TX Countersunk Reduced Thread Captive Screws

Torx (TX) Countersunk Reduced Thread Captive Screws are typically used for safety-critical applications and are required in various types of machinery under EU law.

These screws host an unthreaded portion below the head, otherwise known as the reduced thread. Once installed, often alongside Threaded Captive Washers, they are held “captive” within the target housing and cannot be fully removed.

The hexalobular Torx or 6 Lobe TX drive offers a reduced risk of cam-out compared to conventional drive types. If additional security is required, 6 Lobe Pin Torx Countersunk Captive Screws feature a Pin TX drive for increased tamper resistance.

TX Countersunk Reduced Thread Captive Screws require a countersink hole for installation, allowing the fastener to sit flush with the installation surface for an aesthetically pleasing finish.

Manufactured from A2 / 304 Stainless Steel as standard. Other specialised materials are available to order including Aluminium and Titanium.

Available at Fastenright in thread sizes M1.6 to M8 as standard, and lengths up to 60mm. Thread locking patches can also be supplied to reduce the effects of vibration.

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.

Our extensive range of Captive Screws can be found here.

d1 and L1 dimensions can be to customer specification.

Technical Data & Availability
Thread Diameter	M1.6	M2	M2.5	M3	M4	M5	M6	M8
dk (mm)	3.2	3.8	4.7	5.6	7.5	9.2	11	14.5
d1 (mm)	1.12	1.4	1.8	2.2	3	3.8	4.5	6.2
K (mm)	0.96	1.2	1.5	1.65	2.2	2.5	3	4
L1 (mm)	3.2	4	5	6	8	10	12	16
Available Lengths (L)	M1.6	M2	M2.5	M3	M4	M5	M6	M8