Glass vs Ceramic Fuses, What's the Difference?

  • Searching through the tremendous amount of fuses available at Digikey can be a bit overwhelming. We have several parameters to select from including glass body or ceramic body fuses, let’s take a look at a common size 3AB, 3AG, 1/4" x 1-1/4" glass and ceramic fuse.

  • You might ask yourself, “What’s the difference, should I select the glass one or the ceramic, does it matter?” Look at the comparison between these two fuses (note the specifications are the same, 1 amp, 250VAC, fast blow) but one is glass the other is ceramic.


  • Note the breaking capacity at rated voltage. The ceramic fuse is much higher at 100 amps compared to 35 amps for the glass fuse with the same AC voltage rating. The breaking capacity is the maximum current that can safely be interrupted by the fuse. A ceramic fuse offers better thermal and arc protection during a high current episode compared to a glass fuse with the same specifications.

  • When choosing a fuse, glass is a good option for applications where the probability of a high current episode isn’t likely to occur (compare the breaking capacity to the potential current the fuse may be subjected to), they also offer the ability to physically see if the filament is damaged. Ceramic has a higher breaking capacity offering a greater level of thermal and arc protection better suited for applications where high current episodes may occur.

  • Can I switch one for the other?
    With all specifications and safety ratings the same you should be able to go from glass to ceramic but I wouldn’t recommend replacing ceramic with glass.

Important note: The fuses mentioned here are your standard glass and ceramic cylindrical fuses used in hundreds of household goods and electronic devices, these are not HRC (High Rupture Capacity) fuses used in high power equipment and multimeters even though some may look similar. Never replace an HRC fuse with one of these common glass or ceramic fuses. Search our specailty fuses when looking for high power and multimeter fuse options.