DIN 7978 Taper Pins with Internal Thread (Type A)
Taper pins with internal thread per DIN 7978, type A — nominal diameters 6 to 50 mm at h10 in the collected table, each with its internal puller thread (M4 at Φ6 up to M24 at Φ50), thread hole d1, thread depths t1/t2, the t tip dimension and the a end dimension.
Last updated: 2026-11
Specifications
DIN 7978 combines the two ideas of this batch on one pin: a taper pin's wedge fit (drive in, seat over the full cone, drive out from the small end) with the internal puller thread of the DIN 7979D pull dowel. The internal thread gives the extraction screw a grip even though the pin sits in a tapered bore — useful precisely because a taper pin wedges tighter in service, and a plain taper pin in a heavily loaded joint may need real force to start it moving from the small end. The collected table (type A) runs Φ6 to Φ50 at h10 (max = nominal) and pairs each diameter with its thread: M4 at Φ6 through M6 at Φ10, M8 at Φ12–14, M10 at Φ16, M12 at Φ20, up to M24 at Φ50, with the tapped depth t1, the minimum thread depth t2, the thread-hole diameter d1 and the tip dimension t printed per size, plus the a end dimension the ISO 2339 taper series carries. For the parallel-bore equivalent, see the DIN 7979D pull dowel page.
| Standard | DIN 7978 — taper pins with internal thread, type A, h10 (max = nominal size) |
|---|---|
| Size range | Nominal diameters Φ6, 8, 10, 12, 14, 16, 20, 25, 30, 40, 50 mm |
| Pin diameter d (max/min by size) | max = nominal 6 to 50 mm; min 5.952 mm at Φ6 to 49.9 mm at Φ50 — see per-size table |
| Puller thread d2 (by size) | M4 (Φ6), M5 (Φ8), M6 (Φ10), M8 (Φ12, Φ14), M10 (Φ16), M12 (Φ20), M16 (Φ25), M20 (Φ30, Φ40), M24 (Φ50) |
| Thread hole d1 (by size) | 4.3 mm at Φ6 to 25 mm at Φ50 — see per-size table |
| Thread depths t1 / t2 min (by size) | t1 6 mm at Φ6 to 36 mm at Φ50; t2 min 10 mm at Φ6 to 50 mm at Φ50 — see per-size table |
| Tip dimension t (by size) | 1 mm at Φ6 to 2.5 mm at Φ50 — see per-size table |
| End dimension a (≈ by size) | 0.8 mm at Φ6 to 6.3 mm at Φ50 — see per-size table |
| Extraction | Thread an extraction screw into the internal thread and pull the pin from the small end; the taper seats tighter in service, so allow screw access when laying out the joint |
| Nominal diameter d | d min (mm) | a approx. (mm) | Thread d2 | d1 (mm) | t1 (mm) | t2 min (mm) | t (mm) |
|---|---|---|---|---|---|---|---|
| 6 | 5.952 | 0.8 | M4 | 4.3 | 6 | 10 | 1 |
| 8 | 7.942 | 1 | M5 | 5.3 | 8 | 12 | 1.2 |
| 10 | 9.942 | 1.2 | M6 | 6.4 | 10 | 16 | 1.2 |
| 12 | 11.93 | 1.6 | M8 | 8.4 | 12 | 20 | 1.2 |
| 14 | 13.93 | 1.6 | M8 | 8.4 | 12 | 20 | 1.2 |
| 16 | 15.93 | 2 | M10 | 10.5 | 16 | 25 | 1.5 |
| 20 | 19.916 | 2.5 | M12 | 13 | 18 | 27 | 1.5 |
| 25 | 24.916 | 3 | M16 | 17 | 24 | 34 | 2 |
| 30 | 29.916 | 4 | M20 | 21 | 30 | 42 | 2 |
| 40 | 39.9 | 5 | M20 | 21 | 30 | 42 | 2 |
| 50 | 49.9 | 6.3 | M24 | 25 | 36 | 50 | 2.5 |
Materials
- Material and finish specified per RFQ — the collected specification table covers geometry 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 7978 Taper Pins with Internal Thread (Type A)) 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
Taper pin with internal thread (DIN 7978) or parallel pull dowel (DIN 7979D)?
The thread feature is the same idea; the pin body is not. The DIN 7978 taper keeps the taper pin's serviceability — knock-apart joints that re-seat on re-assembly, tolerance take-up as the bore wears — while adding controlled extraction. The DIN 7979D parallel keeps the dowel's positionally repeatable, precision-located joint (m6 into a reamed bore) with the same pull-out feature. So the choice tracks the body, not the thread: pick the taper where the joint is serviced often and positional repeatability after re-assembly is secondary; pick the parallel where the joint needs dowel-grade location every time it is rebuilt. Size ladders differ too — the taper series starts at Φ6 here (the plain taper pins DIN 1 / ISO 2339 page covers the smaller sizes), while the parallel pull dowel runs to Φ80.
What should an RFQ for this pin type state?
State the pin type, the standard designation, the nominal size and length, material if the drawing names one, and quantity per size — plus destination country. Commercial terms are confirmed 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