A single-point automatic lubricator is the simplest form of automatic lubrication: one self-contained device, one lubrication point, weeks or months of unattended grease or oil delivery. For maintenance teams tired of chasing scattered bearings with a grease gun, these compact units deliver consistent lubrication at near-zero operating cost. This guide explains how they work, compares the four drive technologies, and gives you a practical selection framework.
Related: central lubrication system guide · auto greaser guide
What Is a Single-Point Automatic Lubricator?
A single-point automatic lubricator (often shortened to “single point lubricator” or just “automatic lubricator”) is a small reservoir — typically 60 to 250 cm³ of grease — with a drive mechanism that pushes lubricant out through a threaded outlet at a controlled rate. It screws directly into a standard grease fitting port on a bearing housing, or mounts remotely on a short tube run (typically up to 1.5 m) when the point is behind a guard or in a hot zone.
Once activated, the unit works unattended for its entire discharge period, which the user sets anywhere from 1 to 12 months depending on model. A transparent housing shows the remaining lubricant at a glance, so a quick visual check during normal rounds is all the supervision it needs. The result: the bearing receives small, frequent, consistent doses instead of the feast-and-famine cycle of monthly manual greasing — and plants typically see bearing life improve by 20–30% after switching.
Types: Spring-Driven vs Gas-Driven vs Electrochemical vs Electromechanical
Four drive technologies dominate the market. They differ in pressure, temperature tolerance, controllability, and cost of ownership.
Spring-Driven
A compressed coil spring acts on a piston, maintaining constant pressure — up to about 4 bar (65 PSI) — behind the grease. The discharge rate is set by a flow-control adjuster that changes the outlet orifice. Spring units need no battery or gas cartridge, tolerate a wide temperature band (−20°C to +100°C), handle NLGI 000 to NLGI 2 grease, and are fully refillable. With no electrical components they are inherently suitable for ATEX/hazardous areas. Typical reservoirs: 60cc, 237cc, 532cc for service intervals of roughly 1–6 months. Example: our spring-loaded single point lubricator.
Gas-Driven (Chemical Reaction)
Activating the unit (twist cap or pull tab) starts a chemical reaction that generates inert gas, building typically 0.5–3 bar behind the piston. Simple, power-free, and disposable — but gas pressure is temperature-sensitive: output drops significantly below 0°C and accelerates in heat, shortening the discharge period. Best for mild indoor environments where simplicity trumps precision.
Electrochemical
A battery powers an electrochemical gas cell, giving more controlled pressure generation (roughly 1–6 bar depending on model) than a pure chemical reaction, with selectable discharge periods. These units combine wire-free installation with reasonable rate control, though battery capacity suffers below −10°C.
Electromechanical
A battery-driven motor turns a spindle or small pump, delivering the most precise and repeatable dosing of the four types — independent of temperature and back-pressure. Advanced models add LED status indication, empty-cartridge alarms, and even machine-linked operation (lubricate only while the machine runs). Batteries typically last 1–5 years depending on the design. Example: our automatic single point lubricator with 1/3/6/12-month settings up to 5 bar.
Selection: Grease Volume, Discharge Period (1–12 Months), Temperature Range
Three questions size a single-point lubricator correctly:
- How much grease does the point need per day? Estimate relubrication quantity with the standard formula G (g) = 0.005 × D × B (outer diameter × width, mm) and the bearing maker’s interval, then convert to grams per day. Our bearing lubrication calculator does this with corrections for speed, temperature, and environment.
- What service interval do you want? Reservoir ÷ daily consumption = service days. A 60cc unit at ~1 g/day lasts about two months; a 250cc unit at the same rate approaches eight months. Choose the discharge-period setting (1, 3, 6, or 12 months on programmable units) that matches your inspection rounds.
- What is the ambient temperature? Below freezing, avoid pure gas-driven units; spring-driven (to −20°C) and electromechanical models are the cold-safe choices. Above +60°C, verify the unit’s rating — spring units rated to +100°C cover most hot-zone applications.
Also check outlet pressure against your installation: heavily spring-loaded seals or long small-bore remote lines may need more than the 3–4 bar of basic units — step up to a 5–6 bar model or shorten the tube run.
Applications: Motors, Pumps, Fans, Conveyor Bearings
Single-point lubricators earn their keep anywhere a grease point is continuous-duty, hard to reach, or easy to forget:
- Electric motor bearings: consistent micro-dosing avoids both starvation and the over-greasing that overheats windings-adjacent bearings — the single most common application.
- Pumps and fans: continuously running equipment in plants that operate 24/7 and cannot stop for greasing rounds.
- Conveyor idler and drive bearings: dozens of points spread along long runs; large 250–532cc reservoirs minimize inspection trips.
- Elevated or guarded points: overhead crane end trucks, rooftop HVAC bearings, points behind safety guards — anywhere manual access needs scaffolding, lockout, or fall protection.
- Outdoor and remote equipment: gates, water pumps, ventilation systems where weather makes fixed-schedule manual service unreliable.
When point counts grow beyond roughly half a dozen per machine, evaluate a centralized single-line or progressive system instead — see our single-line lubrication system hub for the next step up.
Comparison Table: Which Type Fits Your Application?
| Type | Output Pressure | Temperature Range | Refillable | Best For |
|---|---|---|---|---|
| Spring-driven | Up to ~4 bar (65 PSI) | −20°C to +100°C | Yes — reusable | No-power sites, cold climates, ATEX zones, simple reliability |
| Gas-driven | Typically 0.5–3 bar | Poor below 0°C | Usually disposable | Mild indoor environments, lowest complexity |
| Electrochemical | ~1–6 bar (model dependent) | Battery-limited below −10°C | Some models | Selectable discharge periods without wiring |
| Electromechanical | Up to ~5–6 bar | −20°C to +60°C (model dependent) | Some models | Precise dosing, status alarms, critical equipment |
Browse the full range on the single-point lubricators category page or the single point lubricator hub.
Frequently Asked Questions
What is a single point automatic lubricator?
A self-contained device that holds a small grease or oil reservoir (typically 60–250 cm³) and dispenses it automatically to one lubrication point over a set period of 1–12 months — replacing manual greasing for that point.
How does a single point lubricator work?
A drive mechanism — spring, generated gas, electrochemical cell, or battery motor — maintains pressure on a piston behind the lubricant, forcing a controlled flow through the outlet into the bearing. A flow adjuster or electronic setting determines how fast the reservoir empties.
How long does a single point lubricator last?
Service life equals reservoir size divided by the bearing’s daily grease consumption. Typical settings deliver 1, 3, 6, or 12 months of operation; a 250cc unit feeding a standard motor bearing commonly runs six months or longer.
Can single point lubricators be used outdoors or in cold climates?
Yes, with the right type. Spring-driven units operate from −20°C to +100°C and are unaffected by cold; electromechanical units typically rate to −20°C. Avoid pure gas-driven models below 0°C, because gas pressure — and therefore output — falls with temperature.
When should I choose a centralized system instead of single-point lubricators?
When one machine has roughly 6 or more lubrication points, when you need positive blockage alarms on critical bearings, or when refill labor on many individual units exceeds the cost of one pump and divider network. Single-line and progressive systems refill from a single reservoir and monitor every cycle electrically.
Tell us your bearing list, temperatures, and access constraints through our quote request page, and we will recommend the right lubricator type, capacity, and discharge setting for each point.
ISOHITECH supplies aftermarket-compatible lubrication components. Brand names are used for compatibility reference only. ISOHITECH is not an authorized OEM dealer.
