Maɓalli na 0.4mm yana nufin cewa diamita na ramin bututun shine 0.4mm. Daga cikin bututun da ke fesa ruwa, ramin feshin 0.4mm diamita na iya samar da sifa mai kama da hazo, wanda kuma ake kira bututun ƙarfe.

The diamita na fesa rami na bututun ƙarfe yana da babban dangantaka tare da barbashi size of fesa ruwa. Misali, lokacin da diamita na ramin feshin bai wuce 0.6mm ba, feshin feshin shine hazo. Lokacin da diamita na ramin fesawa bai wuce 2mm ba, nau’in feshin gaba ɗaya kamar ruwan sama ne. Lokacin da diamita na ramin fesawa bai wuce 5mm ba, ƙirar feshin gabaɗaya tana kama da ruwan sama mai matsakaici, da sauransu, mafi girman ramin ramin feshin, mafi girman adadin kwararar feshin, kuma mafi girman faɗuwar digo.