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400 Series Stainless

The 400 series group of stainless steels has an 11 percent chromium and 1-percent manganese increase, above the 300 series group. The 400 series is susceptible to rust and corrosion under some conditions. Heat-treating will harden the 400 series. The 400 series of stainless steels have higher carbon content, giving it a martensitic crystalline structure. This provides high strength and high wear resistance. Martensitic stainless steels aren’t as corrosion resistant as the austenitic types.

Product Forms

Penn Stainless stocks the following products in 400 Series stainless steel:

Stainless Steel 400 Series Products
Stainless Steel Plate Plate Mill Plate, Coil Plate More Information
Stainless Steel Sheet 2B/2D Finish, Polished Sheet, Perforated Sheet, Flat & Expanded More Information
Stainless Steel Bar Round Bar – Square Bar – Hex Bar – Rolled Flat – Sheared & Edged More Information
Stainless Steel Structural Some structural items may be available in 400 series stainless. Contact a sales associate for details. More Information
Stainless Steel Tubular Some tubular items may be available in 400 series stainless steels. Please contact a sales associate for details. More Information

Common Applications

The 400 series includes both ferritic and martensitic steels.

Ferritic steels: non-hardening steels,  ideal for conditions in elevated temperatures. Typical applications for ferritic stainless steels include petrochemical, automotive exhaust systems, heat exchanges, furnaces, appliances and food equipment to name a few.

Martensitic steels: able to be hardened, ideal for a wide variety of common uses. Martensitic stainless steels are used extensively in cutlery, sport knives and multi-purpose tools.

The table below shows common types of 400 series steel:

400 Series Applications
Type 405 a ferritic steel, used especially for welding applications
Type 408 heat-resistant; poor corrosion resistance; 11% chromium, 8% nickel.
Type 409 cheapest type; used for automobile exhausts; ferritic (iron/chromium only).
Type 410 martensitic (high-strength iron/chromium). Wear-resistant, but less corrosion-resistant.
Type 416 easy to machine due to additional sulfur
Type 420 Cutlery Grade martensitic; Excellent polishability.
Type 430 decorative steel, used for automotive trim; ferritic. Good formability, but with reduced temperature and corrosion resistance.
Type 440 a higher grade of cutlery steel, with more carbon in it, which allows for much better edge retention when the steel is heat-treated properly.
Type 446 For elevated temperature service

Advantages

Advantages and Characteristics of 400 Series Stainless Steel

Ferritic, or nonhardenable stainless steels, are classified in the 400 series. This series is known for:

  •  superior corrosion resistance
  • resistance to scaling at elevated temperatures
  • inherent strength greater than carbon steels
  • provide an advantage in many applications where thinner materials and reduced weight are necessary
  • nonhardenable by heat treating
  • always magnetic

Martensitic, or hardenable stainless steels, are classified in the 400 series. This series is known for:

  • higher levels of carbon than ferritics
  • ability to be heat treated to a wide range of hardness and strength levels
  • excellent corrosion resistance
  •  easily machined
  • good ductility

 

GradesDescription
403Penn Stainless inventory includes Alloy 403 (UNS S40300) in round bar thru re-certification of 410 stainless steel. Other product forms such as plate may also be available by re-certifying 410 stainless steel to meet the requirements of 403.More Information
405Penn Stainless inventory includes Alloy 405 (UNS S40500) in plate. Other product forms maybe available upon request.More Information
409Penn Stainless inventory now includes Alloy 409 (UNS S40900) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.More Information
410Penn Stainless inventory now includes Alloy 410 (UNS S41000) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.More Information
410SPenn Stainless inventory now includes Alloy 410S (UNS S41008) in sheet, plate and processed flat bar. Tubular products are available upon request.More Information
410HTPenn Stainless inventory now includes Alloy 410 HT (UNS S41000) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.More Information
416Penn Stainless inventory now includes Alloy 416 (UNS S41600) in plate and round bar products.More Information
416HTPenn Stainless inventory now includes Alloy 416HT (UNS S41600) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.More Information
420Penn Stainless inventory now includes Alloy 420 (UNS S42000) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.More Information
422Penn Stainless inventory now includes Alloy 422 (UNS S42200) in round bar.More Information
430Penn Stainless inventory now includes Alloy 430 (UNS S43000) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.More Information
440CPenn Stainless inventory now includes Alloy 440C (UNS S44000) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.More Information