DIN 7346 Spring Pins (Heavy Series)
DIN 7346 spring-type straight pins, heavy series, Φ2 to Φ50 — the thick-walled spring pin for shear-loaded drilled joints — with the full collected 27-size table: chamfer, as-coiled diameter limits, collapsed diameter, wall thickness and the source's single and double shear minimums.
Last updated: 2026-11
Specifications
DIN 7346 is the heavy-series spring pin: the same coiled, self-gripping principle as the light-duty form but with a much thicker section, so it approaches slotted-pin shear capacity while keeping the spring pin's forgiving fit in a plain drilled hole. It is the pin for shear-critical pivots and couplings in steel fabrication, agricultural and construction equipment — anywhere the pin is the joint's structural element rather than a retainer. The collected table runs Φ2 to Φ50 — 27 sizes — with the chamfer a, as-coiled pin diameter d (min / max), the source's approximate collapsed diameter d 2 ≈, wall thickness s, and its minimum single and double shear values in kilonewtons, rising to 500 / 1000 kN at Φ50. Lengths, materials and finishes are not printed by the collected specification and stay per RFQ.
| Standard | DIN 7346 — spring-type straight pins, heavy series (thick-section coiled pin for shear-loaded joints) |
|---|---|
| Size range | Nominal diameters Φ2 – Φ50 (27 sizes tabulated); length to order |
| Tabulated geometry | Per size: chamfer a, pin diameter d (min / max), collapsed diameter d 2 ≈, wall thickness s |
| Strength (source rows) | Minimum single and double shear in kN per size as printed by the source — e.g. 0.75 / 1.5 kN at Φ2, 500 / 1000 kN at Φ50 |
| Function | Springs against the drilled bore for uniform radial grip with near-slotted-pin shear capacity |
| Materials / strength | Not tabulated by the collected specification beyond the source shear rows — per RFQ (spring steel grade per duty) |
| Size | a | d — min | d — max | d 2 — ≈ | s | Minimum shear strength, single (kN) | Minimum double shear (kN) |
|---|---|---|---|---|---|---|---|
| Φ2 | 0.2 | 2.3 | 2.4 | 1.9 | 0.2 | 0.75 | 1.5 |
| Φ2.5 | 0.25 | 2.8 | 2.9 | 2.3 | 0.25 | 1.2 | 2.4 |
| Φ3 | 0.25 | 3.3 | 3.5 | 2.7 | 0.3 | 1.75 | 3.5 |
| Φ3.5 | 0.3 | 3.8 | 4 | 3.1 | 0.35 | 2.3 | 4.6 |
| Φ4 | 0.5 | 4.4 | 4.6 | 3.4 | 0.5 | 4 | 8 |
| Φ4.5 | 0.5 | 4.8 | 5 | 3.8 | 0.5 | 4.4 | 8.8 |
| Φ5 | 0.5 | 5.4 | 5.6 | 4.4 | 0.5 | 5.2 | 10.4 |
| Φ6 | 0.7 | 6.4 | 6.7 | 4.9 | 0.75 | 9 | 18 |
| Φ7 | 0.7 | 7.5 | 7.8 | 6 | 0.75 | 10.5 | 21 |
| Φ8 | 1.5 | 8.5 | 8.8 | 7 | 0.75 | 12 | 24 |
| Φ10 | 2 | 10.5 | 10.8 | 8.5 | 1 | 20 | 40 |
| Φ11 | 2 | 11.5 | 11.8 | 9.5 | 1 | 22 | 44 |
| Φ12 | 2 | 12.5 | 12.8 | 10.5 | 1 | 24 | 48 |
| Φ13 | 2 | 13.5 | 13.8 | 11 | 1.25 | 33 | 66 |
| Φ14 | 2 | 14.5 | 14.8 | 11.5 | 1.5 | 42 | 84 |
| Φ16 | 2 | 16.5 | 16.8 | 13.5 | 1.5 | 49 | 98 |
| Φ18 | 2 | 18.5 | 18.9 | 15 | 1.75 | 63 | 126 |
| Φ20 | 2 | 20.5 | 20.9 | 16.5 | 2 | 79 | 158 |
| Φ21 | 2 | 21.5 | 21.9 | 17.5 | 2 | 84 | 168 |
| Φ23 | 3 | 23.5 | 23.9 | 19.5 | 2 | 92 | 184 |
| Φ25 | 3 | 25.5 | 25.9 | 21.5 | 2 | 101 | 202 |
| Φ28 | 3 | 28.5 | 28.9 | 23.5 | 2.5 | 140 | 280 |
| Φ30 | 3 | 30.5 | 30.9 | 25.5 | 2.5 | 151 | 302 |
| Φ35 | 3 | 35.5 | 35.9 | 28.5 | 3.5 | 245 | 490 |
| Φ40 | 4 | 40.5 | 40.9 | 32.5 | 4 | 317 | 634 |
| Φ45 | 4 | 45.5 | 45.9 | 37.5 | 4 | 360 | 720 |
| Φ50 | 4 | 50.5 | 50.9 | 40.5 | 5 | 500 | 1000 |
Materials
- Material and finish specified per RFQ — the collected specification table covers geometry and the source's strength rows only
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (DIN 7346 Spring Pins (Heavy Series)) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantities and lead times for this family are confirmed at quotation — send your sizes, grades and quantities on the RFQ and the quote will carry a firm schedule. Sample availability is confirmed with the quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Heavy-series spring pin or slotted spring pin — what actually differs?
Wall shape. A slotted pin (DIN 1481 / ISO 8752) is a single-turn tube with one gap; the heavy coiled pin is rolled from a thick strip into multiple turns, so its wall is distributed and it compresses more evenly. In practice that means the coiled heavy pin drives into closer-to-nominal holes, survives more re-driving, and treats brittle hosts more gently, while matching the slotted pin's shear figures in the overlapping sizes — compare the tabulated minimum double-shear rows size for size. The choice usually settles on the hole process: where holes are punched or drift, the coiled pin's tolerance forgiveness pays; where maximum stiffness in the joint matters, run the comparison against the slotted table on this site.
What is the MOQ and lead time for this pin type?
Commercial terms for this family are confirmed at quotation — state sizes, tolerance class and quantities on the RFQ for a firm schedule. Common diameters in this pin type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support