ISO 21269 Hexagon Socket Head Cap Screws, Fine Pitch
ISO 21269 hexagon socket head cap screws with metric fine pitch thread M8x1 to M64x4 — the socket head for fine-pitch threading, with the collected b/dk/ds/e/k/r/s/t attribute ladder.
Last updated: 2026-11
Specifications
ISO 21269 is the fine-pitch member of the socket-cap-screw family this catalog already carries in coarse pitch: same cylindrical head, same hex socket, but a fine thread that clamps harder per turn, resists vibration back-off and reaches reliable preload on short engagement — the standard pick for machine-tool spindles, hydraulic manifolds and any adjusted joint where a coarse pitch would creep. The collected ladder runs M8x1 to M64x4 with the fine-pitch alternates from the source's second header row merged into the size labels (M10x1/(M10x1,25), M12x1,5/(M12x125) — that missing comma is the source's own print, flagged verbatim). Around it: thread engagement b (28 → 140), head diameter dk max (13 → 96), shank ds max, across-corners e min (6,863 → 52,531), head height k (= d across the ladder), fillet r, socket width s (6 → 46) and socket depth t min (4 → 38). The source's M46x3 size label between M42 and M56 is carried verbatim (the coarse series would read M48) and flagged. Property class (these are commonly 8.8/10.9/12.9 class steels) and finish are not tabulated — per RFQ.
| Standard | ISO 21269 — hexagon socket head cap screws with metric fine pitch thread |
|---|---|
| Size range | M8x1 – M64x4; fine-pitch alternates from the source's second header row merged into the size labels |
| Head geometry | dk max 13 → 96 mm; k = d across the ladder; socket width s 6 → 46; socket depth t min 4 → 38 |
| Thread engagement | b: 28 → 140 mm across the ladder |
| Print quirks | (M12x125) missing comma and the M46x3 size label carried verbatim, flagged — confirm large sizes per RFQ |
| Material / class / finish | Not tabulated by the collected specification — per RFQ |
| d x P | M8x1 | M10x1 / (M10x1,25) | M12x1,5 / (M12x125) | (M14x1,5) | M16x1,5 | M20x1,5 / (M20x2) | M24x2 | M30x2 | M36x3 | M42x3 | M46x3 | M56x4 | M64x4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| b | 28 | 32 | 36 | 40 | 44 | 52 | 60 | 72 | 84 | 96 | 108 | 124 | 140 |
| dk max | 13 | 16 | 18 | 21 | 24 | 30 | 36 | 45 | 54 | 63 | 72 | 84 | 96 |
| ds max | 8 | 10 | 12 | 14 | 16 | 20 | 24 | 30 | 36 | 42 | 48 | 56 | 64 |
| e min | 6,863 | 9,149 | 11,429 | 13,716 | 15,996 | 19,437 | 21,734 | 25,154 | 30,854 | 36,571 | 41,131 | 46,831 | 52,531 |
| k | 8 | 10 | 12 | 14 | 16 | 20 | 24 | 30 | 36 | 42 | 48 | 56 | 64 |
| r | 0,4 | 0,4 | 0,6 | 0,6 | 0,6 | 0,8 | 0,8 | 1 | 1 | 1,2 | 1,6 | 2 | 2 |
| s | 6 | 8 | 10 | 12 | 14 | 17 | 19 | 22 | 27 | 32 | 36 | 41 | 46 |
| t min | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 15,5 | 19 | 24 | 28 | 34 | 38 |
- Row 1 (b): the source's alternate-size header row prints (M12x125) without the decimal comma (carried verbatim into the 'M12x1,5 / (M12x125)' column label)
- Row 8 (t min): the source's size ladder prints M46x3 between M42 and M56 where the coarse series would read M48 - carried verbatim, confirm large sizes per RFQ
Materials
- Property class and finish specified per RFQ — socket cap screws commonly run class 8.8/10.9/12.9 alloy steel; state the clamp load, service temperature and any stainless need at quotation, and match the fine pitch to your tapped hole exactly (the ladder stacks alternates per nominal)
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 21269 Hexagon 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
When is a fine-pitch socket cap screw (ISO 21269) the right call over the coarse-pitch version?
Three cases. Short engagement: fine pitch puts more load-bearing threads into a thin boss, so a M10x1 screw engages reliably where a M10 coarse might strip. Vibration: the shallow helix angle resists back-off, which is why machine-tool and hydraulic builders specify fine pitch on adjusted joints. Precision preload: each turn moves the clamp less, so torque wrenches resolve smaller preload steps. What you give up: coarse pitch tolerates dirt and handling damage better and drives faster. The collected ladder covers M8x1 through M64x4 with per-nominal alternates (e.g. M10x1/(M10x1,25), M20x1,5/(M20x2)) — match your tapped hole exactly. Two verbatim print quirks are flagged rather than corrected: the source prints (M12x125) without its comma, and the size between M42 and M56 reads M46x3 — confirm any order in that range per RFQ. Property class and finish per RFQ as always for socket cap screws.
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