Greases

Choosing a grease: the thickener decides, not the price

Grease selection goes wrong more often than oil selection, because two greases can look identical, cost the same and carry similar temperature claims while being chemically incompatible. Four questions settle almost every case.

One: NLGI consistency

• NLGI 00 and 0 — semi-fluid, for centralised lubrication systems and gearboxes that specify a fluid grease (PREMUS AUTO, PREMUS COT). These pump through long lines and cold mornings where a stiffer grease would not reach the far points.
• NLGI 1 — softer, better pumpability in long lines and low temperatures (INNOVA SYN/LT 1, PREMUS LI-CA 1).
• NLGI 2 — the standard for bearings and general machinery. Where a manual says only “grease” with no further detail, this is what it means.
• NLGI 3 — stiffer, for vertical shafts and points where retention matters and a softer grease would be thrown out (PREMUS LI 3, LEP 3, CA 3).

In sustained Iraqi heat a grade stiffer can help retention on open or poorly sealed points — but only where the system can still pump it. On a centralised system, never go stiffer than the manufacturer allows.

Two: the thickener

This is the decision that actually matters, and it is the one most often ignored:

• Lithium (PREMUS LI, PREMUS LEP) — the general-purpose thickener, with good mechanical and thermal stability. LEP adds extreme-pressure additives for shock and heavy load.
• Lithium complex (INNOVA COMPLEX, COMPLEX HD, SYNCOMPLEX/TF) — a much higher dropping point, so it holds where an ordinary lithium grease softens and runs out. The right answer for hot, heavily loaded points.
• Anhydrous calcium (PREMUS CA, PREMUS LI-FREE EP) — water resistance and adhesion. Choose it where standing water or washdown is the problem rather than heat.
• Calcium sulphonate complex (INNOVA COMPLEX/WTR) — the severe-duty answer: shock loading combined with water, dust and mud, plus outstanding anti-rust protection.
• Mixed lithium-calcium soap (PREMUS LI-CA) — insoluble in water with good thermal and mechanical stability. The practical all-rounder for heavy-duty off-road and industrial points.
• Polyurea (INNOVA POLY) — long service life and strong oxidation resistance at high temperature and pressure. Electric motor bearings and sealed points that will not be re-greased often.
• Bentonite clay (PREMUS BNT) — a non-melting thickener. For constant high heat and for repeated heating and cooling cycles that break soap-thickened greases down.
• Synthetic lithium (INNOVA SYN/LT) — low temperature and long service: machine tool spindles, small electric motors, robots and control equipment.

Three: the additive for the specific problem

• Molybdenum disulphide (MoS2) — PREMUS MLB, INNOVA COMPLEX/MLB. A solid lubricant that keeps working under very high load, shock loading and slow oscillating movement, and gives some protection if a point briefly runs dry. The standard choice for pins and bushes on excavators, loaders and dozers.
• Graphite — PREMUS GRF. Dry lubrication for points hot enough to drive the oil carrier off.
• PTFE — INNOVA SYNCOMPLEX/TF. Very high operating temperature, drum and oven applications.
• Tacky and water-resistant — PREMUS CY-WR/OG. Wire ropes, open gears, slideways, crane chassis and exposed points that must not wash off.
• Biodegradable — INNOVA CY/BIO, PREMUS ECO BIO COTTON. Marine work, environmentally sensitive sites, and agricultural equipment where grease reaches soil or crop.

Four: what Iraqi conditions change

• Heat. A grease that performs well in Europe can soften and leak out here. For hot points prefer lithium complex, polyurea or bentonite over ordinary lithium.
• Dust. On exposed pins, greasing generously is usually better than sparingly, because fresh grease purges abrasive out of the joint. But wipe every fitting before connecting and keep the gun nozzle capped — a dirty nozzle injects sand straight into the bearing, which is worse than no grease at all.
• Water. After seasonal rain and washdowns, water resistance matters more than the temperature range on the datasheet.
• Do not mix thickeners. Two good greases with different thickeners can be incompatible, and the mixture can soften and run out of the joint even though each product alone performs well. When changing thickener type, purge the point until only the new grease emerges.

Frequently asked questions

Not sure which product a vehicle, machine or fleet needs? Try the Cyclon oil selector, or send us the details and we will specify it in writing.