Being one of the most popular super duplex alloy grades in the market, the A182 F51 Bolts are predominantly used in industries such as hydropower, oil & gas, pressure vessels, structural components and chemical tankers, as well as the pulp & paper industry. A common problem that occurs in these industries is stress cracking. The dual microstructure in combination with the chemistry of the Super Duplex Gr F51 Screws is designed to combat stress related corrosion cracking in most environments. However, this is a property noticed even when the alloy has been exposed to halide containing environments, where the solution contains halogens like chlorine.

A182 F51 Bolts

A182 F51 Bolts

Along with offering high mechanical strength and toughness, the Super duplex f51 threaded rod is not only resilient to general corrosion but also to pitting and crevice corrosion. The significant content of elements chromium, molybdenum and nitrogen is what provides the UNS S31803 Stud with good resistance of 2205 to chloride pitting and crevice corrosion, especially in marine environments and brackish water, along with closed loop water systems as well as some food processing applications.


This is why the DIN 1.4462 Hex Bolt is often used to build components pertaining to the marine engineering industry. Although the ASTM A182 f51 super duplex Nut can be used at elevated temperatures, using this alloy for an extended period of time at temperatures over 600° F can cause embrittlement.

Specification list of A182 F51 Bolts

Standard ASTM A182/ ASME SA182
Sizing 3/6 inch upto 2 inch | M3 – M56
Lengths M02 to M152.4

Mechanical Analysis of DIN 1.4462 Hex Bolt

Product Tensile Strength
(MPa) min
Yield Strength
0.2% Proof (MPa) min
Elongation
(% in 50mm)
Hardness
Rockwell C (HR C)
Alloy Gr F51 105 43 35 255

UNS S31803 Stud Chemical Compatibility

Chemical Content (%)
Manganese, Mn 2.0 Max
Chromium, Cr 21 - 23
Carbon, C 0.03 max
Sulfur, S 0.02 Max
Copper, Cu Balance
Nickel, Ni 4.5 - 6.5
Molybdenum, Mo 2.5 - 3.5
Silicon, Si 1 Max
Nitrogen, N 0.80 - 0.20
Phosphorous, P 0.03 Max
Iron, Fe Balance

ASTM A182 F51 super duplex Nut Size Chart

Sizes of Nuts
(Millimetre)
Dia.*
(Millimetre)
Height
(Millimetre)
Hex Nut Jam Nut Nylock Nut
2 4 1.6 1.2 -
2.5 5 2 1.6 -
3 5.5 2.4 1.8 4
4 7 3.2 2.2 5
5 8 4 2.7 5
6 10 5 3.2 6
7 11 5.5 3.5 -
8 13 6.5 4 8
10 17 8 5 10
12 19 10 6 12
14 22 11 7 14
16 24 13 8 16
18 27 15 9 18.5
20 30 16 10 20