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Socket Countersunk Reduced Thread Captive Screws are designed to lock into place after they have been installed. They feature a countersunk head, allowing them to sit flush for an aesthetically pleasing finish.
These screws typically require a pre-drilled countersink hole for installation and are designed for use with Threaded Captive Washers. Once installed, they are retained within their target housing and cannot be fully removed.
Socket Countersunk Captive Screws are required by EU law on some pieces of machinery and equipment, while sees large usage within industrial machinery and military applications.
Manufactured from A2 / 304 Stainless Steel and A4 / 316 Stainless Steel as standard, with other specialist materials available to order including Aluminium, Titanium, Brass and Phosphor Bronze.
Available at Fastenright in thread sizes from M2 to M12 as standard, with lengths from 8mm to 200mm. See our full range of Captive Screws here.
Non-standard sizes, materials and finishes are available to order as specials, including small volume manufacture, modifications and bespoke parts made to drawings. Minimum order quantities apply.
d1 and L1 dimensions can be to customer specification.
| Technical Data & Availability | ||||||||||||
| Thread Diameter | M2 | M2.5 | M3 | M3.5 | M4 | M5 | M6 | M8 | M10 | M12 | ||
| dk (mm) | 4 | 5 | 6 | 6.5 | 8 | 10 | 12 | 16 | 20 | 24 | ||
| d1 (mm) | 1.4 | 1.8 | 2.2 | 2.6 | 3 | 3.8 | 4.5 | 6.2 | 8 | 9.5 | ||
| S(mm) | 1.27 | 1.5 | 2 | 2 | 2.5 | 3 | 4 | 5 | 6 | 8 | ||
| L1 (mm) | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 16 | 20 | 24 | ||
| K (mm) | 1.24 | 1.55 | 1.7 | 2.1 | 2.3 | 2.8 | 3.3 | 4.4 | 5.5 | 6.5 | ||
| Available Lengths (L) | M2 | M2.5 | M3 | M3.5 | M4 | M5 | M6 | M8 | M10 | M12 | ||
| 8mm |  |
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| 12mm | |
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| 18mm | |
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| 20mm | |
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| 22mm | |
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| 25mm | |
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| 30mm | |
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| 40mm | |
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| 45mm | |
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| 50mm | |
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| 55mm | |
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| 60mm | |
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| 65mm | |
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| 70mm | |
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| 75mm | |
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| 80mm | |
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| 90mm | |
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| 100mm | |
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| 110mm | |
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| 120mm | |
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| 130mm | |
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| 140mm | |
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| 150mm | |
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| 160mm | |
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| 170mm | |
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| 180mm | |
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| 190mm | |
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| 200mm | |
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| = Available Size not listed? Please contact us – we may be able to provide it. |
