KVA Martensitic Stainless Steel (MSS) tube and pipe are low-cost, high performance substitutes for traditional carbon & stainless steels, titanium and 12Cr & 13Cr materials.
KVA MSS™ is the patented, original and only fully martensitic, high toughness seam-welded tube, offering unsurpassed tensile strength, hardness and wear resistance.
KVA longitudinal seam-welded MSS™ can be produced fully hardened, fully annealed, or anywhere in between, at substantial cost savings over seamless type 410 or type 420 tubing. Typical properties of KVA MSS (UNS S41000):

Typical properties of KVA MSS (UNS S41000):
Hardened:
- Yield strength: 160 ksi (1100 MPa)
- Ultimate tensile strength: 205 ksi (1400 MPa)
- Hardness: 370-390 Brinell (40-42C Rockwell )
- Elongation: 8-9%
Annealed:
- Yield strength: 45 ksi (300 MPa)
- Ultimate tensile strength: 80 ksi (530 MPa)
- Hardness: 130 Brinell (80B Rockwell )
- Elongation: 30+%
It is important to note that KVA seam-weld technology effectively reduces the hardness of the weld, in both the fusion zone and the heat-affected zone. This reduction in hardness, and associated improvements in ductility, toughness and formability, allows air-hardenable martensitic stainless steels to be used in welded applications historically considered impractical.
In addition, KVA seam-weld technology does not limit the part from fully transforming into a homogenous, uniform microstructure after a solution heat-treatment. The base metal, heat affected zone and fusion zone all reach uniform properties after hardening.
KVA Martensitic Stainless Steel tubing is proudly Made in the U.S.A. and is produced in our state-of-the-art tubemaking facility in southern California. The following charts list our current size range capabilities:
Secondary Process Engineering & Services:
- Annealing
- OD Finishing
- Tube Marking
- Cut To Length
- Cold Drawing*
- Heat Treating*
- Bending*
KVA MSS™ can be produced in lengths up to 30’ in the following standards:
- ASTM A249, A268, A1016, A554, A999
- ASME SA 249, SA 268, SA269,