The short answer
Cost per part is total annual cleaning spend divided by parts cleaned — not the price per litre of concentrate. Include concentrate, drag-out losses, heating energy, water, effluent charges, labour, bath changes and the cost of rejects. Concentrate is usually a minority of the total, so a cheaper drum often raises cost per part.
- Concentrate share of total
- Typically the minority
- Working strength
- 1–5% (1:100 to 5:100)
- Wash temperature
- 55–65 °C (TCE needs 90–100 °C)
- Biggest hidden cost
- Drag-out and bath changes
- Trial packing
- 20 L pail
Ask what a cleaning chemical costs and you will be quoted a price per litre. It is the wrong number, and comparing two suppliers on it reliably picks the more expensive option. The figure that decides whether a wash line is well run is cost per part — total annual cleaning spend divided by the number of parts that came out acceptable.
This matters because concentrate is usually the minority of the total. A cleaner that costs 20% more per litre but works at half the concentration, lasts twice as long in the bath and cuts rejects is dramatically cheaper per part. Purchasing sees only the first number; the plant pays all the others.
The eight costs of cleaning a part
| Cost | Driven by | Usually controlled by |
|---|---|---|
| Concentrate | Working strength × bath volume × changes per year | Titration, correct dilution |
| Drag-out | Part geometry, basket design, drain time | 10–15 s drain, blind holes down |
| Heating energy | Bath temperature × hours at temperature × insulation | Lids, setback overnight |
| Water | Rinse design, bath changes | Counter-flow rinsing |
| Effluent | Volume dumped, treatment or haulage charge | Longer bath life |
| Labour | Bath changes, top-ups, testing, re-washing | A weekly log, not firefighting |
| Equipment wear | Pump cavitation, scaled heaters, filter spend | Foam and hardness control |
| Rejects and rework | Parts failing inspection, returned batches | Right chemistry for the metal |
Do the arithmetic once
The calculation is not complicated, and doing it once usually changes the decision. Take a single wash line over a year.
- 1Concentrate: bath volume × working strength × number of bath changes a year, plus top-ups. A 500 litre tank at 3% is 15 litres per fill — the fill is rarely the biggest line.
- 2Drag-out: estimate the film carried out per basket and multiply by baskets per year. On a high-throughput line this frequently exceeds the concentrate used in fills.
- 3Energy: hours at temperature × heater load × tariff. Running at 55–65 °C instead of the 90–100 °C a TCE vapour zone needs is a large and permanent saving.
- 4Water and effluent: litres dumped per change × changes, at your treatment or haulage rate.
- 5Labour: hours spent changing, dosing, testing and re-washing × loaded labour rate. Re-washing is the one people forget.
- 6Rejects: parts scrapped or reworked for cleanliness or corrosion × their value at that operation — not their material cost.
- 7Divide the total by parts cleaned. That is your real number.
Where the money usually is
Across the lines we look at, the same three items dominate, and none of them is the price of the chemical.
First, bath life. A soak tank with no skimmer might be dumped fortnightly; the same tank with a surface skimmer and a bag filter often runs a month or more. Doubling bath life halves concentrate spend, water, effluent volume and changeover downtime simultaneously.
Second, drag-out. Every basket leaves the tank wearing a film, and blind holes and box sections carry a great deal. Ten to fifteen seconds of drain time above the tank costs cycle time and returns a large fraction of that film — and it is charged three times over, as concentrate lost, rinse contaminated and effluent loaded.
Third, concentration control. Without titration, baths get dosed by eye. Under-dosing leaves residue and triggers longer cycles that burn energy without fixing anything; over-dosing wastes concentrate, increases drag-out and can start etching non-ferrous parts.
Why we quote a trial, not a price list
A price per litre is meaningless without the working strength, and the working strength depends on your soil, your metal and your equipment. The same product might run at 1% on a light maintenance soil and 5% on buffing compound — a fivefold difference in consumption from one number nobody asks about.
That is why the process here starts with a sample part and a description of your line, and ends with a supervised trial from a 20 litre pail. You get a dilution that has been proved on your own components, and a consumption figure you can actually budget against.
Send us your bath volume, throughput, current change interval and what you pay per drum. We will work out your cost per part as it stands today — before anything is quoted.
Get a cost-per-part reviewFrequently asked questions
How much does an industrial degreaser cost in India?
Per-litre price is not comparable between products because working strength differs — the same drum might run at 1% or 5% depending on soil and metal. Ask instead for the dilution proved on your part, which converts directly into litres per year and a cost per part.
Why is the cheapest cleaning chemical usually more expensive?
Because concentrate is normally the minority of cleaning cost. A cheaper product used at a higher concentration, with a shorter bath life and more rejects, raises spend on effluent, energy, labour and scrap by more than it saves on the drum.
What is the single biggest cleaning cost most plants miss?
Rejects. A part scrapped after machining has absorbed material, machine time and labour, not just material cost. Cutting a cleanliness or corrosion rejection rate by a few percentage points usually outweighs every other line in the calculation.
How do I reduce cleaning chemical consumption?
Attack drag-out and bath life first. Add 10–15 seconds of drain time above the tank with blind holes facing down, fit a surface skimmer and a bag filter, and hold concentration by weekly titration instead of dosing by eye.
Does a lower wash temperature really save money?
Yes, and permanently. An aqueous bath at 55–65 °C runs far below the 90–100 °C a trichloroethylene vapour zone needs, and heating is a continuous load for every hour the line is up.
