INCONEL 718 NUTS - UNS N07718 / W.NR. 2.4668
■ ASME B18.2.2 Heavy Hex Nuts (Imperial)
| NOMINAL SIZE |
THREADS PER INCH (UNC) |
WIDTH ACROSS FLATS (Basic) |
THICKNESS (Basic) |
APPROX. WEIGHT (lbs/100 pcs) |
| 1/4" | 20 | 1/2" | 15/64" | 1.16 |
| 5/16" | 18 | 9/16" | 19/64" | 1.88 |
| 3/8" | 16 | 11/16" | 23/64" | 2.82 |
| 1/2" | 13 | 7/8" | 31/64" | 6.54 |
| 5/8" | 11 | 1-1/16" | 39/64" | 11.90 |
| 3/4" | 10 | 1-1/4" | 47/64" | 19.30 |
| 7/8" | 9 | 1-7/16" | 55/64" | 29.70 |
| 1" | 8 | 1-5/8" | 63/64" | 42.50 |
| 1-1/4" | 7 | 2" | 1-7/32" | 78.60 |
| 1-1/2" | 6 | 2-3/8" | 1-15/32" | 131.00 |
Engineering Note: In the imperial system (especially within the oil and gas sector), Heavy Hex Nuts are universally preferred. The wider dimension across the flats provides a larger bearing surface area to safely distribute the massive 150 ksi clamp load generated by Inconel 718 bolts.
■ DIN 934 / ISO 4032 Metric Hex Nuts (mm)
| NOMINAL THREAD SIZE |
PITCH (mm) |
WIDTH ACROSS FLATS (S max) |
NUT HEIGHT (M max) |
APPROX. WEIGHT (kg/1000 pcs) |
| M6 | 1.00 | 10.00 | 5.20 | 2.50 |
| M8 | 1.25 | 13.00 | 6.80 | 5.20 |
| M10 | 1.50 | 16.00 | 8.40 | 11.60 |
| M12 | 1.75 | 18.00 | 10.80 | 17.30 |
| M16 | 2.00 | 24.00 | 14.80 | 33.30 |
| M20 | 2.50 | 30.00 | 18.00 | 64.40 |
| M24 | 3.00 | 36.00 | 21.50 | 110.00 |
| M30 | 3.50 | 46.00 | 25.60 | 223.00 |
| M36 | 4.00 | 55.00 | 31.00 | 393.00 |
■ Nut-Specific Technical Specifications
| MATERIAL & SPECIFICATIONS |
Inconel 718 (UNS N07718). Governed primarily by ASTM A1014 and ASTM B637 for high-temperature bolting applications. Provides exceptional creep-rupture strength up to 1300°F (700°C). |
| MECHANICAL INTEGRITY |
When fully precipitation age-hardened:
- Ultimate Tensile Strength (Min): 185 ksi (1275 MPa)
- Yield Strength 0.2% Offset (Min): 150 ksi (1035 MPa)
- Hardness: 36 to 44 HRC (331 to 444 HBW)
|
| NACE MR0175 COMPLIANCE |
For oil & gas applications involving sour gas (H2S), Inconel 718 nuts must resist hydrogen embrittlement. To comply with NACE MR0175 / ISO 15156, the hardness of the nuts is strictly capped at a maximum of 40 HRC, requiring a modified heat treatment process. |
| TRIBOLOGY & SILVER PLATING |
Inconel 718 has a high friction coefficient, making bare nuts highly susceptible to thread galling (cold-welding) under extreme pressure. Nuts are routinely electroplated with silver according to the AMS 2410 specification. The silver acts as a high-temperature solid-film lubricant up to 1200°F (650°C) to prevent seizure and ensure a predictable K-factor during assembly. |
