M18 Metric Thread

Below are the key dimensions for M18 metric threads: pitch, tap drill and clearance drill according to ISO 724:2023.
Step onto our M18 Metric Thread Page, your comprehensive reference for swift metrics on M18 metric threads. We've compiled a broad database for all common metric threads used in your parts, emphasising critical measurements such as thread pitch, tap drill, and clearance drill. This page serves as an all-in-one destination for engineers, machinists, and hobbyists seeking precise and dependable details.
All dimensions stated in are mm (millimetre)
The Major Diameter is the largest diameter on the thread and is measured from the thread crest to crest (peak of the thread).
This is the distance (mm) from one thread to the next, this can be measured from tip to tip or groove to groove. Pitch can also be defined as TPI, which stands for threads per inch.
Minor Diameter is the smallest diameter on the thread and is measured from the thread root to root (Bottom of the thread).
The angle between the thread faces. 60 degrees in the example above.
The thread will assemble when rotated clockwise. "righty tighty lefty loosely"
The thread will assemble when rotated counter-clockwise.
The pitch for an M18 thread is 2.5 mm.
The tap drill for an M18 thread is 15.5 mm.
The clearance drill for an M18 thread is 20 mm.