ASTM B446 Specification

Forgings, Fasteners, Boltings, Stud Bolts, Screws, Nuts

Scope

ASTM B446 specification covers nickel-chromium molybdenum-columbium (UNS N06625), nickel-chromium molybdenum-silicon alloy (UNS N06219), and NickelChromium-Molybdenum-Tungsten Alloy (UNS N06650)1 in the form of hot-worked rod and bar and cold-worked rod in the conditions.
UNS N06625 products are furnished in two grades with respect to different heat-treated conditions:
Grade 1 (Annealed)-Material is normally employed in service temperatures up to 1100°F (593°C).
Grade 2 (Solution Annealed)-Material is normally employed in service temperatures above 1100°F (593°C) when resistance to creep and rupture is required.
NOTE 1-Hot-working or reannealing may change properties significantly, depending on working history and temperatures.
Alloys UNS N06219 and UNS N06650 are supplied in solution annealed condition only.

Related Specifications of ASTM B446 Bolting

ASTM B446 Chemical Composition

Composition Limits, % Element
UNS C Mn Si P S Cr Nb + Ta S (if determined) Mo Fe Al Ti Cu Ni A W N
N06625 0.10 max 0.50 max 0.50 max 0.015 max 0.015 max 20.0 min 23.0 max 3.15 min 4.15 max 1.0 max 8.0 min 10.0 max 5.0 max 0.40 max 0.40 max ... 58.0 min ... ...
N06219 0.05 max 0.50 max 0.70-1.10 0.020 max 0.010 max 18.0-22.0 ... ... ... 1.0 max 7.0-9.0 ... 2.0-4.0 0.50 max 0.50 max 0.50 max Bal. ... ...
N06650 0.03 max 0.50 max 0.50 max 0.020 max 0.010 max 19.0-21.0 ... 0.05-0.50   1.0 max 9.5-12.5 ... 12.0-16.0 0.05-0.50 ... 0.30 max Bal. 0.50-2.50 0.05-0.20
  • A Element shall be determined arithmetically by difference.

ASTM B446 Mechanical Requirements

UNS Diameter or Distance
Between Parallel Surfaces,
in. (mm)
Tensile Strength min,
ksi (MPa)
Yield Strength
(0.2 % offset), min,
ksi (MPa)
Elongation in
2 in. or 50 mm or
4D, min, %
UNS N06625 Grade 1 (Annealed) B Up to 4 (102), incl 120 60 30
Over 4 (102) to 10 (254), incl 110 50 25
UNS N06625 Grade 2 (Solution Annealed) C All sizes 100 40 30
UNS N06219 All (Solution Annealed) All sizes 96 (660) † 39 (270) 50
UNS N06650 All (Solution Annealed) All sizes 116 (800) 58 (400) 45
  • A Forging quality is furnished to chemical requirements and surface inspection only. No tensile properties are required. Forging stock is typically supplied in the hot worked condition, (see X1.1.5).
    B Annealed 1600°F (871°C) minimum.
    C Solution annealed at 2000°F (1093°C) minimum, with or without subsequent stabilization anneal at 1800°F (982°C) minimum to increase resistance to sensitization.

ASTM B446 Bolting Certifications

  • EN 10204 3.1
  • EN 10204 3.2
  • PED 2014/68/EC
  • MERKBLATT AD 2000 W2/W7/W10
  • API 20 E BSL 1/ BSL 2
  • NACE MR 0175
  • NACE MR 0103