75 for sour service given its ability to resist sulphide stress cracking.

Key Features:

  • Higher strength and hardness than other austenitic stainless steels such as Alloy 304, Alloy 316L & Alloy 317L
  • Excellent ductility and toughness at both elevated and cryogenic temperatures
  • Non-magnetic, even after severe cold working, making it suitable for sensor applications
  • Excellent corrosion resistance, including resistance to chloride and sulphide stress cracking
  • Higher resistance to abrasion, erosion and cavitation erosion than Alloy 304, Alloy 316L & Alloy 317L austenitic stainless steels
  • Listed in food handling standards (FDA) as an acceptable material for food contact surfaces
  • Listed in MR-1075 for sour service oilfield applications


  • Oil & Gas industry downhole equipment
  • Marine pumps, valves, masts, tie downs, fixtures and fittings
  • Food processing equipment
  • Process industry equipment in sulphuric acid, nitric acid, polythionic acid, urea production, organic & fatty acids
  • Pulp and paper Industry valves and fittings

Chemical Composition:

Cr Ni Mo Co Nb (+Ta) Ti V W Cu C Mn N Si P S Fe Al
Min 20.50 11.50 1.50 0.10 0.10 4.00 0.20
Max 23.50 13.50 3.00 0.30 0.30 0.06 6.00 0.40 1.00 0.045 0.030 Bal

Mechanical Properties:

0.2% Proof Stress 380 N/mm2 55 ksi
Tensile Strength 690 N/mm2 100 ksi
Elongation, 5.65√S0 and 4D 35%
Reduction of Area 55%
Hardness (Brinell) 293 max.
Impact Strength (Room Temp) 54J av
Impact Strength (-60oC) 27J av (20J min)


  1. Testing shall be carried out in accordance with ASTM A370 or EN ISO 6892-1 (tensile), EN ISO 6506-1 (hardness)
  2. Minimum properties quoted (tested at room temperature in a longitudinal direction)
  3. Testing performed on each melt of material per heat treatment batch

Physical Properties:

Density (Kg/m3) 7880
Magnetic Permeability (20°C) <1.05
Young’s Modulus (kN/mm2) 197
Specific Electrical Resistance, 20°C (µΩ-m) 0.82
Mean coefficient of thermal expansion, 20-100°C (m/m/°C) 17.9 x 10-6
Specific Heat, 20°C (J/kg.K) 475
Thermal conductivity, 20°C (W/m.K) 13.3


Datasheet - S-Fermonic 50

Datasheet - S-Fermonic 50

Brochure - Fermonic 50 - Detailed product information

Brochure - Fermonic 50 - Detailed product information