Guide · Haircare

Lotion pump dose (2 ml vs 4 ml) and the 1,500-cycle test:
what to specify.

A pump is the part of a bottle that customers touch a thousand times, and the part most often bought as an afterthought. The dose decides how the product feels and how long the bottle lasts; the cycle test decides whether the pump still works in month three. Both are numbers you can write into a purchase order.

By the Vella sourcing team · Updated September 2026 · 8-min read

Short answer

Lotion pumps come in output steps of 0.5/0.7, 1.0/2.0, 3.5 and 5.0 cc per stroke; a “2 ml” brief lands on the 1.0/2.0 cc step and a “4 ml” brief on the 3.5 cc step (or 5.0 cc on a 1,000 ml pack). 2.0 cc suits 200–400 ml body lotion and conditioner; 3.5 cc suits 500 ml+ shampoo and body wash. Whatever the dose, the pump must survive ≥1,500 continuous actuations, prime in ≤5 strokes on an aqueous bulk (≤10 non-aqueous), return in ≤3 s, recover ≥95% of the fill, and hold a 50-stroke average within 5–10% of the specified dose with single strokes at ±15% — measured with your actual formula, not water.

How a lotion pump is sized

A lotion pump has around eleven parts — actuator, upper stem, lock collar, gasket, closure, pump seal, lower stem, spring, housing, glass or steel ball and dip tube. Dose is fixed by pump diameter, stroke length and spring force. Because new tooling for eleven parts is expensive, stock (common-mould) pumps are the default unless a brand is committed to a proprietary shape, and stock pumps come in fixed output steps rather than any dose you name.

ParameterStandard options
Neck sizesΦ18, Φ20, Φ22, Φ24, Φ28, Φ33, Φ38 mm — matched to the bottle T dimension (24/410, 28/410 on haircare)
Output per stroke0.15/0.2 cc · 0.5/0.7 cc · 1.0/2.0 cc · 3.5 cc · 5.0 cc · 10 cc and above
Lock headGuide-block lock · screw lock · clip lock · no lock
StructureExternal-spring · plastic-spring · leak-resistant · high-viscosity pump
FeedDip tube (standard lotion bottle) or airless piston
Spring positionExternal spring never touches the formula; internal-spring pumps are cheaper but need a compatible spring alloy

Two consequences for the brief. First, ask for the step, not a round number: “1.0/2.0 cc” or “3.5 cc”, not “about 2 ml”. Second, the spring matters as much as the dose — an external-spring pump keeps a corroding spring out of a natural or acidic formula. Full pump data are on airless, pump and sprayer specifications.

2 ml or 4 ml: choosing the dose

The right dose is the amount a customer uses in one application, delivered in one or two strokes. Too small and the pump feels mean and gets pumped five times; too large and the product is wasted and the bottle empties early. Partner-factory practice on 200–1,000 ml haircare and bodycare packs:

Product and pack sizeTypical dose stepWhy
Body lotion, leave-in, 200–400 ml on 24/410 or 28/4101.0/2.0 cc (a “2 ml” pump)One application of lotion for arms or legs is two strokes; standard pumps average ≥3 g per stroke on aqueous bulk, so 2.0 cc keeps waste down
Conditioner or hair mask, 250–400 ml2.0 cc; disc-top or flip-top for the thickest masksViscosity 2,000–50,000 mPa·s — a standard 0.5 ml pump will not prime; test the orifice with the actual bulk
Shampoo, body wash, 500 ml on 28/4103.5 cc (what a “4 ml” brief lands on)One stroke per wash; wash-off products are dosed larger than leave-on
Family / salon body wash, 750–1,000 ml3.5 or 5.0 cc large pumpDry-pump strokes allowed rise from <8 to <10 above 1,000 ml
Styling gel, 250 ml1–2 ml wide-bore pumpGels string and cling; wide bore prevents suck-back
Hand soap / hand cream, 200–300 ml0.5/0.7 or 1.0 ccSmaller application; 0.7 cc is the common hand-wash step

If the same pump must serve shampoo and conditioner in a matching set, size it for the thicker bulk and accept a slightly generous shampoo dose. If you are undecided between 2.0 and 3.5 cc, sample both — a pump is priced in the same order of magnitude at either step, and the choice changes how many bottles a customer buys in a year.

The 1,500-cycle test and the rest of the sheet

These are the numbers a partner factory signs against for a lotion pump. They are run on samples filled with your actual bulk, because a cream that primes in 5 strokes with water can need 15 with oil.

TestPass threshold
Service life≥1,500 continuous actuations; no loss of dose, no sticking, no dead travel
Dry-pump (air) strokes<8 strokes for bottles ≤1,000 ml; <10 above 1,000 ml
Priming with product≤5 strokes aqueous; ≤10 strokes non-aqueous
Output per strokeSingle stroke ±15%; 50-stroke run average within 5–10% of the specified dose
Dose stabilityEven and stable; standard pumps average ≥3 g (ml) per stroke; 1–2 ml on 250 ml styling-gel pumps
Dispensing efficiency≥95% of an aqueous fill recovered; ≥90% non-aqueous
Return timeActuator returns in ≤3 s
Dip tubeLength measured to 0.02 mm; tolerance +2/−1 mm; 5 mm clearance from the base on a 250 ml bottle
Thread / fitClearance 0.1–0.8 mm; no thread strip at rated torque; fit-critical dimensions ≤0.5 mm
ThermalClosures −24°C / +50°C; filled pack 48°C and −15°C, 24–48 h each; the rubber seal hardens below 0°C, so the elastomer is specified against formula and route

How output is measured

Fill to nominal volume, prime with 15 strokes, weigh. Press 50 continuous strokes, weigh again. (Weight before − weight after) ÷ 50 = single-stroke dose. Repeat three times and average. The result is what the specification is signed against, and it is the number that should appear on the incoming-inspection report at the filler.

What fails in the field

The seal at the glass or steel ball under the spring is critical: if it leaks, product flows back into the bottle on each stroke, suction drops, and the pump starts “losing” doses after a month. A loose actuator-to-valve fit causes back-flow and resistance at the nozzle. Both are visible at IQC sampling — which is why the pump is sampled and weighed before it goes near a filling line, not after the first complaint.

MOQ and lead time for the pump itself

A stock 24/410 or 28/410 pump in black or white sits in the low thousands, matched to the bottle quantity, and runs 20–30 days from separate sub-assembly lines — in parallel with the bottle, so it rarely sets the date. A custom-colour actuator follows the spray minimum of 2,000–5,000 per set-up; a metallised or plated actuator moves to about 10,000 pieces and joins a plating queue. A proprietary pump is eleven tools and is only worth it once the line is proven. The per-component logic across formats is on the MOQ index 2026; the format on HDPE shampoo bottles and the range on haircare and bodycare packaging.

The pump line in your specification

One line, seven fields: “28/410 lotion pump, 3.5 cc, guide-block lock, external spring, dip tube cut to bottle (+2/−1 mm, 5 mm off base), black PP actuator; tested on actual bulk to ≥1,500 actuations, ≤5 priming strokes, ≥95% output, 50-stroke average within 5–10% of 3.5 cc.” Add the vacuum leak test (−0.06 MPa; −0.08 MPa 15 min ≤0.5% for volatile bulks) and 24 h inversion on the filled pack, per cosmetic packaging quality standards, and the neck drawing per neck finish and closure standards.

Vella is a Guangzhou-based beauty packaging solutions provider — a sourcing partner, not a factory — that routes briefs like this one to vetted partner factories operating to ISO 22716 / GMP, matches the components as one set, and runs the tests above on filled samples before any production run. If a supplier cannot tell you the output step and the priming stroke count on your bulk, use the checklist in how to evaluate a China packaging supplier before committing — or send the brief through the contact page.

Common questions

Should a shampoo pump dispense 2 ml or 4 ml?
Size to one application. A 200–400 ml body lotion or conditioner normally takes the 1.0/2.0 cc step (a 2 ml pump); a 500 ml shampoo or body wash takes the 3.5 cc step, which is what a 4 ml brief lands on; 750–1,000 ml family packs use 3.5 or 5.0 cc. Stock pumps come in fixed steps of 0.5/0.7, 1.0/2.0, 3.5 and 5.0 cc, so specify the step, not a round number.
What is the 1,500-cycle pump test?
The pump is actuated continuously on a sample filled with the actual formula for at least 1,500 strokes and must keep dosing evenly with no sticking or dead travel. Alongside it: priming within 5 strokes on an aqueous bulk (10 non-aqueous), actuator return within 3 seconds, at least 95% of the fill recovered, and single-stroke output within ±15% with the 50-stroke average within 5–10% of the specified dose.
How is lotion pump output measured?
Fill to nominal volume, prime with 15 strokes and weigh. Press 50 continuous strokes and weigh again. Weight before minus weight after, divided by 50, is the single-stroke dose. Repeat three times and average. The specification is signed against that figure, and it should appear on the incoming inspection report before filling.
Why does a pump that worked at sampling lose doses after a month?
Usually the seal at the glass or steel ball under the spring. If it leaks, product flows back into the bottle on every stroke, suction drops and the dose falls away. A loose actuator-to-valve fit causes the same back-flow and resistance at the nozzle. Both faults are visible at incoming-inspection sampling, which is why pumps are weighed before they go near a filling line.
Does the pump have its own MOQ and lead time?
Yes. A stock 24/410 or 28/410 pump in black or white is a low-thousands minimum matched to the bottle quantity, with a 20–30 day cycle that runs in parallel with the bottle. A custom-colour actuator follows the 2,000–5,000 spray minimum; a metallised or plated actuator is about 10,000 pieces. A proprietary pump means tooling around eleven parts and is only justified once a line is proven.
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