Stud bolts · Heavy hex nuts · Hex bolts · SHCS · Washers · Threaded rod · PREN ≥ 40 · Hardness ≤ 28 HRC
The Zeron 100 fasteners catalog covers super duplex stainless steel fasteners (UNS S32760 / Werkstoff 1.4501) in every form needed for offshore, oil & gas, chemical, desalination, marine, FGD, and pulp & paper service. The 25Cr-7Ni-3.5Mo-0.7Cu-0.7W-0.25N composition delivers PREN ≥ 40 with the 50/50 austenite-ferrite microstructure that gives super duplex its 2×-316L yield strength + chloride-pitting + sour-service envelope. Solution-annealed (SA) Zeron 100 hits ASTM A479 minimums (550 MPa yield, 750 MPa UTS) and is satisfactory for most fastener applications. For applications requiring higher tensile properties: Zeron 100 FG meets ASTM A193 B7 mechanical envelope and the minimum Charpy impact toughness of 40 J at -50°C; Zeron 100 FLT meets ASTM A320 L7 cryogenic envelope. Both FG and FLT meet ASTM A276 S32760 Condition S.
| Fastener type | Standard | Use case |
|---|---|---|
| Stud bolts | ASTM A1082 + ASME B16.5 (double-end) | ANSI flange-class bolting (Class 150-2500); the workhorse of offshore + sour service |
| Heavy hex nuts | ASME B18.2.4.6M / ASTM A1082 | Stud-bolt companions; thicker pattern develops full A1082 stud yield |
| Hex bolts | ASTM A479 + ASME B18.2.1 | Standard hex-head bolts for short-grip applications |
| Heavy hex bolts | ASME B18.2.6 | Wider-AF / thicker-head pattern for high-clamp-load joints |
| Hex cap screws | ASME B18.2.1 (precision class) | Tapped-hole connections with precision bearing-face fit |
| Socket head cap screws (SHCS) | ASME B18.3 / ISO 4762 | Internal hex drive for tight-clearance counterbored installs |
| Hex nuts | ASME B18.2.2 | Standard hex pattern (vs heavy) for general bolting |
| Studs (continuous-thread) | ASTM A1082 | Tie-rods, anchor studs, through-bolted multi-member joints |
| Threaded rods | ASTM A1082 (rod stock) | Cut-to-length stud production stock; 1m / 3m / 6m metric, 36 in / 72 in inch |
| Washers | DIN 125 / 127 / 6796 / ASME F436 | Plain (load distribution), spring lock (vibration), Belleville (preload retention) |
| Countersunk screws (CSK) | ASME B18.6.3 | Flush-mount fasteners in machined countersinks |
| Set screws / grub screws | DIN 913 / 914 / 915 / 916 | Holding rotating elements on shafts |
| U-bolts | per buyer drawing | Pipe-clamp + tank-anchor U-shaped fasteners |
| 12-point flange screws | NAS / aerospace specs | High-torque internal-drive flange head, often for high-pressure aerospace + downhole |
| Push bolts / push rods | per buyer drawing | Custom super duplex bolting for special tooling |
| Alloy | PREN | Yield (MPa) | NACE compatible | Pick when |
|---|---|---|---|---|
| AISI 4140 (A193 B7) | 0 | 720 | B7M only | Dry indoor service, no corrosion |
| 304L stainless | 19 | 205 | limited | Mild atmospheric corrosion, low-load |
| 316L stainless | 26 | 205 | yes | Mild seawater splash; not immersion |
| Duplex 2205 (S31803) | 33-38 | 450 | yes | Moderate seawater + sour |
| Zeron 100 SA (S32760) | ≥ 40 | 620-720 | yes ≤ 28 HRC | Continuous seawater immersion + sour-service |
| Zeron 100 FG | ≥ 40 | 700-800 | yes ≤ 28 HRC | NORSOK + API 6A high-load + corrosion combined |
| Inconel 625 | 50 | 414 | yes | Above-300°C continuous service |
| Inconel 718 | 40 | 1100 | yes | Highest-strength + corrosion + high-temp; aerospace + downhole |
ASTM A1082 (super duplex stud / bolt / screw / threaded rod material spec) + ASTM A479 (source bar) + ASME B18.x (fastener-pattern dimensions) + ASME B1.1 / ISO 965 (thread tolerance class 2A / 6g) + NACE MR0175 / ISO 15156-3 (sour-service hardness limit ≤ 28 HRC) + NORSOK M-650 + M-630 MDS 055 (North Sea super duplex) + API 6A PSL3 / 6DSS / 17D / 20E BSL-3 (oil-gas + subsea) + EN 10269 (European pressure equipment) + MERKBLATT AD 2000 W2/W7/W10 (German pressure-vessel code).
Send the spec (fastener type + size + length + supply state SA / FG / FLT / AFP + standards / MDS to comply with + coating if any + quantity + destination port) to info@torqbolt.com or +91-22-66157017 / WhatsApp.
