DIN 7991 Hexagon Socket Countersunk Head Cap Screw

This is a DIN 7991 Hexagon Socket Countersunk Head Cap Screw produced by JINGHONG. This product is strictly manufactured in accordance with the German standard DIN 7991. The main body is made of high-quality alloy steel or medium carbon steel, and undergoes quenching and tempering heat treatment to reach the Gr10.9 high-strength standard. The surface is treated with blue-white zinc. Its structural feature is a full-thread design. The head is a 90° conical countersunk type, and there is an internal hexagonal driving hole at the top. During installation, the screw head can fully sink into the pre-drilled countersunk holes on the surface of the workpiece, achieving a flush surface.

Product Feature

Ultra-high mechanical strength (Gr10.9 grade): The Gr10.9 grade belongs to high-strength fasteners, with a tensile strength of up to 1000 MPa and a yield strength of 900 MPa. Compared to ordinary 8.8 grade screws, it can withstand higher static loads and alternating loads, significantly enhancing its resistance to deformation and fatigue, making it highly suitable for connections in heavy-load structures.

Excellent surface anti-corrosion and environmental protection (blue-white zinc): The blue-white zinc surface treatment involves electroplating a layer of zinc on the steel surface and combining it with an environmentally friendly trivalent chromium blue-white passivation process to form a dense protective film. It not only presents a uniform, clean blue-white matte appearance, with salt spray tests typically lasting 48-96 hours, but also fully complies with international environmental protection regulations such as RoHS, effectively avoiding the toxicity risk of hexavalent chromium.

Perfect surface flatness and aesthetics: The 90° countersunk design ensures that it can be perfectly flush with the installation surface after tightening, without protruding or interfering. This design not only guarantees the tightness of the connection but also significantly enhances the appearance neatness and visual texture of the equipment or product, and is often used in precision equipment or structural components with appearance requirements.

Efficient torque transmission and adaptability to narrow spaces: The internal hexagon drive design provides six force-bearing surfaces, with high torque transmission efficiency and low slippage (slipping). Compared to external hexagon bolts, it is more suitable for space-constrained, tool-operated environments in precision assembly, with convenient disassembly and assembly and certain anti-theft properties.

Strict quality certification: Jinghong fasteners, as a professional manufacturer, has products that have passed ISO 9001 quality management system and TS16949 automotive industry quality management system certifications, ensuring high precision and consistency from raw materials to finished products.

Our Strength

·  Direct from manufacturer to customer, On time delivery

·  Completely fastener products,offers one - stop shopping service.

·  High quality and competitive price, saving your cost.

·  Product complies with iso9001 and ts16949 certification

·  After shippment, we will offer the Material report and Test report.

Product Application

This high-strength countersunk hexagonal screw is widely used in fields where strength, appearance and anti-corrosion are all of high requirements:Automobile and rail transportation: The chassis suspension system of automobiles, the brackets around the engine, the hub bolts and the train bogies that need to bear high loads and have a smooth surface.Mechanical and mold manufacturing: The fixed plates of large reducers, heavy machine tool fixtures, injection/molding molds, etc., which require high strength and anti-interference.New energy and outdoor equipment: The connection of wind power equipment, photovoltaic brackets, outdoor power equipment, etc., which need to withstand wind loads and alternating loads, and are also exposed to salt spray corrosion environments.Precision instruments and electronic equipment: The internal structure connections of precision measuring instruments, high-end servo motor housings, etc., which require a smooth surface to ensure airtightness or appearance texture.

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Q: Are you trading company or manufacturer ?

A: We are factory

Q: How long is your delivery time?

A: Generally it is 2-5 days if the goods are in stock. or it takes around 20 days if the goods are not in stock, certainly,it is according to your quantity.

Q: Do u do Non-standard Fasteners,and How about the OEM/ODM?

A:Yes,we do Non-standard Fasteners,OEM/ODM as well,and we have 20 years more experience in this line.We have complete production line, R&D Center. Pre-sales and after-sales support. Let u no worries about the quality.

Q: Do you provide samples ? is it free or extra ?

A: Yes, we could offer the sample for free,but u need charge the freight at the first time.

Q:Do you sell little quantity,like few hundred and few thousand?

A: It depends on the stock. if we have ,that's ok. if not,it needs MOQ.