The sizes of flexible magnetic tape refer to the minimum and maximum sizes of the flexible magnetic tape when it is a roll format. The sizes of magnetic strip, which is a pre-cut flexible magnetic tape, are not stated below as there are an infinite number of lengths available.
Depth
The depth of flexible magnetic tape is the distance between its two magnetic faces, or between the adhesive and its magnetic face. The depth can range from 0.5mm (0.02″) to 5mm (0.2″).
The greater the depth of the flexible magnet, the greater the magnetic pull of the magnet. A magnetic tape with a depth of 5mm (0.2″) can hold 420g per cm2 of flexible magnetic tape, whereas a flexible magnetic tape with a depth of 0.5mm (0.02″) can only hold 17g per cm2.
A flexible magnetic tape with a large magnetic pull is useful for a flexible magnetic tape with an adhesive on one of its faces. This is because an adhesive-backed flexible magnetic tape allows the magnet to hold onto non-magnetic materials, such as a photograph. This requires a large magnetic pull to attach itself to a ferromagnetic material as well as holding onto the non-magnetic object.
Length
The length of a flexible magnetic tape refers to the amount of magnetic tape on the roll and can range from 76.2mm (3″) to 620m (2034ft 1″). The 620m (2034ft 1″) tape is the most suitable variety for industrial use. The range available allows you to cut the flexible magnetic tape to the length you need.
Width
The width of a flexible magnetic tape is the distance between its two widest points. It ranges from 8mm (0.3″) to 76.2mm (3″).
Flexible magnetic tape with a larger width would be beneficial for creating fridge magnets as the magnet will need to cover a large surface area of the photograph, for example, to hold it onto the fridge.
To summarise, when purchasing flexible magnetic tape, the key thing to look out for is the length and depth. The length of tape has the greatest size variant so if you need a long tape then any flexible magnetic tape with a length over 10m (393″) would be adequate.
Tape with a depth of over 2mm (0.08″) will allow the magnet to hold ferromagnetic objects as well as its own weight for example, photographs.