Stainless steel - Hexagon socket countersunk head screw

Why Choose Stainless Countersunk Screws?

In high-end manufacturing, the fastener should enhance the product, not detract from it. Stainless steel countersunk screws are the preferred choice when the screw head must disappear. By sitting flush, they allow for easy cleaning, prevent clothing snags, and offer an aerodynamic profile. The use of stainless steel ensures that this "invisible" fastener does not become a visible eyesore due to rust streaks or staining over time.

Grade Selection Guide: A2 vs A4

Choosing the correct stainless grade is critical for the longevity of your assembly. Here is a quick comparison:

Feature	Grade 304 (A2)	Grade 316 (A4)
Environment	Indoor, Dry Outdoor, Urban	Marine, Coastal, Chemical
Key Resistance	Rain, Humidity, Oxidation	Salt Water, Chlorides, Acids
Best For	Furniture, Interior Fit-out	Boat Decking, Lab Equipment

Quality Assurance

Fastener Core ensures that our materials perform as promised. An EN 10204 3.1 Material Certificate verifying the chemical composition of the stainless steel is available upon request. Please note that third-party inspection services require an additional fee.

Common Applications

These flush-fitting screws are widely used in sectors prioritizing finish and function:

• Marine Decking: Fastening planks and fittings where a protruding head would be a trip hazard.
• Food Industry: Conveyor belts and work surfaces where a smooth screw head prevents food traps.
• Architectural Handrails: Securing joints in stainless steel railings for a seamless touch.
• Consumer Electronics: Exterior casing assembly for high-value devices.

Frequently Asked Questions

What is the standard angle for these countersunk screws?

Our metric DIN 7991 / ISO 10642 screws have a standard 90-degree head angle. This is important because some aerospace or imperial (inch) screws use 82-degree or 100-degree angles. Always ensure your countersink drill bit matches the 90-degree angle of the screw for a perfect fit.

How do I prevent stainless countersunk screws from seizing?

Stainless steel threads are prone to "galling" (cold welding), and countersunk screws are particularly susceptible because the large cone-shaped head creates significant friction against the hole as it tightens. To prevent seizing, we strongly recommend applying a high-quality anti-seize lubricant paste to the threads and tightening the screw slowly by hand.

What if my countersink hole is too deep or too shallow?

Precision is key for countersunk screws. If the hole is too shallow, the head will protrude, creating a snag hazard. If it is too deep, the head will sink below the surface, which can collect dirt and water, leading to corrosion issues. We recommend using a depth-stop countersink bit to ensure consistent flush mounting across all holes.