Monel 400 Allen Screws Specification

Monel 400 Equivalent Designation
| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| N04400 | – | 2.4360 | Nicu30 | – | Qa 400 |
Monel 400 Allen screws are externally threaded fasteners typically driven into a tapped hole or self-tapped material. TorqBolt manufactures Monel 400 Allen screws per ASME B18.3 (socket products), ASME B18.6.3 (machine screws), DIN 912 / 7991 / 6912, and ISO 4762 / 10642, in metric M3–M48 and imperial 0–1/2".
Monel 400 Allen screws are available in cap (cylindrical), button (low-profile dome), countersunk / flat (82° or 90°), pan, fillister, truss, and shoulder configurations. Countersunk per DIN 7991 with 90° head angle is standard for metric; 82° per ASME B18.6.3 for imperial.
Monel 400 Allen screws use full-thread or partial-thread (length-under-head) configurations. Machine screws are typically full-thread; cap screws use partial thread for grip control. Threading per ASME B1.1 (UNC/UNF) or ISO 965 (metric coarse/fine), Class 2A or 6g default. Length-under-head is measured from the bearing surface for hex/cap, from the largest face for countersunk. Custom lengths quoted to drawing.
TorqBolt produces Monel 400 Allen set screws (cup-point, cone-point, dog-point, flat-point, hex-socket DIN 913/914/915/916), shoulder screws (precision-ground shoulder for pivot applications), and self-tapping screws (Type AB, Type 25). All certified per EN 10204 3.1 / 3.2 with optional NACE MR0175 sour-service compliance.
Monel alloys are 67% Ni / 33% Cu solid-solution alloys distinguished by uniform corrosion resistance in seawater, hydrofluoric acid, alkalis, and salt brines — environments where stainless steels fail by chloride pitting or copper-bearing alloys fail to alkalis. Monel was the first commercial nickel alloy and remains the default for offshore + chemical-processing fasteners requiring HF resistance.
Monel 400 (UNS N04400) is the base composition supplied in the as-annealed or hot-finished temper. Yield strength is moderate (~240 MPa min) but toughness extends to cryogenic service. Monel K-500 (N05500) adds Al + Ti for γ' precipitation hardening, raising yield to ~620 MPa after age hardening per AMS 4676 — the standard for high-strength shafting and fasteners in seawater. Monel R-405 is a free-machining variant.
Monel fasteners are produced per ASTM B164 (rod/bar) and supplied with EN 10204 3.1 / 3.2 certificates including stress-corrosion testing. Galvanic compatibility with copper-nickel piping makes Monel the natural mate for naval, desalination, and salt-evaporator service. NACE MR0175 sour-service compliance maintained when stress is below the SSC threshold for the specific heat-treat condition.