ME = Model Engineer Threads These come in 32,40 and 60 tpi sizes. Model Engineer nuts and bolts are rarely commercially available.

 

Actions Size Outside Dia Inch Tpi Pitch Inch Core Dia Inch Thread Depth Thou Tapping Drill Size Inch Tapping Drill mm Letter Or Number
1/8 0.125 32 0.031 20 0.093 2.4 3/32
5/32 0.156 32 0.031 20 0.124 3.2 1/8
3/16 0.188 32 0.031 20 0.156 4.0
7/32 0.219 32 0.031 20 0.187 4.7
1/4 0.250 32 0.031 0.210 20 0.213 5.5 3
9/32 0.281 32 0.031 0.241 20 0.246 6.3 D
5/16 0.313 32 0.031 0.273 20 0.277 7.1 J
3/8 0.375 32 0.031 0.335 20 0.339 8.6 R
7/16 0.438 32 0.031 0.398 20 0.404 10.2 Y
1/2 0.500 32 0.031 0.460 20 0.469 11.8 15/32
1/8 0.125 40 0.025 0.093 16 0.094 2.4 3/32
5/32 0.156 40 0.025 0.125 16 0.129 3.3 30
3/16 0.188 40 0.025 0.156 16 0.157 4.0 22
7/32 0.219 40 0.025 0.187 16 0.189 4.8 12
1/4 0.250 40 0.025 0.218 16 0.221 5.7 2
9/32 0.281 40 0.025 0.249 16 0.257 6.4 F
5/16 0.313 40 0.025 0.281 16 0.290 7.2 L
3/8 0.375 40 0.025 0.343 16 0.348 8.9 S
7/16 0.438 40 0.025 0.406 16 0.413 10.4 Z
1/2 0.500 40 0.025 0.468 16 0.469 12.0 15/32