Hex Socket Button Head Cap Screw

Hex Socket Button Head Cap Screw — Product Introduction

The hex socket button head cap screw is a fastener with a low-profile button (rounded flat) head featuring a recessed hex socket on top. It is tightened using an hex key (Allen wrench). The smooth, low-profile head sits above the joined surface after installation without protruding sharply, offering a clean appearance and compact profile. The product is manufactured to GB/T 70.2, with thread sizes from M3 to M20, property classes including 8.8, 10.9, and 12.9 for carbon and alloy steels, as well as stainless steel A2-70 and A4-80. It is widely used for fastening in machinery and equipment, automobiles, electronics, furniture, and molds.

I. Product Features

• Low-profile button head: The dome-shaped head is lower than a standard pan head, occupying less space after installation and presenting a clean, smooth profile.
• Hex socket drive: The top of the head features a standard hex socket, driven with an hex key for even load distribution, minimal risk of cam-out, and suitability for confined spaces.
• Complete range of sizes and classes: Thread sizes M3 to M20, carbon steel property classes 8.8, 10.9, and 12.9, stainless steel A2-70 and A4-80 among others.
• Wide variety of materials and finishes: Carbon steel, alloy steel, stainless steel; surface treatments include blackening, zinc plating, Dacromet, and Geomet.
• Compatible with countersunk holes: When the joined part is machined with a matching countersunk bore, the button head can be partially or fully recessed for a flush surface.

II. Product Advantages

• Aesthetic and snag-free: The smooth head has no sharp edges, reducing the risk of injury to operators or damage to adjacent components, ideal for equipment with appearance requirements.
• Compact installation space: The low-profile head suits space-constrained locations, and the hex key can be applied from above or the side.
• High torque capacity: The hex socket’s large bearing area accepts high tightening torque, making it suitable for high-strength connections.
• Reliable anti-loosening: Combined with thread-locking adhesive or self-locking nuts, it meets anti-loosening requirements in vibrating conditions.
• Excellent interchangeability: Highly standardized with unified dimensions, simplifying procurement and maintenance replacement.

III. Application Scope

• Machinery and equipment: Fastening of compact sections in machine tools, gearboxes, pumps, valves, and automated equipment.
• Automobiles and motorcycles: Engine, transmission, chassis, body accessories, and interior component connections.
• Electronics and home appliances: Chassis, cabinets, small appliances, instrument enclosures, and internal components.
• Furniture and decoration: Metal furniture, office furniture, display racks, and other applications requiring smooth, low-profile heads.
• Molds and tooling: Mold plates, jigs, and gauges requiring low-profile heads and hex socket drive.