In various fastening applications, riveting is often chosen because of its light weight & high firmness, low cost, easy installation, high durability and reliability. In order to assemble the parts correctly, hole preparation is critical. In this article, follow us to understand the rivet sizes and dimension details, including how to express and determine it, as well as the standard rivet hole size chart for reference.
The rivet sizes or dimensions commonly applied including the rivet diameters and lengths, which can be indicated in both imperial (inch) and metric (mm) series.
– Imperial: rivet diameters are commonly measured in 1/32-inch increments and the lengths are measured in 1/16-inch increments, expressed as “dash numbers”. For example, the “dash 3 dash 4” means a 3/32-inch diameter and 4/16 -inch length. Rivet lengths are also probably expressed in half sizes, and have a dash number such as -3.5 (7⁄32 inch) to indicate they are half-size.
– Metric: rivet diameters and lengths are measured in millimeters. Rivets with diameters between 2-20 mm and lengths between 5-50 mm are common for general use.
If the dimensions of rivets are not specified on the design drawing, you can determine the rivet size based on the following rules:
Minimum Diameter of Rivet Shank (D) = 3 x Thickness of the Thickest Sheet That is Being Joined
A=1.5 *D (For rivets of diameters of the rivet shank up to 20 mm)
Length of Rivet Shank (L) = S + Allowance (A)
A general rule is that the rivet should have a diameter of at least three times the thickness of the thickest sheet that is being joined. Please note that the value of D (diameter) is the minimum option of the rivet shank diameter, and the rivet shank must be longer than the thickness of all materials to be riveted, otherwise, there will be no allowance for fastening. According to the military standard, so the bucked counter head diameter of the rivet joint must be larger than 1.4 times the diameter of the shank. The allowance depends on the type of rivets and applications. Then how to determine the correct size of rivets?
For example, two pieces of the 0.060-inch sheets are to be riveted together. The proper diameter rivet would be 3 x 0.060=0.180 inches.
A 3/16” rivet (0.188 inches) should be used. The metal thickness is 0.060+0.060=0.12 inches, and 1.5D is 1.5 x 0.188 inch = 0.282 inches, so the total length would have to be 0.12 + 0.282=0.402 inches for the rivet.
When you calculated the diameter of the rivet, you can choose a standard rivet size a little larger than it based on the following chart.
The rivet diameter is related to the drill required to make a hole through which the rivet pass. After determining the rivet size and putting the sheets, the hole size must be marked for drilling. So, it’s important to know the rivet hole size before the installation. Generally, the actual diameter of the rivet is slightly smaller than that of the hole need to be drilled. Ideally, a rivet should be placed in a hole which is 4-6 thousandths of an inch larger in diameter. This allows the rivet to be easily and fully inserted, then make the rivet expand, tightly fill the gap and maximize strength.
Standard Rivet Hole Sizes & Drill Sizes