CORROSION-CRITICAL HARDWARE · SPECIFICATION-LED SOURCING
Special Marine Fasteners
RFQ-led sourcing of bolts, nuts, screws, studs, threaded rod and washers in specified stainless, duplex, super-duplex and nickel-alloy material families.
MNK-G.S.A coordinates fastener inquiries for marine equipment, seawater systems, ship repair and industrial projects by exact standard, property class, material, dimensions, environment and documentation requirements.
Technical Identity
- A fastener designation combines finished-product standard, geometry, thread system, material grade, condition and mechanical property class. A raw bar certificate alone does not prove finished-fastener compliance.
- ISO 3506-1:2020 covers corrosion-resistant stainless-steel bolts, screws and studs and includes austenitic, martensitic, ferritic and duplex grades. ISO 3506-2:2020 covers nuts.
- ISO 3506-6:2020 provides material-selection rules for the ISO 3506 family and includes stainless-steel, duplex and nickel-alloy fastener materials.
- ASTM F593-24 and F594-24 cover specified stainless-steel bolt, stud and nut families for general corrosion-resistance service. ASTM F468-23(2026) and F467-24(2026) provide nonferrous fastener frameworks.
- Neither A4/316 nor any other familiar material label is universal approval for permanent immersion, crevices, warm chlorides, high preload or a galvanically dissimilar assembly.
Standards and Supply Scope
| Externally threaded fasteners | Bolts, cap screws, screws, studs and threaded rod against the specified finished-product and dimensional standard |
| Internally threaded fasteners | Nuts matched by thread system, material family, proof load or property class and governing standard |
| Washers and special parts | Plain, spring, locking or drawing-based parts under separate dimensional, material and functional requirements |
| ISO stainless framework | ISO 3506-1:2020, ISO 3506-2:2020 and ISO 3506-6:2020 |
| ASTM frameworks | ASTM F593-24 / F594-24 for listed stainless families; ASTM F468-23(2026) / F467-24(2026) for listed nonferrous families |
| Supply route | Standard catalogue items, made-to-order dimensions or parts manufactured to drawing, subject to verified capability |
Application Context
Potential marine contexts include deck machinery, pumps, valves, piping supports, seawater systems, access structures and repair assemblies. Final material selection must consider chloride exposure, temperature, immersion, crevices, galvanic coupling, galling, fatigue, preload, coating compatibility and access for inspection. The page does not replace class rules or bolted-joint engineering.
RFQ and Quality Controls
- Finished-fastener standard, drawing and dimensional standard
- Metric or inch thread, diameter, pitch, length, fit and head or nut style
- Exact alloy, heat-treatment condition and required property class
- Service environment, temperature, immersion, galvanic couples and coating system
- Preload, torque, locking, galling-control and assembly requirements where applicable
- Certificate type, lot traceability, testing, marking, inspection, quantity and destination
Related Technical Pages
Technical Sources
- ISO 3506-1:2020 — Stainless Steel Bolts, Screws and Studs
- ISO 3506-2:2020 — Stainless Steel Nuts
- ISO 3506-6:2020 — Fastener Material Selection
- ASTM F593-24 — Stainless Steel Bolts, Cap Screws and Studs
- ASTM F594-24 — Stainless Steel Nuts
- ASTM F468-23(2026) — Nonferrous Bolts, Cap Screws and Studs
- ASTM F467-24(2026) — Nonferrous Nuts
The cited standards cover defined fastener families and conditions. They do not prove suitability for every marine environment or every alloy requested. MNK verifies finished-product scope, grade, property class, testing and manufacturer documentation for each quotation.
Bolting for Pressure and Temperature Service
For pressure, high-temperature or low-temperature assemblies, define the equipment code, service conditions, bolting and nut specifications, grade/class pairing, impact or supplementary tests, coating and inspection documents.
- ASTM A193/A193M-26 — High-Temperature and High-Pressure Bolting
- ASTM A194/A194M-26 — Nuts for High-Pressure and High-Temperature Service
- ASTM A320/A320M-26 — Low-Temperature Bolting
- ASTM A962/A962M-26 — Common Requirements for Bolting
- EN 10269:2013 — Steels and Nickel Alloys for Temperature-Service Fasteners
Send Your Technical Inquiry
Send the finished-fastener standard or drawing, material grade and property class, thread system, dimensions, quantity, service environment, coating or locking requirements, documentation and delivery destination.
Special-Purpose Bolting References
These specifications address defined special-purpose routes; material, grade, class, service conditions and finished-lot documentation must be stated in the inquiry.