# What diameter is a 2 56 screw

## Tips

Example: 3/8 "- 16 x 1/2" hex bolt
3/8 = outer thread diameter 9.53 mm
16 = number of threads on 1 inch (25.40 mm) length
1/2 = length of the screw from the head 12.70 mm

Example: 3/8 "- 24 x 1/2" hex bolt
3/8 = outer thread diameter 9.53 mm
24 = number of threads on 1 inch (25.40 mm) length
1/2 = length of the screw from the head

Wrench sizes and thread diameters for hexagon
Inch screws and nuts

in inches in millimeters screw nut

1/4                                   6,350                             7/16                    7/16
5/16                                 7,935                             1/2                      1/2
3/8                                  9,525                              9/16                     9/16
7/16                               11,113                             5/8                     11/16
1/2                                12,700                              3/4                       3/4
9/16                              14,288                             13/16                    7/8
5/8                                15,875                             15/16                  15/16
3/4                                19,050                             1 1/8                   1 1/8
7/8                                22,225                             1 5/16                 1 5/16
1                                   25,400                             1 1/2                   1 1/2

UNC thread No. 1 - 12

in millimeters core hole in mm inches

1 - 64 UNC 1.854 1.50 64
2 - 56 UNC 2.184 1.78 56
3 - 48 UNC 2.515 2.05 48
4 - 40 UNC 2.845 2.27 40
5 - 40 UNC 3.175 2.59 40
6 - 32 UNC 3.505 2.77 32
8-32 UNC 4.166 3.42 32
10-24 UNC 4.826 3.82 24
12-24 UNC 5.486 4.47 24

UNF thread No. 0 - 12