App note from Littlefuse intended to give an overview of the available systems, the strength and weaknesses of each combination, and to help the designer in the selection of the best fuse and holder solution for each application. Link here (PDF)
5×20 mm fuses continue to be the most widely used components for primary and secondary circuit protection. Although the technology is over 50 years old, the current usage is still estimated to be around 3 billion units per year. These fuses remain popular because:
• they are available anywhere in the world
• they are both reliable and inexpensive
• they offer breaking capacities up to 1500 A
Depending on the requirements and expectations of the designer, there are various methods of mounting the 5×20 mm fuses in the electronic appliance. These range from fuse clips, normally the cheapest option, to comprehensive shock safe fuse holder systems.