Bolt with nut

Metric coarse thread Metric fine thread specifications Standard diameter maximum and minimum specifications Standard diameter maximum and minimum specifications Standard diameter maximum and minimum M1.0* 0.250.750.7850.729M1.0 * 0.20.80.8210.783M15 * 1.01414.35313.917M1.1 * 0.250.850.8850.829M1.1 * 0.20.90.9210.883M16 * 1.514.514.67614.376M1.2 * 0.250.950.9850.929M1.2 * 0.211.0210.983M16 * 1.01515.15314.917M1.4 * 0.31.11.142 1.075M1.4 * 0.21.21.221 1.183M17 * 1.515.515.67615.376M1.6 * 0.351.251.3211.221M1.6 * 0.21.41.4211.383M17 * 1.01616.15315.917M1.7 * 0.351.351.4211.321M1.7 * 0.21.451.51.46M18 * 2.01616.2115.835M1.8 * 0.351.451.5211.421M1.8 * 0.21.61.6211.583M18 * 1.516.516.67616.376M2.0 * 0.41.61.6791.567M2.0 * 0.251.751.7851.729M18 * 1.01717.15316.917M2.2 * 0.451.751.8881.713M2.2 * 0.251.951.9851.929M20 * 2.01818.2117.835M2.3 * 0.41.91.9791.867M2.3 * 0.252.052.0612.001M20 * 1.518.518.67618.376M2.5 * 0.452.12.1382.013M2.5 * 0.352.22.2212.121M20 * 1.01919.15318.917M2.6 * 0.452.22.2382.113M2.5 * 0.352.22.2462.186M22 * 2.02020.2119.835M3.0 * 0.52.52.5992.459M3.0 * 0.352.72.7212.621M22 * 1.520.520.67620.376M3.0 * 0.62.42.442.28M3.5 * 0.353.23.2213.12122 * 1.02121.15320.917M3.5 * 0.62.93.012.85M4.0 * 0.53.53.5993.459M24 * 2.02222.2121.835M4.0 * 0.73.83.4223.242M4.5 * 0.544.0993.959M24 * 1.522.522.67622.376M4.0 * 0.753.253.3263.106M5.0 * 0.54.54.5994.459M24 * 1.02323.15322.917M4.5 * 0.73.83.8783.688M5.5 * 0.555.0994.959M25 * 2.02323.2122.835M5 * 0.84.24.3344.134M6.0 * 0.755.35.3785.188M25 * 1.523.523.67623.376M5 * 0.94.14.173 .98M6.0 * 0.55.55.555.4M25 * 1.02424.15323.917M6 * 1.055.1534.917M7.0 * 0.756.36.3786.188M26 * 1.524.524.67624.876M7 * 1.066.1535.917M7.0 * 0.56.56.556.4M27 * 2.02525.2124.735M8 * 1.256.86.9126.647M8.0 * 177.1536.917M27 * 1.525.525.67625.376M9 * 1.257.87.9127.647M8.0 * 0.757.37.3787.188M27 * 1.02626.15325.735M10 * 1.58.58.6768.376M8.0 * 0.57.57.527.4M28 * 2.02626.2125.835M11 * 1.59.59.6769.376M9.0 * 188.1537.917M28 * 1.52626.67626.376M12 * 1.7510.310.2410.11M9.0 * 0.758.38.3788.188M28 * 1.02727.15326.917M14 * 2.01212.2111.84M10 * 1.258.88.9128.647M30 * 3.02727.25226.752M16 * 2.01414.2113.84M10 * 1.099.1538.917M30 * 2.02828.2127.835M18 * 2.51515.14415.29M10 * 0.759.39.3789.188M30 * 1.02828.67628.376M20 * 2.51717.74417.29M10 * 0.59.59.529.4M32 * 2.03029.15328.917M22 * 2.51919.74419.29M11 * 1.01010.1539.917M32 * 1.53030.2129.835M24 * 3.02121.25220.75M11 * 0.7510.310.37810.19M33 * 3.03030.67630.376M27 * 3.02424.25223.75M12 * 1.510.510.67610.38M33 * 2.03130.25229.752M30 * 3.526.526.77126.21M12 * 1.2510.810.91210.65M33 * 1.531.531.2130.835 M12 * 11111.15310.92M35 * 1.533.533.67631.376 M12 * 0.511.511.52311.4M36 * 3.03333.25232.752 M14 * 0.512.512.67612.38M36 * 2.03434.2133.835 M14 * 1.01313.15312.92M36 * 1.53434.67634.376 M15 * 1.5013.513.67613.38 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

Additional note for Floor 2: When choosing a drill bit for drilling low-depth holes, attention should also be paid to the material of the component. For drills used on brittle materials such as gray cast iron, choose a smaller point size ； For drills on plastic materials, a larger size can be chosen. During the threading process, there is cutting, as well as material buildup.

Just look it up in the machining manual

Should we refer to the standard specifications of the drill bit?

I haven’t done it in ages; I’ve almost forgotten everything!

For such a simple question, you need to learn to use reference books in the future

It’s listed in mechanical workers’ cutting manuals, and there are also posts on forums regarding the diameter of the threaded bottom hole

Please consult the mechanical manual; there are many references available.

There is a rough formula for coarse-threaded threads: the diameter of the thread bottom hole equals the nominal diameter minus the pitch.