UL94-V0 and G9 are the two most-quoted grades in fuse tube selection, but they measure different things.

UL94-V0 (flame rating): describes a material's self-extinguishing ability after ignition — the highest common vertical-burn class: quick extinguishing with no flaming drips. For fuse tubes, V0 means the tube will not sustain burning during abnormal interruption.

G9 (arc resistance): grades a material's ability to withstand arc exposure on its surface; higher is stronger. G9 is a high arc grade suited to high-energy DC scenarios such as charging piles and EVs, where the surface must resist carbonized conductive paths.

One grade covers flame, the other arc — together they define tube reliability under extreme duty. Zhongfu melamine tubes meet UL94-V0 plus high-grade arc resistance; ask us for the datasheet.