• View PDF
    Standard
  •   0091-22-66157017
  •   info@torqbolt.com
    • Home
    2. ASTM F467 Grade N06686

    ASTM F467/F467M Grade N06686 Alloy 686 Nuts Specification

    Premium nickel alloy nuts designed for extreme corrosion resistance.

    ASTM F467/F467M Grade N06686 Alloy 686 Nuts offer superior resistance against oxidation, pitting, and aggressive chemical environments in marine and industrial sectors.

    ASTM F467/F467M Chemical Composition

    ASTM F467/F467M Nickel and Nickel-Base Alloys

    UNS Designation Number Alloy General Name Al C, max Cr Cu A Fe, max Mn, max Ni A P, max Si, max Ti Co, max Mo S, max V W Cb †
    ASTM F467/F467M Grade N06686 686 Ni-Cr-Mo-W . . . 0.010 max 19.0- 23.0 . . . 5.0 max 0.75 max balance 0.040 max 0.08 max 0.02- 0.25 . . . 15.0- 17.0 0.02 max . . . 3.0- 4.4 . . .
    • (A) Elements shown as balance shall be arithmetically computed by deducting the sum of the other named elements from 100.
    • (B) Cobalt is to be counted as nickel.

    ASTM F467/F467M Mechanical Requirements

    ASTM F467/F467M Mechanical Requirements (Inch)

    Alloy Mechanical Property Marking Hardness, min A Proof Stress, Hex Nut min, ksi Proof Stress, Heavy Hex Nut min, ksi B
    ASTM F467 Alloy Ni 686 Grade 1 F 467BN 21 HRC 120 130
    ASTM F467 Alloy Ni 686 Grade 2 F 467CN 23 HRC 135 146
    ASTM F467 Alloy Ni 686 Grade 3 F 467DN 25 HRC 160 173
    ASTM F467 Alloy Ni 686 Grade 4 F 467EN 65 HRB-25HRC 100 108
    • (B) Proof stress values for heavy hex nuts are based on 1.08 times the value for corresponding regular hex nuts.

    ASTM F467M Mechanical Requirements (Metric)

    Alloy Mechanical Property Marking Hardness, min A Proof Stress, Mpa
    ASTM F467M Ni 686 Grade 1 F 467MBN 21 HRC 825
    ASTM F467M Ni 686 Grade 2 F 467MCN 23 HRC 930
    ASTM F467M Ni 686 Grade 3 F 467MDN 25 HRC 1100
    ASTM F467M Ni 686 Grade 4 F 467MEN 65 HRB-25 HRC 690

    ASTM F467/F467M Tensile Stress Areas and Threads per Inch

    Nominal Size, in. Coarse Threads-UNC Fine Threads-UNF 8 Thread Series-8UN
    Threads/in. Stress Area A, in 2 Threads/in. Stress Area A, in 2 Threads/in. Stress Area A, in 2
    1/ 4 20 0.0318 28 0.0364 . . . . . .
    5/ 16 18 0.0524 24 0.0580 . . . . . .
    3/ 8 16 0.0775 24 0.0878 . . . . . .
    7/ 16 14 0.1063 20 0.1187 . . . . . .
    1/ 2 13 0.1419 20 0.1599 . . . . . .
    9/ 16 12 0.1820 18 0.2030 . . . . . .
    5/ 8 11 0.2260 18 0.2560 . . . . . .
    3/ 4 10 0.3340 16 0.3730 . . . . . .
    7/ 8 9 0.4620 14 0.5090 . . . . . .
    1 8 0.6060 12 0.6630 . . . . . .
    1 1/ 8 7 0.7630 12 0.8560 8 0.790
    1 1/ 4 7 0.9690 12 1.0730 8 1.000
    1 3/ 8 6 1.1550 12 1.3150 8 1.233
    1 1/ 2 6 1.4050 12 1.5810 8 1.492
    • (A) Tensile stress areas are computed using the following formula:
    • A s = 0.7854 [ D - 0.9743/n ]
      • where:
      • As = tensile stress area, in. 2 ,
      • D = nominal size (basic major diameter), in., and
      • n = number of threads per inch.

    ASTM F467/F467M Tensile Stress Areas and Threads per Metric

    Nominal Nut Diameter and Thread Pitch Stress Area, Amm 2 Nominal Nut Diameter and Thread Pitch Stress Area, Amm 2
    M6 × 1 20.1 M16 × 2 157
    M8 × 1.25 36.6 M20 × 2.5 245
    M10 × 1.5 58.0 M24 × 3 353
    M12 × 1.75 84.3 M30 × 3.5 561
    M14 × 2 115 M36 × 4 817
    • (A) Tensile stress areas are computed using the following formula:
    • As = 0.7854 (D − 0.9382P) 2
      • where:
      • As = tensile stress area, mm. 2 ,
      • D = nominal size (basic major diameter), mm., and
      • n = number of threads per mm.

    ASTM F467/F467M Heat Treatment

    Alloy Condition
    Copper (all alloys) As formed or stress relieved at manufacturer's option
    Nickel alloys 400 and 405 As formed or stress relieved at manufacturer's option
    Nickel alloy 500 Solution annealed and aged
    Aluminum alloy 2024-T4 Solution treated and naturally aged
    Aluminum alloy 6061-T6 Solution treated and artificially aged
    Aluminum alloy 6262-T9 Solution treated, artificially aged, and cold worked
    Titanium 625 Annealed

    Frequently Asked Questions

    What is Alloy 686 (N06686)?

    Alloy 686 is a Ni-Cr-Mo-W alloy (~58 Ni, 20.5 Cr, 16.3 Mo, 3.9 W) - effectively an enhanced C-276 with more chromium for improved oxidizing-acid resistance while retaining tungsten for localized-corrosion protection. Per ASTM F467 for the most severe chemical-process nut and FGD scrubber applications.

    How does Alloy 686 compare to Hastelloy C-276?

    Alloy 686 has ~5% more Cr (20.5 vs 15.5) for better oxidizing-acid + hot-chloride resistance, with the same Mo + W giving it equivalent reducing-acid + pitting performance. Use 686 in mixed-chemistry service that defeats C-276; both are F467-covered.

    Is Alloy 686 NACE MR0175 acceptable?

    Yes. N06686 is listed in NACE MR0175 / ISO 15156 for sour-service nut subject to standard hardness and condition requirements.

    Where is Alloy 686 used in fastener applications?

    FGD scrubber bolting, hazardous-waste incinerator hardware, chlorine + chlorine-dioxide bleach plant fasteners, and high-temperature concentrated-acid process equipment. Pairs with Alloy 686 nuts per ASTM F467 for matched-alloy assemblies.

    References & Standards

    • ASTM F467 / F467M - Standard Specification for Nonferrous Nuts for General Use
    • ASTM F468 / F468M - Companion specification for Nonferrous Bolts, Hex Cap Screws, and Studs (mate with F467 nuts for matched-alloy assemblies)
    • ASTM F436 / F436M - Hardened steel washers (ferrous washer companion when nonferrous washers are not specified)
    • NACE MR0175 / ISO 15156 - Sour-service hardness limits for petroleum and natural gas industries
    • ASME B18.2.2 / B18.2.4.1M / B18.2.4.6M and ISO 4032 / 4033 / 4035 - Dimensional standards referenced by F467
    • DIN 934 / 439 / 6330 - Metric hex nut dimensional standards
    Questions? Contact us.
    Showcase of our Microsites.
    Satisfaction Survey

    survey

    TUVRheinland CERTIFIED

    © TorqBolt P(Ltd) · Built with in INDIA.