| 1.9439 | = pitch of rivets. |
| .8750 | = diameter of rivet. |
| 1.0689 | = distance in inches between the rivets. |
If now we multiply this distance between the rivets by the thickness of the plate, we shall get the area of the plate that is left between the rivet holes, thus:
| 1.0689 | = width of plate between rivets. | ||||||||
| .5625 | = thickness of plate. | ||||||||
| 53445 | |||||||||
| 21378 | |||||||||
| 64134 | |||||||||
| 53445 | |||||||||
| Area of plate between rivets = | .60125625 | ||||||||
Here then we find the area of plate left between the rivet holes to be 6.01 square inches, and as the area of the rivet is 6.01 square inches, the two are shown to be equal.
We may now place the various rivet diameters and the pitches that will make the rivet area and plate area in a single riveted joint equal in a table as follows:
Table of Rivet Diameters and Pitches for Single Riveted Lap Joints.
| Thick- ness of Plate. | Diameter of Rivet. | Pitch. | |||
| 1⁄4 | 1⁄2 | 1 | 1⁄4 | ||
| 5⁄16 | 5⁄8 | 1 | 5⁄8 | ||
| 3⁄8 | 11⁄16 | 1 | 11⁄16 | ||
| 7⁄16 | 3⁄4 | 1 | 3⁄4 | ||
| 1⁄2 | 3⁄4 | 1 | 5⁄8 | ||
| 9⁄16 | 7⁄8 | 2 | |||
| 5⁄8 | 7⁄8 | 1 | 7⁄8 | ||
| 11⁄16 | 7⁄8 | 1 | 3⁄4 | ||
| 3⁄4 | 1 | .. | |||
| 13⁄16 | 1 | 2 | |||
| 7⁄8 | 1 | 1 | 1⁄8 | ||
| 15⁄16 | 1 | 1⁄8 | 2 | 1⁄8 | |
| 1 | 1 | 1⁄8 | 2 | 1⁄8 | |
| 1 | 1⁄16 | 1 | 1⁄8 | 2 | 1⁄8 |
| 1 | 1⁄8 | 1 | 3⁄16 | 2 | 1⁄4 |
| 1 | 1⁄4 | 1 | 3⁄16 | 2 | 1⁄8 |
The rivets in double riveted lap joints, and in butt strap joints having a single cover, are spaced alike, because in both cases there are two rivets in one pitch, and the rivets are in single shear.
As there are two rivets in one pitch (instead of only one as in a single riveted joint), therefore the percentage of rivet section is doubled, and the plate section must therefore be doubled if the plate and rivet sections are to be made equal, and the rule for finding the required pitch is as follows:
Rule.—To the amount of rivet area in one pitch, divided by the thickness of the plate, add the diameter of the rivet.