ISO 12474 Hex Socket Head Cap Screws (Fine Pitch)
ISO 12474 hexagon socket head cap screws with metric fine pitch thread, M8×1 to M36×3 — the fine-pitch member of the ISO 4762 socket family, with the collected per-size tables: fine pitches, plain/knurled head d k, d s, k, socket s, depth t and thread length b.
Last updated: 2026-11
Specifications
ISO 12474 takes the socket cap screw into fine pitch: the hex-socket head envelope of ISO 4762 (this size for size — sockets, head heights and seats carry over), but with a fine thread that earns its place where a coarse 4762 thread is the weak link — thin-walled housings, hydraulic and pneumatic ports, high-strength steel where the finer helix raises preload per turn of torque and resists vibrational walk-off. The collected tables run M8×1 to M36×3 with the two-fine-pitch structure printed per size (Fine thread 1 / Fine thread 2, "/" where a second fine pitch does not exist and for all sizes above M20 — order "M10×1.25" never "fine M10"). Per size they carry the split head diameter d k — "For plain heads" and "For knurled heads" max rows (the knurled values are the source's "*not standardized, reference values" candidates; see the table footnote and quote the head form) — plus shank d s, head height k, socket across-flats s, socket depth t (min) and thread length b. Property classes and finishes are not printed by the collected specification and stay per RFQ.
| Standard | ISO 12474 — hexagon socket head cap screws with metric fine pitch thread (fine-pitch counterpart of ISO 4762) |
|---|---|
| Series | M8×1 – M36×3 (three source column groups: M8/M10/M12, M14/M16/M20, M24/M30/M36; Fine thread 1/2 rows, "/" where no second fine pitch) |
| Tabulated geometry | Per size: pitch P (fine-1/fine-2), d k max split "For plain heads" / "For knurled heads", d k min, d s (max/min), k (max/min), socket s (max/min, 6.02–27.065), t (min, 4–19), thread length b (28–84) |
| Head form | Plain or knurled head — quote the form at RFQ; the source marks the knurled d k values "*not standardized, reference values" (see table footnote) |
| Property classes / finishes | Not tabulated by the collected specification — per RFQ (state class and pitch explicitly: 12.9 M10×1.25, not "fine M10") |
| Attribute | M8 | M10 | M12 |
|---|---|---|---|
| P — Thread Pitch — Fine thread 1 | 1 | 1 | 1.5 |
| Fine thread 2 | / | 1.25 | 1.25 |
| d k — max — For plain heads | 13 | 16 | 18 |
| For knurled heads | 13.27 | 16.27 | 18.27 |
| min | 12.73 | 15.73 | 17.73 |
| d s — max | 8 | 10 | 12 |
| min | 7.78 | 9.78 | 11.73 |
| k — max | 8 | 10 | 12 |
| min | 7.64 | 9.64 | 11.57 |
| s — max | 6.14 | 8.175 | 10.175 |
| min | 6.02 | 8.025 | 10.025 |
| t — min | 4 | 5 | 6 |
| Length of Thread b | 28 | 32 | 36 |
- Row 2 (Fine thread 2): The source prints '/' in the Fine thread 2 row where a second fine pitch does not exist (and for all sizes above M20) — kept verbatim.
- Row 4 (For knurled heads): The source splits d k max into plain-head and knurled-head values (knurled +0.27 to +0.46 as printed); the knurled values are the source footnote's "*not standardized, reference values" candidates — quote the head form at RFQ.
| Attribute | M14 | M16 | M20 |
|---|---|---|---|
| P — Thread Pitch — Fine thread 1 | / | 1.5 | 2 |
| Fine thread 2 | 1.5 | / | 1.5 |
| d k — max — For plain heads | 21 | 24 | 30 |
| For knurled heads | 21.33 | 24.33 | 30.33 |
| min | 20.67 | 23.67 | 29.67 |
| d s — max | 14 | 16 | 20 |
| min | 13.73 | 15.73 | 19.67 |
| k — max | 14 | 16 | 20 |
| min | 13.57 | 15.57 | 19.48 |
| s — max | 12.212 | 14.212 | 17.23 |
| min | 12.032 | 14.032 | 17.05 |
| t — min | 7 | 8 | 10 |
| Length of Thread b | 40 | 44 | 52 |
- Row 1 (P — Thread Pitch — Fine thread 1): The source prints '/' where a second fine pitch does not apply — at (M14) in the Fine thread 1 row; kept verbatim.
- Row 2 (Fine thread 2): The source prints '/' in the Fine thread 2 row where a second fine pitch does not exist (M16 and M20 here); kept verbatim.
- Row 4 (For knurled heads): The source splits d k max into plain-head and knurled-head values (knurled +0.33 as printed); the knurled values are the source footnote's "*not standardized, reference values" candidates — quote the head form at RFQ.
| Attribute | M24 | M30 | M36 |
|---|---|---|---|
| P — Thread Pitch — Fine thread 1 | 2 | 2 | 3 |
| Fine thread 2 | / | / | / |
| d k — max — For plain heads | 36 | 45 | 54 |
| For knurled heads | 36.39 | 45.39 | 54.46 |
| min | 35.61 | 44.61 | 53.54 |
| d s — max | 24 | 30 | 36 |
| min | 23.67 | 29.67 | 35.61 |
| k — max | 24 | 30 | 36 |
| min | 23.48 | 29.48 | 35.38 |
| s — max | 19.275 | 22.275 | 27.275 |
| min | 19.065 | 22.065 | 27.065 |
| t — min | 12 | 15.5 | 19 |
| Length of Thread b | 60 | 72 | 84 |
- Row 2 (Fine thread 2): The source prints '/' in the Fine thread 2 row for all sizes above M20 — no second fine pitch exists; kept verbatim.
- Row 4 (For knurled heads): The source splits d k max into plain-head and knurled-head values (knurled +0.39 to +0.46 as printed); the knurled values are the source footnote's "*not standardized, reference values" candidates — quote the head form at RFQ.
Materials
- Material and property class specified per RFQ — name diameter and pitch together at quotation
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 12474 Hex Socket Head Cap Screws (Fine Pitch)) 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 quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at 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
ISO 12474 or ISO 4762 — when does fine pitch pay off in a socket screw?
When the thread, not the head, is the constraint. The head envelope is shared: the collected 12474 tables carry the same socket sizes (s 6–27 across the range) and head heights as the 4762 series, so your hex keys and counterbores do not change. What changes is the helix, and it pays in three places: in tapped bosses of high-strength or thin-walled material, where a fine pitch puts more load-bearing flank depth into less wall; in dynamic joints, where the finer helix resists backing off and lets torque convert into clamp more efficiently; and in adjustment duty, where each turn moves the clamp less. The discipline is assembly-side: fine socket screws galle more on alloy steels, so lubricant and pitch-specific torque matter, and the two-pitch structure (the source prints Fine thread 1 and 2 rows, with a second fine pitch existing only through M20) means mixed-stock bins are the classic failure — order "M12×1.25", not "fine M12". Thread length b is a single value per size in the collected tables (28–84 mm); check your grip against it before ordering, and name the head form (plain or knurled) with the RFQ.
What is the MOQ and lead time for this screw type?
The minimum order quantity is 10,000 pieces. Stock items ship in 3–7 days; non-stock items are confirmed at quotation. Common sizes in this screw type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
Related knowledge
- Thread-Forming vs Thread-Cutting vs Thread-Rolling Self-Tapping Screws: What the Evidence Settles on Base Material
- Screw Family Selection by Base Material: Wood, Machine and Self-Tapping Threads, Engagement and Coating
- Hex Bolts vs Socket Head Cap Screws: What the Evidence Settles on Strength, Clearance and Cost
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