Metalworking Fluids Explained: Castrol Hysol, Alusol, Honilo and Variocut

Metalworking fluid selection starts with one question: are you running a neat oil or a water mix fluid? Everything else follows from that.

Water mix fluids

Water mix fluids are supplied as a concentrate and diluted on site. Water is an excellent coolant, so these suit high speed operations where heat is the limiting factor: general machining, turning, and most grinding.

Hysol covers general water mix machining and grinding. Alusol is formulated for aluminium alloys, which matter because some general purpose fluids will stain or corrode aluminium.

Water mix fluids need managing. Check concentration with a refractometer rather than by eye, keep the tank aerated, and watch for the smell that tells you bacterial growth has taken hold. A neglected sump is a health issue as well as a quality one.

Neat cutting oils

Neat oils are used undiluted. They lubricate better than water mix fluids and cool less, so they suit heavy, slow, high pressure operations where surface finish and tool life matter more than heat removal.

Honilo is the honing and fine machining range, where swarf settling and finish are critical. Variocut covers general neat cutting for turning, drilling and grinding.

Forming is a separate category

Pressing, stamping and deep drawing are not cutting operations and need forming lubricants rather than cutting fluids. That is what the iloform range is for.

Do not forget corrosion protection

Freshly machined steel will start to corrode quickly, particularly if it is going into storage or transit. Rustilo corrosion preventives are the usual answer between machining and despatch.

Tell us the material, the operation and the machine, and we will narrow the options. Request a quote.