RS PRO Bright Zinc Plated Steel Hex Socket Countersunk Screw, DIN 7991, M8 x 20mm

RS PRO popular hexagon socket countersunk screws are an excellent choice when you need a fastener to sit flush or below the surface of your material.
These metric thread countersunk screws are produced in 10.9 grade steel. The finish of these fasteners is bright zinc-plated which ensures an attractive, quality appearance and finish wherever they are used. They are ideal for light fastening applications in machine tooling, security guarding, panel building and for general fastening.
These screws can be tightened or undone using an Allen key or a hex key.

Various thread sizes available, including M3, M4, M5, M6, M8, M10, M12 and M16
Manufactured from Bright Zinc Plated Steel (BZP)
Used in applications where a wider head and lower profile is required
Also used in many internal joinery applications
Have the marking on the head
More resilient than 8.8 grade
Nominal strength of 1040 N/mm²
Yield strength of 940 N/mm²

Although uses may vary, as standard, these screws are fasteners for industrial equipment or machines which requires parts to be fixed onto a surface or together. The socket will need to be the same metric thread as the screw itself. As an example, some of the types of uses would be:
Woodworking
Domestic applications
Fasteners and fixings
Machine tooling and repair
Security guarding
Electronic applications
Automotive industry
Medical applications
Facilities and maintenance applications

Socket screws are defined by their name. They are a type of threaded bolt which screws into the intended socket. There are various thread sizes and lengths and can be used for both industrial and personal purposes. Good quality and reliable RS PRO socket screws ensures the fixing will remain strong and stable, whatever the application.

Meaning bright zinc plating, a shiny coating is applied to the steel, this process prevents corrosion and rusting. If the application is situated within a harsh environment, BZP will provide much-needed longevity and reliability. Although it may not be as effective as stainless steel, the added benefit would be the price. As stainless steel is completely rustproof, but expensive, BZP Steel offers a great solution and is massively cost-effective.

Requires a Hex key
We offer a range of hexagon countersunk socket screws in bright zinc plated steel, available in various thread sizes and lengths. Refer to the Datasheet and Range Overview download file for details.
If bright zinc plated steel is not what you are looking for we also offer steel hexagon countersunk socket screws with a self-colour (black oxide) finish or alternatively A2 (306) and A4 (316) stainless steel.

Threaded in accordance with DIN 7991

When you need to fasten materials without protruding screws on your surface, choose these RS PRO hexagon socket countersunk screws. They sit flush with or just below the surface of the material you're working with for a smoother finish. They also offer exceptional tensile strength and wear resistance as they're made from 10.9-grade steel.


The screws are bright zinc-plated (BZP), which prevents rust and corrosion. This makes these screws a dependable and long-lasting choice. You can use a hex or Allen key to easily screw them in or out.


The screws keep you and your workspace safe from dangerous static electricity build-up as they meet international ANSI/ESD S20.20:2014 and BS EN 61340-5-1:2007 electrostatic control standards. They're also threaded according to DIN 7991 specifications for hexagon socket countersunk head cap screws. You can use them for medical, electronic and domestic applications. They're also a good choice for the automotive and machine industries.