DIN 912 A4 Stainless Socket Head Cap Screw Sizes Guide
DIN 912 A4 stainless socket head cap screws are high-strength metric fasteners designed for use in demanding environments where corrosion resistance is essential. These screws feature a cylindrical head and internal hex drive, making them ideal for machinery, marine equipment, engineering assemblies and outdoor installations.
Manufactured from A4 stainless steel (also known as marine grade stainless steel), these fasteners provide excellent resistance to corrosion, saltwater and harsh environments. Because of this, A4 socket head cap screws are commonly used in marine applications, coastal environments, food processing equipment and chemical industries.
What sizes do DIN 912 A4 stainless cap screws come in?
We stock DIN 912 A4 stainless socket head cap screws from M2 up to M24, in lengths from 6mm to 200mm depending on the diameter. A4 (grade 316) is marine-grade stainless steel, so these are the screws to choose for boats, coastal sites, food processing and chemical environments. Each size takes a set Allen key – for example M6 takes 5mm and M8 takes 6mm.
- Most popular sizesM4, M5, M6, M8, M10, M12
- Smallest / largestM2 / M24
- MaterialA4 (316) marine-grade stainless steel
- Equivalent standardISO 4762
What Are DIN 912 A4 Socket Head Cap Screws?
DIN 912 is the German standard that defines the dimensions of socket head cap screws; its international equivalent is ISO 4762. These screws are recognised by their:
• Cylindrical head
• Internal hex (Allen) drive
• High tensile strength
• Precision metric threading
The internal hex drive allows high torque to be applied using an Allen key, making DIN 912 screws ideal for applications where space is limited, or where the head needs to sit flush in a counterbored hole.
Common DIN 912 A4 Stainless Screw Sizes
A4 stainless socket head cap screws are available in a wide range of metric diameters to suit different engineering applications. Each diameter comes in multiple lengths depending on the application and required thread engagement. Click a size to see it in our shop.
| Size | Lengths available |
|---|---|
| M2 | 8mm |
| M3 | 6, 8, 10, 12, 16, 20, 25, 30mm |
| M4 | 6, 8, 10, 12, 16, 18, 20, 22, 25, 30, 35, 40, 45mm |
| M5 | 10, 12, 16, 25, 30, 40, 45, 50, 55, 60, 65, 80mm |
| M6 | 8, 10, 16, 18, 20, 25, 35, 40, 45, 55, 60, 65, 70, 75, 100mm |
| M8 | 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 120mm |
| M10 | 16, 25, 30, 35, 45, 50, 60, 65, 70, 75, 80, 85, 110, 120, 130mm |
| M12 | 20, 25, 30, 35, 40, 45, 50, 65, 70, 80, 90, 100, 110, 120, 130, 160, 200mm |
| M14 | 25mm |
| M16 | 30, 40, 55, 60, 70, 110, 130, 160mm |
| M20 | 35, 70, 110, 120mm |
| M24 | 50, 55mm |
Why Choose A4 Stainless Socket Cap Screws?
A4 stainless steel offers several advantages compared to standard fastener materials.
Superior corrosion resistance
A4 stainless steel performs well in marine, coastal and outdoor environments.
Excellent durability
These fasteners are suitable for long-term installations exposed to moisture or chemicals.
Precision engineering applications
Socket head cap screws are widely used in machinery, equipment assembly and mechanical systems.
Choosing the Correct Screw Size
When selecting a DIN 912 A4 socket head cap screw, consider the following:
• Required diameter (M6, M8, M10 etc.)
• Required length
• Environmental conditions
Using the correct size and material ensures safe and reliable fastening performance.
DIN 912 A4 Stainless Screws at Sticky Stuff Store
Sticky Stuff Store supplies a wide range of DIN 912 A4 stainless socket head cap screws in multiple metric sizes and lengths. These corrosion-resistant fasteners are ideal for marine, outdoor and engineering applications where durability and reliability are essential.
Browse our range of A4 stainless socket head cap screws to find the correct size for your project.
Allen key sizes for DIN 912 cap screws
Match your screw to the right hex key.
| Thread size | Allen key (hex) size |
|---|---|
| M2 | 1.5mm |
| M2.5 | 2mm |
| M3 | 2.5mm |
| M4 | 3mm |
| M5 | 4mm |
| M6 | 5mm |
| M8 | 6mm |
| M10 | 8mm |
| M12 | 10mm |
| M14 | 12mm |
| M16 | 14mm |
| M20 | 17mm |
| M24 | 19mm |
Frequently asked questions
Is A4 stainless steel the same as marine grade?
Yes. A4 stainless is grade 316, often called marine-grade stainless steel, because the added molybdenum resists salt water far better than A2 (304).
What size Allen key do I need for a socket head cap screw?
It depends on the thread size. For DIN 912 / ISO 4762 cap screws: M3 takes 2.5mm, M4 3mm, M5 4mm, M6 5mm, M8 6mm, M10 8mm, M12 10mm, M16 14mm and M20 17mm.
What's the difference between A2 and A4 stainless steel?
A2 (grade 304) stainless resists rust well and suits most indoor and outdoor jobs. A4 (grade 316) contains molybdenum, which gives it much better resistance to salt water and chemicals – so choose A4 for marine, coastal, pool and food-processing use.
Is DIN 912 the same as ISO 4762?
Yes – ISO 4762 is the international standard that replaced DIN 912, and the two are interchangeable for everyday use. Many suppliers, including us, still use the DIN 912 name.
How do I choose the right length of cap screw?
Measure from under the head to the tip. As a rule of thumb, aim for thread engagement of at least 1 to 1.5 times the screw diameter in steel – for example at least 8–12mm of thread in the hole for an M8 screw.
Related fastener guides
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