Adopted by “The Association of Bolt and Nut Manufacturers of the
United States,” at their meeting in New York, December 11th, 1872.
| Diameter. | Size of Hole. | Thickness Wire Gauge. | Size of Bolt. | ||||
| 1⁄2 | 1⁄4 | No. | 18 | 3⁄16 | |||
| 5⁄8 | 5⁄16 | „ | 16 | 1⁄4 | |||
| 3⁄4 | 5⁄16 | „ | 16 | 1⁄4 | |||
| 7⁄8 | 3⁄8 | „ | 16 | 5⁄16 | |||
| 1 | 7⁄16 | „ | 14 | 3⁄8 | |||
| 1 | 1⁄4 | 1⁄2 | „ | 14 | 7⁄16 | ||
| 1 | 3⁄8 | 9⁄16 | „ | 12 | 1⁄2 | ||
| 1 | 1⁄2 | 5⁄8 | „ | 12 | 9⁄16 | ||
| 1 | 3⁄4 | 11⁄16 | „ | 10 | 5⁄8 | ||
| 2 | 13⁄16 | „ | 10 | 3⁄4 | |||
| 2 | 1⁄4 | 15⁄16 | „ | 9 | 7⁄8 | ||
| 2 | 1⁄2 | 1 | 1⁄16 | „ | 9 | 1 | |
| 2 | 3⁄4 | 1 | 1⁄4 | „ | 9 | 1 | 1⁄8 |
| 3 | 1 | 3⁄8 | „ | 9 | 1 | 1⁄4 | |
| 3 | 1⁄2 | 1 | 1⁄2 | „ | 9 | 1 | 3⁄8 |
Fig. 443.
The various forms of wrenches employed to screw nuts home or to remove them are represented in the following figures. [Fig. 443] represents what is known as a solid wrench, the width between the jaws a being an easy fit to the nuts across the flats. The opening between the jaws being at an angle to the body enables the wrench to be employed in a corner which would be too confined to receive a wrench in which the handle stood in a line with the jaws, because in that common form of wrench the position of the jaws relative to the handle would be the same whether the wrench be turned over or not, whereas with the jaws at an angle as in the figure, the wrench may be applied to the nut, rotating it a certain distance until its handle meet an abutting piece, flange, or other obstruction, and then turned over and the jaw embracing the same two sides of the nut the handle will be out of the way and may again operate the nut.
In some cases each end of the wrench is provided with jaws, those at one end standing at the same angle but being on the opposite side of the wrench.
Fig. 444.