A reason why the UNS S32750 Fasteners is well favoured amongst most of our clients is that they outperform several alloy steel as well as ferritic and austenitic stainless steel grades. This duplex alloy grade was designed with the intention of being used in extremely corrosive environments, especially those conditions where the application faces a roadblock, in the form of chlorine induced stress related corrosion cracking.

ASTM A479 UNS S32750 Bolts

ASTM A479 UNS S32750 Bolts

The ASTM A479 specified fasteners such as the UNS S32750 screw is supplied in the tempered, normalized, annealed, or quenched conditions, each specimen is to be tested. These tests to be carried out on the fastener ensures that the ASTM A479 UNS S32750 Bolts produced conform to the requirements mentioned in the specification. For e.g. - the fasteners are required to meet the requirements such as elongation, and hardness in addition to being checked for its tensile strength as well as yield strength properties.


The high chromium and molybdenum content present in the alloy is what makes the A479 Super Duplex Steel UNS S32750 Hex Nuts extremely resistant to uniform corrosion by organic acids like formic acid and acetic acid. Further, the S32750 super duplex stud bolt is an alloy that can provide excellent resistance to inorganic acids, especially those acidic solutions that contain chlorides. Unlike austenitic, stainless steel grade 316L, this dual microstructured Super duplex S32750 threaded rod could be used in dilute hydrochloric acid.

Super Duplex UNS S32750 Composition

Chemicals Content (%)
Sulfur, S 0.020 max
Chromium, Cr 24 – 26
Phosphorous, P 0.035 max
Carbon, C 0.030 max
Nickel, Ni 6 – 8
Molybdenum, Mo 3 – 5
Silicon, Si 0.80 max
Copper, Cu 0.50 max
Manganese, Mn 1.20 max
Nitrogen, N 0.24 – 0.32
Iron, Fe Balance

Mechanical Properties Table of S32750 super duplex stud bolt

Material Yield Strength
0.2% Proof (MPa) min
Tensile Strength
(MPa) min
Hardness
Rockwell C (HR C)
Elongation
(% in 50mm)
Alloy 32750 550 795 32max 15

Super duplex S32750 threaded rod Material Equivalent

Alloy European Common Name ASTM/ASME UNS
Alloy S32750 1.4410 SAF S32750 ® ASTM A479 S32750

Physical Properties of A479 Super Duplex Steel UNS S32750 Hex Nuts

Properties Imperial Metric
Density 0.281 lb/in3 7.8 g/cm3
Melting point 2460°F 1350°C

UNS S32750 Screw standard quality specification

Standard ASTM A479/ ASME SA479
Sizing 3/6 inch upto 2 inch | M3 – M56
Dimensional Standard : DIN 931, DIN934, DIN 933, 976, 7991, 125, ASME B18.3, B18.2.1
Lengths M02 to M152.4

Standard Dimensions of ASTM A479 UNS S32750 Bolts

Standard Dimensions of ASTM A479 UNS S32750 Bolts

Minimal Size (D) THE FLATS BODY DIAMETER HEAD THICKNESS CORNERS
F (MAX) F (MIN) D (MAX) D (MIN) H (MAX) H (MIN) C (MAX) C (MIN)
m10 17.00 15.73 10.00 9.78 6.63 6.17 18.48 17.77
m48 75.00 72.60 48.00 47.38 31.07 28.93 86.60 82.76
m100 145.00 140.00 90.00 99.13 63.9 60.10 167.43 159.60
m12 19.00 17.73 12.00 11.73 7.76 4.24 20.78 20.03
m14 22.00 20.67 14.00 13.73 9.09 8.51 24.25 23.35
m16 24.00 23.67 16.00 15.73 10.32 9.68 27.71 26.75
m20 30.00 29.16 20.00 19.67 12.88 12.12 34.64 32.95
m90 130.00 125.50 90.00 89.13 57.74 54.26 150.11 143.07
m24 36.00 35.00 24.00 23.67 15.44 14.56 41.57 39.55
m30 46.00 45.00 30.00 29.67 19.48 17.92 53.12 50.85
m80 115.00 111.00 80.00 79.26 51.58 48.42 132.72 126.54
m36 55.00 53.80 36.00 35.61 23.38 21.63 63.51 60.79
m42 65.00 62.90 42.00 41.38 26.97 25.03 75.06 71.71
m64 95.00 91.80 64.00 63.26 41.32 38.68 109.70 104.65
m56 85.00 82.20 56.00 55.26 36.2 33.80 98.15 93.71
m72 105.00 101.40 72.00 71.26 46.45 43.55 121.24 115.60