Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
ASTM F468 - Monel 400 / UNS N04400 Nonferrous Bolts & Studs
ASTM F468/F468M is the governing standard for Monel 400 (UNS N04400) bolts, hex cap screws, socket head cap screws and studs. Class A (mechanical property marking F 468U) covers weldable nickel-copper alloy 400. Class B (F 468V) covers the free-machining variant alloy 405 (UNS N04405). The two classes share base chemistry; the only difference is sulphur: 0.024 max for Class A versus 0.025 to 0.060 for Class B. Monel® is a registered trademark of Special Metals Corporation; TorqBolt is not authorized by, affiliated with or endorsed by Special Metals.
F468 Product Envelope and Size Range
F468 covers bolts, hex cap screws and studs from 1/4 in to 1-1/2 in nominal thread diameter, with socket head cap screws extending down to size 0 (0.060 in). The F468M metric companion covers M6 to M40. Hex dimensions follow ASME B18.2.1, socket head cap screws follow ASME B18.3, threads are Class 2A per ASME B1.1 by default. The most common TorqBolt orders are 1/2 in through 1-1/4 in hex cap screws and stud bolts in 2 in to 12 in lengths with matching ASTM F467 nuts from the same heat.
Class A (F 468U) vs Class B (F 468V) for Monel 400
| Attribute | Class A (F 468U) - Ni 400 | Class B (F 468V) - Ni 405 |
|---|---|---|
| UNS designation | N04400 | N04405 |
| Nickel | 63.0 - 70.0 % | 63.0 - 70.0 % |
| Copper | Balance | Balance |
| Iron, max | 2.5 % | 2.5 % |
| Manganese, max | 2.0 % | 2.0 % |
| Carbon, max | 0.3 % | 0.3 % |
| Silicon, max | 0.5 % | 0.5 % |
| Sulphur | 0.024 max | 0.025 - 0.060 (intentional) |
| Weldability | Weldable (standard grade) | Not recommended for welded service |
| Machinability | Standard | Free-machining (sulphide chip breaker) |
| Default selection | Pressure boundary, sour service, NORSOK M-650 | High-volume machined fasteners, no welding |
Class A is the default for piping, pressure vessels and sour service. Class B is selected only when chip-break machinability governs. If the procurement specification does not call out Class B, assume Class A.
F468 Mechanical Minima for Monel 400
F468 Table 2 sets the mechanical floors. The Monel 400 entries are size-banded for Class A, quoted directly from Table 2 below.
| Marking | Alloy / Class | Diameter | Tensile, ksi | Yield, min ksi | Hardness | Elong. 4D, min |
|---|---|---|---|---|---|---|
| F 468U | Ni 400 Class A | 0.250 - 0.750 in | 80 - 130 | 40 | 75 HRB - 25 HRC | 20 % |
| F 468U | Ni 400 Class A | 0.875 - 1.500 in | 70 - 130 | 30 | 60 HRB - 25 HRC | 20 % |
| F 468U4 | Ni 400 Class A (uprated) | 0.875 - 1.500 in | 80 - 130 | 40 | 75 HRB - 25 HRC | 20 % |
| F 468HF | Ni 400 hot-formed | All | 70 - 120 | 30 | 60 - 95 HRB | 20 % |
| F 468V | Ni 405 Class B | All | 70 - 125 | 30 | 60 HRB - 20 HRC | 20 % |
Every F468 Monel 400 marking caps hardness at 25 HRC (20 HRC for F 468V). For 0.875 in and larger, the standard F 468U yield is 30 ksi; F 468U4 is the optional uprated marking that holds 40 ksi yield across the full range. Specify F 468U4 explicitly when joint design relies on the 40 ksi floor in larger sizes.
Marking Codes and Heat Documentation
Every F468 fastener 1/4 in and larger carries the manufacturer symbol plus the property code from Table 2: F 468U, F 468U4, F 468HF or F 468V for Monel 400. Supplementary Requirement S4 (heat control for alloys 400, 405 and 500) produces a fully heat-traceable lot and invokes S2 automatically. Together they yield an EN 10204 3.1 (or 3.2 on request) MTC with heat chemistry plus tensile and hardness data per lot. TorqBolt supplies Monel 400 bolts under S4 + S2 by default.
NACE MR0175 / ISO 15156 Cross-Reference
NACE MR0175 / ISO 15156-3 lists UNS N04400 as acceptable for sour service at 35 HRC maximum. F468 caps Class A Monel 400 at 25 HRC, 10 HRC tighter than NACE, so any F 468U or F 468U4 bolt is automatically inside the NACE envelope. Standard sour-service practice is F468 bolt, F467 nut, NACE MR0175 compliance on the MTC and EN 10204 3.1 or 3.2 certification.
Related Monel 400 Standards and Fastener Pages
- Monel 400 bolts - product landing for the F468 family
- Monel 400 stud bolts - double-end studs to F468 mechanicals
- Monel 400 hex bolts - ASME B18.2.1 dimensional
- ASTM F467 - matching nonferrous nuts, the F468 companion
- NACE MR0175 / ISO 15156 - sour service compliance
- ASTM B164 - Monel 400 rod and bar starting stock
- UNS N04400 - alloy designation reference
Frequently Asked Questions
What is the difference between F 468U and F 468V?
F 468U is Monel 400 Class A (UNS N04400) with sulphur 0.024 percent maximum and standard weldability. F 468V is Class B (UNS N04405) with sulphur 0.025 to 0.060 percent for free-machining service. Class A is the default; Class B is chosen only when machinability governs.
What are the F468 mechanical minima for Monel 400?
F 468U at 0.250 to 0.750 in must develop 80 to 130 ksi tensile, 40 ksi yield and 20 percent elongation in 4D. From 0.875 to 1.500 in, standard F 468U yield drops to 30 ksi; F 468U4 holds 40 ksi yield across the full range. Hardness is capped at 25 HRC throughout.
Are F468 Monel 400 bolts acceptable under NACE MR0175?
Yes. NACE MR0175 / ISO 15156-3 accepts UNS N04400 at 35 HRC maximum. F468 caps Monel 400 at 25 HRC, 10 HRC tighter, so F 468U product is automatically inside the NACE envelope.
What pairs with F468 for the matching nuts?
ASTM F467 / F467M is the companion specification for nonferrous nuts. Standard sour-service practice is F468 bolt with F467 nut, both ordered from the same heat.
Request a Quote
For ASTM F468 Monel 400 bolts (UNS N04400) pricing, mill heats on the floor, lead time and certification contact info@torqbolt.com or WhatsApp +91-22-66157017. Mumbai head office and Rajkot production plant. Worldwide export through JNPT and Mundra. Full Monel 400 alloy reference on the main page.
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