ISO 8747 Countersunk Head Grooved Pins
ISO 8747 countersunk-head grooved pins, d1 1,4 to 20 — the flush-mounted grooved pin, tabulated with dk and c head rows over a 13-length groove ladder (l 3 to 40); no k/r rows on the collected page.
Last updated: 2026-11
Specifications
The countersunk-head grooved pin disappears into the surface: the head seats into a countersunk bore flush with the workpiece face, while the grooved shank below locks in the bore exactly like its unheaded siblings. That flush seat is the point — sliding mating parts, sealed housings, and any joint where a proud head would snag, mark or add stack height. The collected table covers d1 1,4 → 20 with head diameter dk (2,7 → 31,5 max., 2,3 → 30,7 min.) and the c row (0,42 → 6), plus d1 max/min per column; the groove-diameter ladder runs 13 lengths from l 3 → 40 at the usual +0,05/0 / ±0,05 / ±0,1 bands. The collected page tabulates no k (head height) or r row — flush geometry has no standing height — so head-height-dependent checks are per RFQ. The protruding-head counterpart is ISO 8746, also in this catalog. Material, hardness and finish are not tabulated — per RFQ.
| Standard | ISO 8747 — countersunk head grooved pins (flush seat) |
|---|---|
| Size range | d1 1,4 – 20 in the collected rows (d1 max/min per column; min. 1,35 → 19,8) |
| Head geometry | dk max. 2,7 → 31,5 / min. 2,3 → 30,7; c 0,42 → 6 |
| Not tabulated | k (head height) and r rows — flush countersunk geometry; double-shear values; material, hardness, finish — per RFQ |
| Length ladder | l 3 – 40 (13 lengths) with groove diameter per length |
| Designation note | ISO 8746 is the round-head counterpart in this catalog — countersunk for flush, round head for retention |
| Row label | 1,4 | 1,6 | 2 | 2,5 | 3 | 4 | 5 | 6 | 8 | 10 | 12 | 16 | 20 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| d1 nominal | 1,4 | 1,6 | 2 | 2,5 | 3 | 4 | 5 | 6 | 8 | 10 | 12 | 16 | 20 |
| max. | 1,4 | 1,6 | 2 | 2,5 | 3 | 4 | 5 | 6 | 8 | 10 | 12 | 16 | 20 |
| min. | 1,35 | 1,55 | 1,95 | 2,425 | 2,925 | 3,9 | 4,9 | 5,9 | 7,85 | 9,85 | 11,8 | 15,8 | 19,8 |
| dk max. | 2,7 | 3 | 3,7 | 4,6 | 5,25 | 7,25 | 9,1 | 10,8 | 14,4 | 16 | 19 | 26 | 31,5 |
| min. | 2,3 | 2,6 | 3,3 | 4,2 | 4,95 | 6,75 | 8,5 | 10,2 | 13,6 | 14,9 | 17,7 | 23,7 | 30,7 |
| c | 0,42 | 0,48 | 0,6 | 0,75 | 0,9 | 1,2 | 1,5 | 1,8 | 2,4 | 3 | 3,6 | 4,8 | 6 |
| l Nominal | l min. | l max. | d1 1,4 | d1 1,6 | d1 2 | d1 2,5 | d1 3 | d1 4 | d1 5 | d1 6 | d1 8 | d1 10 | d1 12 | d1 16 | d1 20 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 2,8 | 3,2 | 1,5 | 1,7 | |||||||||||
| 4 | 3,7 | 4,3 | 1,5 | 1,7 | 2,15 | 2,7 | |||||||||
| 5 | 4,7 | 5,3 | 1,5 | 1,7 | 2,15 | 2,7 | 3,2 | ||||||||
| 6 | 5,7 | 6,3 | 1,5 | 1,7 | 2,15 | 2,7 | 3,2 | 4,25 | |||||||
| 8 | 7,7 | 8,3 | 1,7 | 2,15 | 2,7 | 3,2 | 4,25 | 5,25 | 6,3 | ||||||
| 10 | 9,7 | 10,3 | 2,15 | 2,7 | 3,2 | 4,25 | 5,25 | 6,3 | 8,3 | ||||||
| 12 | 11,6 | 12,4 | 2,7 | 3,2 | 4,25 | 5,25 | 6,3 | 8,3 | 10,35 | ||||||
| 16 | 15,6 | 16,4 | 3,2 | 4,25 | 5,25 | 6,3 | 8,3 | 10,35 | 12,35 | ||||||
| 20 | 19,5 | 20,5 | 4,25 | 5,25 | 6,3 | 8,3 | 10,35 | 12,35 | 16,4 | ||||||
| 25 | 24,5 | 25,5 | 5,25 | 6,3 | 8,3 | 10,35 | 12,35 | 16,4 | 20,5 | ||||||
| 30 | 29,5 | 30,5 | 6,3 | 8,3 | 10,35 | 12,35 | 16,4 | 20,5 | |||||||
| 35 | 34,5 | 35,5 | 8,3 | 10,35 | 12,35 | 16,4 | 20,5 | ||||||||
| 40 | 39,5 | 40,5 | 8,3 | 10,35 | 12,35 | 16,4 | 20,5 |
Materials
- Material and finish specified per RFQ — countersunk grooved pins commonly run spring or hardened steel; state the countersink angle and whether the head must sit at or slightly below flush at quotation, since the dk envelope fixes the cone
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 (ISO 8747 Countersunk Head Grooved Pins) 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
The collected page has no head-height (k) row — how do I size the countersink?
The flush head has no standing height to tabulate — its height is defined by the countersink cone, which is why the collected page carries only head diameter dk and the c row. To machine the bore you work from the dk envelope per your diameter: at d1 8, for example, dk runs 13,6 max. / 10,2 min., and the c row gives the edge distance (2,4 at d1 8). The countersink angle itself is not tabulated on this page — it follows the head cone the standard defines, and if your drawing specifies an angle or a flushness tolerance (at vs below flush), confirm the cone geometry per RFQ before machining, since a cone cut to the wrong angle seats the head off-flush in exactly the direction your joint cares about. What the page does tabulate completely: the groove-diameter ladder, l 3 – 40, with the tolerance bands — the drive fit is still sized by groove diameter, not by the head. Head-style comparison (flush vs the ISO 8746 round head) is on both pages.
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