Stainless Steel Threaded Rod A2 A4 Marine DIN975 DIN976
Stainless Steel Threaded Rod — A2-70 / A4-80, DIN 975 / DIN 976, M6–M64
Thestainless steel threaded rod is a fully threaded fastening element used where standard hex bolts are too short — functioning as tie rods, hanger rods, anchor studs, pipe support rods, and structural tension members across marine piping, engine room, and deck equipment systems. Unlike a hex bolt with a fixed grip length, a threaded rod can be cut to any required length and secured with nuts on one or both ends, making it the universal adjustable-length fastening solution on ships.
sinofastener supplies stainless steel threaded rods in A2-70 (304),A4-70 (316), and A4-80 (316L, enhanced strength), covering metric sizes M6 through M64. Available in standard lengths per DIN 975 and DIN 976, or precision cut-to-length for shipboard installation without site-side waste.
DIN 975 vs DIN 976: Which Standard for Which Size
| Standard | Diameter Range | Standard Lengths | Thread Coverage |
|---|---|---|---|
| DIN 975 | M6 – M20 | 1000 mm | Threaded on one end (typically 1×D to 2×D unthreaded shank) |
| DIN 976 | M3 – M64 | 1000 mm / 2000 mm / 3000 mm | Fully threaded along entire length |
DIN 975 rods are used when one end is anchored (embedded in concrete, welded to structure, or fixed with a nut against a bearing surface) and only the protruding end requires threads. DIN 976 fully threaded rods allow nut positioning at any point along the length — essential for adjustable pipe hangers, tension tie rods, and applications where both ends require nut fixation.
A2-70 vs A4-70 vs A4-80: Material Selection for Marine Service
| Property | A2-70 (304) | A4-70 (316) | A4-80 (316L) |
|---|---|---|---|
| Steel Grade | AISI 304 / 1.4301 | AISI 316 / 1.4401 | AISI 316L / 1.4404 |
| Tensile Strength | ≥ 700 MPa | ≥ 700 MPa | ≥ 800 MPa |
| Yield Strength (Rp0.2) | ≥ 450 MPa | ≥ 450 MPa | ≥ 600 MPa |
| Molybdenum Content | None | 2.0–3.0% | 2.0–3.0% |
| PREN (Pitting Resistance) | ~18 | ~24 | ~24 |
| Chloride Resistance | Suitable for interior, low-humidity marine use | Required for seawater splash zone and ballast tank areas | Same chloride resistance as A4-70, with higher strength |
| Carbon Content | ≤ 0.07% | ≤ 0.07% | ≤ 0.03% (low carbon — resists sensitization after welding) |
| Best Marine Use | Accommodation HVAC hangers, interior duct rods, non-exposed equipment mounting | Engine room pipe hangers, deck equipment anchor studs, ballast system tie rods | High-preload tension rods, welded structural connections, vibration-critical pump mounting |
Why Stainless Threaded Rod Over Carbon Steel Alternatives
Carbon steel threaded rods rely on zinc plating or HDG coating for corrosion protection. In marine environments, these metallic coatings degrade progressively — zinc plating (96–200 hours salt spray) typically fails within 6–12 months in engine room humidity, and even HDG coatings require periodic inspection and touch-up on exposed deck installations. Stainless steel threaded rods eliminate this maintenance cycle — the chromium oxide passive layer provides inherent corrosion resistance without coating dependency, and in the case of A4-80, the low carbon content prevents chromium carbide precipitation at weld zones (sensitization).
Marine Applications by Grade
| Application | Recommended Grade | Environment |
|---|---|---|
| Engine Room Pipe Hanger Rod | A4-70 | High humidity + oil mist; continuous condensation cycle |
| Ballast Tank Tie Rod | A4-80 | Constant seawater immersion; chloride pitting risk |
| HVAC Duct Hanger (Accommodation) | A2-70 | Low-chloride interior; condensation from air conditioning |
| Deck Equipment Anchor Stud | A4-70 | UV + saltwater splash zone; no coating maintenance |
| Pump Base Mounting Stud | A4-80 | Vibration + chemical media; high preload retention |
| Hatch Coaming Reinforcement Rod | A4-70 | Exposed deck level; cyclic wet/dry weathering |
Threaded Rod vs Stud Bolt: When to Use Each
| Feature | Threaded Rod (DIN 975/976) | Stud Bolt (ASTM A193 B8/B8M) |
|---|---|---|
| Length Flexibility | Available in standard lengths, cut-to-length on site | Fixed length, manufactured to specific dimension |
| End Configuration | Can be nut-secured at any position along thread | Typically two nuts on fixed-length body |
| Primary Use | Adjustable hangers, tie rods, anchor studs, general assembly | Flange bolting in piping systems (Class 150–2500) |
| Standard | DIN 975 (single-end thread) / DIN 976 (full thread) | ASTM A193 B8M (metric: A193/A193M) |
| Marine Typical Application | Pipe hangers, equipment mounting, structural tie rods | Pipeline flange connections, pressure vessel bolting |
Supply Information
| Parameter | Specification |
|---|---|
| Diameter Range | M6 – M64 |
| Standard Lengths | 1000 mm (DIN 975) / 1000 mm, 2000 mm, 3000 mm (DIN 976) |
| Cut-to-Length Tolerance | ±1 mm; chamfered or plain cut ends available |
| Thread Form | Metric coarse (standard); metric fine or UNC/UNF on request |
| Surface Finish | Mill finish (as-drawn); electropolished or passivated per ASTM A967 on request |
| Certification | EN 10204 3.1 material certificate (heat number, chemical composition, mechanical test) |
sinofastener — 36 years of fastener manufacturing. Annual capacity 50,000 tonnes. Matching stainless steel hex nuts (DIN 934 / ISO 4032) and flat washers (DIN 125 / DIN 9021) available for complete corrosion-resistant assembly supply. Third-party inspection coordinated on request.
Material: A2-70 (304) / A4-70 (316) / A4-80 (316L)
Standard: DIN 975 (M6–M20, 1m) / DIN 976 (M3–M64, 1m/2m/3m)
Size Range: M6 – M64
Thread: Metric coarse, tolerance 6g
Finish: Mill finish; passivated or electropolished on request
E-mail: sales@sinofastener.com | SINOFASTENER
