A cable gland has various dimensions, namely:

• The thread connection and corresponding cable diameter
• The thread length

Read more below about the different dimensions within these two characteristics.

The thread connection is indicated with an M-number, which each correspond to a cable diameter:

• M12 – cable diameter of 3 – 6.5 mm
• M16 – cable diameter of 5 – 10 mm
• M20 – cable diameter of 8 – 13 mm
• M25 – cable diameter of 11 – 17 mm
• M32 – cable diameter of 15 – 21 mm
• M40 – cable diameter of 19 – 28 mm
• M50 – cable diameter of 27 – 35 mm
• M63 – cable diameter of 32 – 42 mm

The thread length is simply the length of the part of the cable gland with a thread. When the cable gland is used on an enclosure that is somewhat deeper, then a longer thread is desired. Our cable glands have one of the following five thread lengths:

• 8 millimeters
• 10 millimeters
• 12 millimeters
• 15 millimeters
• 18 millimeters

An M20 cable gland is a cable gland that is suitable for cables with a cable diameter of minimum 8 and maximum 13 millimeters. The M also indicates that this cable gland has a metric thread.

An M20 cable gland therefore has a cable diameter of minimum 8 and maximum 13 millimeters. The thread length varies.