Translation guide
A fluid used to remove heat from a system, such as an engine, reactor, or cutting tool.
The liquid that circulates in a car engine or similar system to prevent overheating.
Literally 'cooling water'. The most common term for engine coolant, especially in cars.
冷却水の量を確認してください。
Please check the coolant level.
エンジンの冷却水が漏れている。
The engine coolant is leaking.
Loanword from English. Used in technical contexts, often for industrial coolants or in product names.
このクーラントは希釈して使います。
This coolant is used after dilution.
Antifreeze. Specifically refers to the coolant's antifreeze properties, often used in winter contexts.
冬になる前に不凍液を交換した。
I changed the antifreeze before winter.
Fluid used to lubricate and cool cutting tools during metalworking or machining.
Cutting oil. The standard term for coolant/lubricant in machining.
切削油を交換する必要がある。
The cutting oil needs to be changed.
Also used in machining contexts, especially for water-soluble coolants.
Fluid circulated through a nuclear reactor to transfer heat.
General term for reactor coolant, often used for substances like liquid sodium or water.
原子炉の冷却材として液体ナトリウムが使われる。
Liquid sodium is used as a coolant in nuclear reactors.
冷却水 is the everyday term for engine coolant. クーラント is a loanword used in technical or industrial contexts, and may sound more specialized.
Coolant for air conditioners or refrigerators is called 冷媒 (れいばい), not 冷却水 or クーラント.
冷却水の量を確認してください。
Check the coolant level.
冷却水を交換する必要があります。
The coolant needs to be replaced.
We use water-soluble coolant.