Grease Guide
AP3 Grease Specification and Application Guide
AP3 grease is an all-purpose, NLGI grade 3 lithium grease used widely on construction sites and in workshops across India. “AP” stands for all-purpose and “3” is the NLGI consistency grade. This guide covers its specifications, how to read a supplier’s datasheet, where it is applied, and how it relates to the MP3 grade buyers often confuse it with.
What AP3 grease is
AP3 is a firm (NLGI 3) lithium-soap grease with EP and anti-wear additives, formulated for general-purpose lubrication across mixed equipment. The firm grade is the key feature: it stays in place on exposed pins, threads and bearings without slumping in summer heat, which is why it is preferred on Indian sites over softer NLGI 2 greases for exposed points.
AP3 grease specification
| Property | Typical AP3 value | Why it matters |
|---|---|---|
| Thickener | Lithium soap | Good all-round stability and heat tolerance |
| NLGI grade | 3 | Firm, resists slumping and wash-off |
| Base oil viscosity (40°C) | 150–220 cSt | Load-carrying for medium-speed bearings |
| Dropping point | ≥185°C | Heat at which grease starts to flow, higher is better |
| Operating range | −20°C to 130°C | Suits Indian ambient and warm equipment |
| Water resistance | Good | Holds up to rain and washdown |
How to read an AP3 datasheet
Three numbers decide whether a grease is genuinely AP3-grade. First, the NLGI grade should read 3 (firm). Second, the dropping point should be 185°C or higher for a lithium grease, a low dropping point means it will run out when equipment warms up. Third, the base oil viscosity at 40°C should sit in the 150–220 cSt range for general bearing duty. Ask for a batch test certificate showing these values.
Where AP3 grease is applied
- Formwork pins, tie-rod threads and hinges
- General plain and rolling bearings
- Pulleys, shafts and exposed greasing points
- Site and earthmoving equipment chassis points
For exposed slow gears use open gear grease instead; for wet low-temperature points consider a calcium grease.
AP3 vs MP3 and branded grades
AP3 and MP3 are closely equivalent NLGI 3 multi-purpose lithium greases. Against branded product, AP3 matches the grade of Castrol APX at bulk pricing, see that comparison for the price and spec breakdown.
Common AP3 application mistakes
Two mistakes account for most AP3 problems on site. The first is using it where the temperature is too high. AP3 is a lithium grease rated to about 130°C continuous; on a point that runs hotter, it will eventually break down, and a higher-temperature grade or a different thickener is needed. The second is over-packing. Because AP3 is firm and stays put, crews sometimes keep pumping until grease bulges from every seal, which builds heat in sealed bearings and wastes product. Grease until fresh AP3 just shows at the seal, then stop.
A third, quieter mistake is contamination. AP3 is often used on exposed pins and threads in dusty conditions, so wipe the nipple and the surrounding area before greasing, grit pushed in with the grease does more damage than slightly delayed relubrication. On formwork threads, a light coat reapplied each cycle prevents seizure far better than a heavy coat left to collect dust.
Storage and shelf life
Keep AP3 grease in closed pails and drums, out of direct sun and away from water. Lithium greases store well for extended periods if sealed; check older stock for oil separation and stir it back in before use. Decant with a clean scoop or pump rather than dipping site tools into the drum, which contaminates the whole batch.
Why buy AP3 grease from KE
Krish Enterprises manufactures AP3 grease in Mumbai and supplies across the MMR in 500g/1kg cans, 18kg pails and 180kg drums, with a batch test certificate on request.
Frequently asked questions
What is AP3 grease?
An all-purpose, NLGI grade 3 lithium grease with EP additives for general-purpose lubrication.
What is the dropping point of AP3 grease?
Typically 185°C or higher for a lithium-based AP3 grease.
What is the difference between AP3 and MP3?
Very little in practice, both are NLGI 3 multi-purpose lithium greases, and the names are often used interchangeably.
What NLGI grade is AP3?
Grade 3, a firm consistency that resists slumping on exposed points.
Is AP3 grease waterproof?
Lithium-based AP3 has good water resistance for most outdoor and washdown duty. For points that sit in standing water at low temperature, a calcium grease resists washout better; choose by how wet and how warm the point runs.
What base oil viscosity should AP3 grease have?
Typically 150–220 cSt at 40°C, which suits general medium-speed bearing duty. Very high-speed bearings prefer a lower viscosity; heavily loaded slow points prefer higher. The datasheet should state the value.
How long does AP3 grease last in storage?
Sealed lithium grease stores well for extended periods. Check older stock for oil separation, stir it back in if light, and discard if heavily separated. Keep drums closed, cool and out of direct sun.
Can AP3 grease be used on electric motor bearings?
For general motor bearings at normal temperature, an NLGI 3 lithium grease is widely used, but always follow the motor maker’s grease specification where one is given, as some motors call for a specific grade or quantity.
Related: AP3 vs Castrol APX · MP3 Grease Full Form