How to say "flux" in Japanese

• 溶剤ようざいCommon
  nounCovers flux in the sense of a dissolving or cleaning agent, as in soldering and welding. Note that its primary meaning is 'solvent', so flux is only one of its senses.
  その液えきから溶剤ようざいを揮発きはつさせる。残のこるのは、香かおり成分せいぶんと植物しょくぶつワックスの塊かたまり。↗

  Vaporise the solvent from the liquid. What's left is the perfume component and a lump of vegetable wax.
• フラックス
  nounA loanword covering flux generally, especially the substance used in soldering and metallurgy. A straightforward choice when you want the technical term without choosing between the native options.
• 融剤ゆうざい
  nounThe precise term for a fusing agent: a substance mixed with a solid to lower its melting point, as in metallurgy and ceramics. Use this when that specific meaning is intended.
• 流束りゅうそく
  nounThe flux of physics and mathematics: the rate of flow of a quantity such as energy, particles, or a field through a surface. It is not used for the soldering or melting-agent senses.

For the chemistry/metallurgy sense choose 溶剤, 融剤, or 「フラックス」 depending on context, while 流束 is the word for flux in physics and mathematics; 「フラックス」 also covers that technical usage.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 溶剤ようざいsolvent
• フラックスflux
• 融剤ゆうざいflux (substance mixed with a solid in order to lower its melting point)
• 流束りゅうそくflux