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FULLERKREG DIN 7967 PAL nuts in A4 marine-grade stainless steel (SUS316) are thin all-metal self-locking counter nuts featuring a unique radial-slot spring-action locking mechanism. The nut body is slotted through, and the two halves are offset during manufacture so that when tightened onto a bolt, the spring tension of the steel grips the thread flanks and resists loosening under vibration and dynamic loads. SUS316 (A4) adds molybdenum to the alloy, delivering superior resistance to chloride-induced pitting and crevice corrosion compared to A2 — making these nuts the preferred choice for marine, offshore, chemical processing, and coastal infrastructure applications. Bright-finished and passivated for maximum corrosion resistance.
| Standard | DIN 7967 |
| Common Name | PAL Nut · Self-Locking Counter Nut · Spring Nut |
| Material | SUS316 Marine Stainless Steel (A4) |
| Surface Treatment | Bright Finish + Passivation (洗白钝化) |
| Locking Mechanism | All-Metal Spring Action (radial slot + thread offset between two halves) |
| Thread | Metric Coarse Thread (ISO 68-1) |
| Size Range | M4 – M52 (Series 1 standard range; Series 2 & 3 for fine pitch) |
| Drive Type | Hex (Wrench / Spanner) |
| Nut Profile | Thin / Low Profile (Counter Nut) |
| Reusability | Good — all-metal, no nylon insert to degrade |
| Max Operating Temp. | Up to +300 °C (no nylon insert limitation) |
| Corrosion Resistance | Excellent — SUS316 with Mo addition; superior chloride & pitting resistance vs. A2 |
| Key Alloying Element | Molybdenum (Mo) 2–3% — enhances resistance to chloride pitting & crevice corrosion |
| Property | A4 — SUS316 (This Product) | A2 — SUS304 |
|---|---|---|
| Molybdenum Content | 2–3% Mo | None |
| Chloride Resistance | Excellent (marine / seawater) | Good (general environments) |
| Pitting Resistance (PRE) | ~25 | ~18 |
| Crevice Corrosion | Superior resistance | Moderate resistance |
| Acid Resistance | Better (esp. sulfuric & phosphoric) | Good |
| Typical Applications | Marine, offshore, chemical, food processing | General industrial, architectural |
| Max Operating Temp. | Up to +300 °C | Up to +300 °C |
| Feature | DIN 7967 PAL Nut (A4) | Nylon Insert Lock Nut (DIN 985) | Thin Jam Nut (DIN 439) |
|---|---|---|---|
| Locking Method | All-metal spring tension (slotted body) | Non-metallic nylon insert | Friction only (no locking) |
| Max Temperature | Up to +300 °C | Max ~120 °C (nylon limit) | Material-limited only |
| Profile | Thin / low profile | Standard height | Thin / low profile |
| Reusability | Good (metal spring retains tension) | Limited (nylon degrades) | Unlimited (no locking element) |
| Chemical Resistance | Excellent (A4 SUS316, all metal) | Limited by nylon compatibility | Good (all metal) |
| Vibration Resistance | High (active spring locking) | High (nylon grip) | Low (friction only) |
| Marine / Chloride Env. | Excellent (SUS316 Mo-alloyed) | Moderate | Good (if A4 grade) |
All dimensions in mm per DIN 7967. Tolerances per ISO 4759-1. Series 1 = metric coarse thread (standard). Series 2 & 3 = fine pitch threads (available on request).
| Thread d |
Pitch p (mm) |
Wrench Size s (mm) |
e min (mm) |
Nut Height m (mm) |
v (mm) | Unit Weight (g/pc) |
|---|---|---|---|---|---|---|
| M4 | 0.70 | 7 | 7.66 | 1.8 | 0.3 | ~0.17 |
| M5 | 0.80 | 8 | 8.79 | 2.0 | 0.4 | ~0.28 |
| M6 | 1.00 | 10 | 11.05 | 2.5 | 0.4 | ~0.40 |
| M8 | 1.25 | 13 | 14.38 | 3.0 | 0.5 | ~0.92 |
| M10 | 1.50 | 17 | 18.90 | 3.5 | 0.5 | ~1.43 |
| M12 | 1.75 | 19 | 21.10 | 4.0 | 0.6 | ~1.94 |
| M14 | 2.00 | 22 | 24.49 | 4.0 | 0.7 | ~2.55 |
| M16 | 2.00 | 24 | 26.75 | 5.0 | 0.7 | ~3.47 |
| M18 | 2.50 | 27 | 29.56 | 5.0 | 0.7 | ~4.18 |
| M20 | 2.50 | 30 | 32.95 | 5.0 | 0.8 | ~5.92 |
| M22 | 2.50 | 32 | 35.03 | 6.0 | 0.9 | ~8.57 |
| M24 | 3.00 | 36 | 39.55 | 6.0 | 0.9 | ~9.69 |
| M27 | 3.00 | 41 | 45.20 | 7.0 | 1.0 | ~13.26 |
| M30 | 3.50 | 46 | 50.85 | 7.0 | 1.1 | ~17.86 |
| M33 | 3.50 | 50 | 55.37 | 8.0 | 1.2 | ~22.44 |
| M36 | 4.00 | 55 | 60.79 | 9.0 | 1.3 | ~29.58 |
| M39 | 4.00 | 60 | 66.44 | 9.0 | 1.3 | ~32.64 |
| M42 | 4.50 | 65 | 71.30 | 11.0 | 1.4 | ~45.90 |
| M45 | 4.50 | 70 | 76.95 | 12.0 | 1.5 | ~55.08 |
| M48 | 5.00 | 75 | 82.60 | 14.0 | 1.6 | ~76.50 |
| M52 | 5.00 | 80 | 88.25 | 16.0 | 1.7 | ~96.90 |
* Unit weights (g/pc) are derived from DIN 7967 standard weight data and are approximate reference values based on SUS316 density (7.98 g/cm³). Actual weight may vary ±5% due to manufacturing tolerances. Contact FULLERKREG for certified weight data if required. v = slot offset dimension.
| Application Scenario | Recommended Size | Notes |
|---|---|---|
| Marine & offshore structures | M8 – M36 | SUS316 Mo-alloyed; superior seawater & salt spray resistance |
| Chemical processing equipment | M6 – M30 | Resists acids, chlorides, and process chemicals better than A2 |
| Food & beverage / pharmaceutical | M6 – M24 | A4 SUS316 meets hygiene and corrosion requirements |
| High-temperature assemblies (>120 °C) | M6 – M36 | All-metal; no nylon insert temperature limit |
| Vibration-prone machinery | M8 – M30 | Spring-action locking resists loosening without adhesives |
| Coastal & humid environments | M6 – M30 | A4 preferred over A2 where chloride exposure is expected |
| Reusable assemblies (maintenance-heavy) | M4 – M52 | Metal spring retains locking tension through multiple cycles |
| Fine-pitch thread applications | M8×1 – M39×3 (Series 2/3) | Contact FULLERKREG for fine-pitch series availability |
These nuts are manufactured to DIN 7967 — Self-locking counter nuts, prevailing torque type, all-metal. The standard defines three series: Series 1 (metric coarse thread, 9 locking teeth), Series 2 and Series 3 (metric fine pitch threads, 9 locking teeth). The locking action is achieved by a radial slot through the nut body combined with a deliberate thread offset between the two halves, creating a spring-like clamping force on the bolt thread flanks. Unlike nylon insert nuts (DIN 985, DIN 6926), DIN 7967 PAL nuts are fully metallic and are not subject to temperature or chemical limitations imposed by non-metallic inserts.
Related standards: ISO 7042 (all-metal prevailing torque hex nuts) · DIN 985 (nylon insert lock nut) · DIN 439 (thin hex nut / jam nut) · ISO 2320 (prevailing torque requirements) · ISO 4759-1 (dimensional tolerances)
DIN 7967 PAL Self-Locking Counter Nuts — A4 Marine Stainless Steel (SUS316), Bright Passivated
| [Photo 1] | [Photo 2] | [Photo 3] | [Photo 4] |
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📐 DIN 7967 Precision — Every batch produced and inspected to full dimensional and prevailing torque requirements.
🔩 Full Material Traceability — SUS316 mill certificates and RoHS compliance documentation available on request.
📦 Flexible MOQ & Bulk Packaging — From sample packs to pallet quantities; custom labeling and kitting available.
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