Hexagon-socket screws machined to order to the dimensional requirements of ISO 4762 (socket head cap screws, M3–M36, legacy DIN 912), DIN 7984 (low head, reduced loadability, M3–M24), ISO 10642 (countersunk, M2–M20, legacy DIN 7991), ISO 7380-1 (button head, M3–M16; ISO 7380-2 where a collar is required) and ISO 4026–4029 (socket set screws — flat, cone, dog and cup point, legacy DIN 913–916), in nickel aluminium bronze (CuAl10Ni5Fe4 — CW307G / CA104) and aluminium silicon bronze (CuAl6Si2Fe — CW301G / CA107) to the applicable drawing or material specification. M3 to M36 metric; imperial to drawing. Supplied with material certification and, where specified, to NES 833 / DEF STAN 02-833 for NAB, NES 834 / DEF STAN 02-834 Pt 2 (superseded by 02-879 Pt 2 Annex D, Sept 2011) for SAB, and the DEF STAN 02-862 Part 2 manufacturing route.
Socket screws in these alloys are machined from bar with machined threads and a machined or broached socket. The ISO and DIN socket-screw standards are written primarily for steel (the non-ferrous designations they once referenced under ISO 8839 have been withdrawn, and the 2026 editions of ISO 4026–4029 and ISO 10642 cover steel and stainless only); in bronze they are used as dimensional and form references, and material and mechanical requirements come from the drawing and naval material specification. Grub screws in SAB are a regular naval valve and instrumentation item. No minimum order quantity.
Maximum values (dk max, k max) from the standard; s is the hexagon socket size. ISO 4762 tabulates these preferred sizes; M18, M22, M27 and M33 are not in its table.
| Thread | Pitch (mm) | Head dia dk (mm) | Head height k (mm) | Socket s (mm) |
|---|---|---|---|---|
| M3 | 0.5 | 5.5 | 3 | 2.5 |
| M4 | 0.7 | 7 | 4 | 3 |
| M5 | 0.8 | 8.5 | 5 | 4 |
| M6 | 1.0 | 10 | 6 | 5 |
| M8 | 1.25 | 13 | 8 | 6 |
| M10 | 1.5 | 16 | 10 | 8 |
| M12 | 1.75 | 18 | 12 | 10 |
| M14 | 2.0 | 21 | 14 | 12 |
| M16 | 2.0 | 24 | 16 | 14 |
| M20 | 2.5 | 30 | 20 | 17 |
| M24 | 3.0 | 36 | 24 | 19 |
| M30 | 3.5 | 45 | 30 | 22 |
| M36 | 4.0 | 54 | 36 | 27 |
Head height equals d throughout. Head diameter equals 1.5d from M12 upward and is 1 mm larger than 1.5d at M3 to M10.
Non-standard head diameters, drilled heads for wire locking, captive or shoulder forms, left-hand and imperial to drawing — see Made to Drawing.
CuAl10Ni5Fe4. The higher-strength alloy, with excellent seawater, erosion and cavitation resistance; commonly specified for structural and immersed fastenings. Naval material standard NES 833 / DEF STAN 02-833 Part 2. Relative magnetic permeability typically around 1.4–1.5. Full data, designations and cross-references on the NAB material page.
CuAl6Si2Fe. Good machinability, ductile, and formulated for controlled low magnetic permeability — relative magnetic permeability not exceeding 1.05 (DEF STAN 02-879 Part 2 Annex D, D.2.8; batch-tested to D.4.5) — used for mine countermeasures vessels and other naval low-signature applications. Tighter permeability limits are a drawing or contract requirement and are handled at enquiry stage. Naval material standard NES 834 / DEF STAN 02-834 Part 2, subsequently incorporated into DEF STAN 02-879 Part 2 Annex D. Full data on the SAB material page.
Source-material certification supplied as standard, with traceability to the bar heat maintained through manufacture. Where the drawing calls for DEF STAN 02-862 Part 2, socket screws are machined from bar with machined threads and post-machining stress relief per clause 8.2.4 (NAB) or 8.2.5 (SAB), with heat treatment and stress relief records supplied where required by the drawing, specification or purchase order. Marking, EN 10204 3.1 certification, dimensional inspection reports and CoC as required by the order; EN 10204 3.2 where agreed in advance and supported by the material source and inspection arrangements.
The drawing and specification govern. Alloy designations above are cross-references, not statements of equivalence.
Drilled heads, shoulders, captive forms, odd points on grub screws, imperial — send the drawing and we'll quote within 24 hours.
Send us your drawing or spec reference and we'll come back with a price and lead time. No minimum order quantity.