Zeron 100 hex nuts are super duplex stainless steel finished hex nuts (UNS S32760 / Werkstoff 1.4501) per ASME B18.2.2 standard hex pattern (inch) or ISO 4032 (metric). Standard hex is the lighter of the two ASME nut patterns, thinner across the height and narrower across the flats than the heavy series, suitable for general-purpose fastening with hex bolts and threaded rod where joint loads are within the standard-hex thread-strip envelope. Heat-forged hot from solution-annealed bar, then SA + tapped to class 2B (inch) or 6H (metric).
Standard hex pattern (vs heavy) · PREN ≥ 40 · Hardness ≤ 28 HRC · SA / FLT supply states
For high-clamp-load applications, ASTM A1082 stud bolts, NORSOK M-650 topside flanges, API 6A wellhead bonnets, specify heavy hex nuts instead. The heavy pattern has more thread engagement and is sized to develop the full A1082 stud yield without thread strip-out, which standard hex cannot. Use this page (standard hex) for general bolting; use heavy-hex-nuts for primary load-path joints.
ASME B18.2.2 (inch standard hex nut) + ISO 4032 (metric standard hex nut) + ASTM A1082 (super duplex material) + ASTM A479 (source bar) + ASTM F606 / ISO 898-2 (proof-load test) + NACE MR0175 (sour service ≤ 28 HRC) + NORSOK M-650 + M-630 MDS 055.
| Series | Thread | Width across flats | Thickness |
|---|---|---|---|
| UNC inch | 1/4-20 to 1-1/2-6 | 7/16 in to 2-1/4 in | 7/32 in to 1-3/16 in |
| UNF inch | 1/4-28 to 1-1/2-12 | 7/16 in to 2-1/4 in | 7/32 in to 1-3/16 in |
| Metric coarse | M3 to M48 | 5.5 to 75 mm | 2.4 to 38 mm |
| Metric fine | M8 to M48 | 13 to 75 mm | 6.5 to 38 mm |
| Scenario | Standard hex (this page) | Heavy hex (other page) |
|---|---|---|
| Hex bolt & nut, general bolting | Yes, matched pattern | Overkill |
| ASTM A1082 stud bolt + nut on ANSI flange | Insufficient thread engagement | Yes, required pattern |
| NORSOK M-650 topside flange bolting | No, below buyer-spec | Yes, standard match |
| API 6A wellhead bonnet bolting | No | Yes |
| Equipment frame fasteners + bracket bolting | Yes | Available but unnecessary |
| Tie-rod end termination (non-flange) | Yes | Available but unnecessary |
Send the spec (thread + supply state + standards / MDS + coating + quantity + destination port) to info@torqbolt.com or +91-22-66157017 / WhatsApp.
