Titanium Grade 5 Acorn Nuts Specification

Titanium Grade 5 Equivalent Designation
| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| R56400 | Ta10-13/ta28 | 3.7165 | – | – | – |
Titanium Grade 5 Acorn nuts are internally threaded fasteners that mate with bolts and studs to form clamped joints. TorqBolt manufactures Titanium Grade 5 Acorn nuts per ASME B18.2.2, ISO 4032/4033/4034, DIN 934/EN 24032, and DIN 6915 (heavy hex), in sizes M6–M100 and 1/4"–4".
For vibration-loaded joints, Titanium Grade 5 Acorn nuts are available as nyloc (polymer insert), all-metal prevailing-torque (DIN 980, distorted-thread style), flange-serrated (DIN 6923, integral washer face with anti-back-off teeth), and castle / slotted (DIN 935, cotter-pin retention). Each locking style trades reusability against prevailing-torque retention.
Titanium Grade 5 Acorn nut threads are gauged per ASME B1.1 / ISO 965 to Class 2B / 6H by default; high-strength variants use 3B / 4H6H. Proof-load testing per ASTM F606 verifies the nut can develop the bolt's full strength without thread strip; hardness range is controlled to prevent stress-corrosion susceptibility (HV 250–353 typical for high-grade nuts). Each lot is EN 10204 3.1 / 3.2 certified.
TorqBolt also produces Titanium Grade 5 Acorn nuts in weld-nut, T-nut, square-nut, knurled thumb-nut, and rivet-nut patterns. NACE MR0175 / ISO 15156 sour-service certification available; NORSOK M-650 qualified mills supplying high-temperature service grades.
Titanium alloys deliver an exceptional strength-to-weight ratio (density ~4.5 g/cm³, half of steel) combined with outstanding seawater + chloride corrosion resistance — the spontaneously-formed TiO₂ surface film is impervious to chlorides and most oxidizing acids. Titanium is the default for marine offshore, desalination, chemical-process, and aerospace fasteners requiring weight reduction with corrosion immunity.
Grade 2 commercially-pure (CP-Ti) is the workhorse: yield ~275 MPa, fully formable, weldable, the standard for heat-exchanger tubing and chloride-service bolting. Grade 5 (Ti-6Al-4V) is the alpha-beta alloy delivering yield ~828 MPa after solution + age treatment per AMS 4928 / ASTM B348 — the dominant aerospace + medical grade. Grade 7 / Grade 11 add Pd for crevice + reducing-acid resistance. Grade 9 (Ti-3Al-2.5V) is the high-strength tubing alloy. Grade 12 (Ti-Mo-Ni) trades strength for hot-brine corrosion performance.
Titanium fasteners ship per ASTM B348 (Grade 2 / 5) and AMS 4928 / 4965 with EN 10204 3.1 / 3.2 certificates including hydrogen (≤ 125 ppm), oxygen, and tensile testing. Welding requires inert-gas shielding (back-purged Ar) to prevent embrittlement. NACE MR0175 sour-service is fully qualified across all common grades.