Countersunk Head Rivets

A countersunk head rivet sits flush with the surrounding surface once fitted, making it the natural choice wherever a raised head would foul another part, catch on something moving past, or spoil an aerodynamic or hydrodynamic surface. Fitting one properly means countersinking the parent hole to match the rivet's head angle before riveting — if the countersink is too shallow the head stands proud, and if it's too deep the head sits below the surface and loses much of its shear strength across the joint.

The charts below give dimensional information on countersunk head rivets to BS641:1951, BS275:1927, and BS4260:1970. Dimensions shown are in inches; if you wish to convert to mm, please use our universal converter.

The solid rivet is the most widely used mechanical fastener in construction and manufacturing assembly. It offers the user these advantages:

A typical application for solid rivets would be within the structural parts of aircraft. Hundreds of thousands of solid rivets are used to put together the frame of a modern airplane. Such solid rivets come with rounded (universal) or countersunk heads. Typical aircraft rivets are composed of aluminum alloys, titanium, and nickel-based alloys.

The setting of solid rivet fasteners requires access from both sides of the structures. Solid rivets are driven using hydraulically driven squeezing tools or even handheld hammers. When only one side is available, blind rivets are more appropriate tools.

COUNTERSUNK HEAD RIVET DIMENSIONS - BS641: 1951 TABLE 5 - 60° COUNTERSUNK HEAD

Head Diameter A=1.75D, Head Depth B=0.65D, Setting Allowance S=0.609D

The British Standard does not specify tolerances for Head Diameter & Depth, Angle of Countersink or Shank Length. *These Diameters are not specifically denoted in BS 641 Table 5.

COUNTERSUNK HEAD RIVET DIMENSIONS - BS641: 1951 TABLE 6 - 90° COUNTERSUNK HEAD

Head Diameter A=2D, Head Depth B=0.5D, Setting Allowance S=0.667D

The British Standard does not specify tolerances for Head Diameter & Depth, Angle of Countersink or Shank Length. *These Diameters are not specifically denoted in BS 641 Table 6.

COUNTERSUNK HEAD RIVET DIMENSIONS - BS641: 1951 TABLE 7 - 120° COUNTERSUNK HEAD

Head Diameter A=2D, Head Depth B=0.29D, Setting Allowance S=0.249D

The British Standard does not specify tolerances for Head Diameter & Depth, Angle of Countersink or Shank Length. *These Diameters are not specifically denoted in BS 641 Table 7.

COUNTERSUNK HEAD RIVET DIMENSIONS - BS275: 1927 TABLE 2, FIGURE 9 - FLAT 45° COUNTERSUNK HEAD

Head Diameter A=1.5D, Head Depth B=0.604D, Setting Allowance S=0.352D

The British Standard does not specify tolerances for Head Diameter, Angle of Countersink or Shank Length.

COUNTERSUNK HEAD RIVET DIMENSIONS - BS275: 1927 TABLE 2, FIGURE 7 - FLAT 60° COUNTERSUNK HEAD

Head Diameter A=1.5D, Head Depth B=0.433D, Setting Allowance S=0.253D

The British Standard does not specify tolerances for Head Diameter, Depth, & Angle of Countersink or Shank Length.

COUNTERSUNK HEAD RIVET DIMENSIONS - BS4620: 1970 TABLE 6 - 90° COUNTERSUNK HEAD

Head Diameter A=2D, Head Depth B=0.5D, Setting Allowance S=0.667D

The British Standard does not specify tolerances for Head Depth. There is no positive tolerance on Head Diameter, and no negative tolerance on Shank Length. The countersink angle can vary between 87½° and 92½°. *These diameters are not specifically denoted in BS 4620 Table 6.

COUNTERSUNK HEAD RIVET DIMENSIONS - BS4620: 1970 TABLE 7.1 - 60° COUNTERSUNK HEAD

Head Diameter A=1.5D, Head Depth B=0.43D, Setting Allowance S=0.253D

The British Standard does not specify tolerances for Head Depth. The countersink angle can vary between 57½° and 62½°.

RELATED PAGES

• Raised Countersunk Head Rivets
• Mushroom Head Rivets
• Round Head Rivets
• Engineering Glossary — Rivet

FREQUENTLY ASKED QUESTIONS

What's the difference between a countersunk and raised countersunk rivet?

A standard countersunk rivet sits completely flush with the surface. A raised countersunk (also called an "oval countersunk") rivet has a small domed profile above the countersunk base, giving a bit more head strength and a slightly decorative finish while still countersinking into the surface. See our Raised Countersunk Head Rivets chart for dimensions.

How do I choose the right rivet diameter and length?

Diameter is chosen based on the load and the thickness of material being joined; length is chosen so that enough shank protrudes to form a full, properly formed tail once set, typically around 1.5 times the rivet diameter beyond the joint thickness as a starting point — always check the specific rivet manufacturer's guidance for your application.

Do countersunk rivets need a specific countersink angle in the parent material?

Yes — the countersink angle machined into the parent material must match the rivet head's angle (commonly 90° or 120° depending on the standard) so the head seats flush and evenly, rather than rocking or standing proud on one edge.