What is a 5x20mm fuse? The 5x20mm fuse is a miniature cartridge fuse having a diameter of 5mm and a length of 20mm. This form factor is the most commonly used version worldwide. The 5x20 fuse is constructed with either a glass body or a ceramic body which can tolerate higher temperatures and offers a higher interrupting rating and voltage rating. The 5x20 fuse ratings are typically provided at both 125 volts AC and 250 volts AC. There are also 5x20mm fuse versions with voltage ratings up to 500 volts. The 5x20 fuse types are offered in fast acting, time lag or time delay versions and can be ordered with or without axial leads. The 5mm x 20mm fuse is typically built in accordance with UL 248-14 and CSA C22.2/No. 248.14 or IEC 60127-2 standards. The IEC 60127-2 5mmx20mm fuse series is offered in several versions:

IEC Designation	Type	Opening Speed	Breaking Capacity
IEC 127-2, Sheet I	Type F	Quick Acting	High
IEC 127-2, Sheet II	Type F	Quick Acting	Low
IEC 127-2, Sheet III	Type T	Time Lag	Low
IEC 127-2, Sheet V	Type T	Time Lag	High
IEC 127-2, Sheet VI	Type T	Time Lag	Enhanced

Littelfuse, Bussmann and Blue Sea all offer a version of the 5x20mm fuse.

Our 5x20mm fuse selection can be found by browsing our data sheet finder.

An Assortment of 5x20mm Fuses