China Countersunk Bolt Manufacturer, Supplier, Factory

Comprehensive Guide to Countersunk Bolts

When selecting fasteners for projects requiring a flush surface finish, countersunk bolts are often the optimal choice. These specialized bolts feature a conical head that sits perfectly within a countersunk hole, ensuring no protrusion above the material surface. This design is crucial in applications where aerodynamics, safety, or aesthetics are priorities, such as in aerospace components, machinery, and furniture assembly. While countersunk bolts serve a specific purpose, other bolt types like the Hexagon Head Bolt are better suited for high-torque applications, and the Hexagon Head Flange Bolt provides a built-in washer for distributed load. For more traditional or historical applications, the Square Head Bolt offers excellent grip for wrenches, whereas the Round Head Bolt is selected for its low-profile, non-countersunk dome head.

The defining feature of any Countersunk Bolt is its head angle, typically standardized at 82° or 90°, which must match the countersunk hole for a perfect fit. This precise engineering prevents the bolt head from snagging on other objects and provides a smooth, continuous surface. Countersunk Bolts are manufactured from various materials to meet different environmental and strength requirements. Common materials include carbon steel, stainless steel for corrosion resistance, and alloy steel for high-strength applications. They can also be plated with zinc, chrome, or other coatings to enhance durability and appearance. The installation of a Countersunk Bolt requires a compatible countersunk hole, which is often prepared using specialized drill bits and tools to achieve the correct angle and depth.

Countersunk Bolt Standard Specifications

• Head Types: Flat Countersunk, Oval Countersunk
• Common Standards: ASME B18.3, ISO 10642, DIN 7991
• Drive Types: Phillips, Slotted, Socket (Hex), Pozidriv
• Common Finishes: Zinc Plated, Black Oxide, Hot-Dip Galvanized, Passivated

Detailed Material and Mechanical Properties

Standard Size Chart (ASME B18.3)