The comparison question usually arrives from a supervisor watching two things at once: a tray or fixture of parts coming off a machine still wet with cutting fluid, and a crew spending the end of every shift on rags and solvent. Steam is proposed as the alternative. Before anyone changes the method, the comparison has to be run against facts you can measure at your own workstation, not against brochures. This article sets out what to compare, in what order, so the decision is defensible later when the line schedule changes.
Start with the residue, not the machine
"Oil residue" on machined parts is not one soil. Separate it into three states before comparing anything.
The first state is a wet film: fluid that has not been allowed to dry. It can usually be displaced with heat and water, and the real work is removing the liquid rather than scrubbing it.
The second state is an emulsified, dried film, where water-based cutting fluid has dried and left the binder behind on the surface. This is the state where manual wiping most often fails, because the operator applies pressure and hopes the cloth lifts something that had already bonded to the part.
The third state is baked residue: fluid that has been driven hot, for example on a part that passed through a warm wash, a dryer, or a chip conveyor under a lamp. Treat this as the hard case, and take a sample deliberately. Photograph the worst fixture you own, from a fixed angle, and keep that photo as the reference for the whole trial.
A machine tool steam cleaning conversation with any supplier is only useful once you can send them this classification. If the soil state is not defined, every answer you receive is a guess.
What manual degreasing actually costs you
Most factories can state the price of a drum of solvent and a box of wipes. They cannot state the cost of the method. For the comparison, record the manual baseline as four numbers over one week, on the same workstation, using your own staff.
First, minutes per basket or fixture, timed from the moment the operator touches the first part until the last part is racked. Second, the number of parts that go back for a second pass, which is the honest measure of whether the method is repeatable. Third, how far the operator walks for solvent, rags, and disposal. Fourth, when during the shift the work can actually be done, because manual degreasing is often pushed to after the last cut rather than performed inside a cycle.
Write these down before you look at any equipment. A method change that cannot beat a number you never recorded will still look like a good idea on a Friday afternoon and will not survive an audit on Monday.
Where heat and water change the mechanism
The difference between the two methods is not effort; it is mechanism. Manual degreasing depends on a solvent wetting the film and a cloth carrying it away. Heat and water, applied as steam or as hot water, work on the film itself and on the surface temperature, so the operator controls the condition instead of the pressure of a hand.
Four variables decide the result, and they should be written down for any option you compare: the temperature of the surface being cleaned, how long the heat stays on it, the distance between the nozzle and the surface, and how fast the wand travels. If a supplier cannot tell you which of these their figures refer to, and where the temperature and pressure were measured (in the boiler, in the line, or at the nozzle tip), treat the specification as unanswered rather than as favourable.
This is also where the choice of mode matters. CNC machine cleaning equipment listings, including our Cleaning Equipment Series, describe dry steam, wet steam, and hot water as different modes, and they are not interchangeable on a shop floor: dry steam suits surfaces where you cannot afford extra water, hot water suits heavier films where you can manage the run-off. Ask the supplier to state, in words, what each mode is for on your surfaces.
What steam cannot do on a machining floor
Be blunt about the limits in the comparison document, because they are the part that causes a failed installation.
Residue that carries grinding and lapping fines is different from plain dried fluid. The danger is not the oil; it is that the abrasive particles get moved across a surface that has already been finished. Evaluate that stream before you commit to any wet method.
Second, water goes where it is pointed. On and around a machine that means enclosures, junction boxes, drives, sensors and encoders, cable chains, connectors, ways that carry a lubricant film, and vents. Before any trial, have the maintenance lead sign a list of components that must not be sprayed, together with the isolation and lock-out steps and the requirement that the machine is cold. This list is a condition of the comparison, not an afterthought.
Third, geometry decides throughput. Blind holes, tapped pockets, deep fixture channels and stacked trays need a defined draining path; parts that trap water will fail a downstream drying or coating step, and that failure will be blamed on the cleaning method.
Fourth, the utilities at that exact position decide whether the option is possible at all. Ask whether there is a protected 220 V outlet at the workstation and how the cable will run without crossing an aisle. Ask where water will be drawn from; our fixed HW02 page names the inlet requirement as a 1/2 inch four-point internal-tooth tap-water connection, and mentions hard water as a maintenance condition, so scaling belongs in the comparison as a maintenance duty, not as a surprise. Ask where the oily run-off goes and who owns collecting it or routing it through an oil separator. Ask whether the doorway, threshold and floor space allow the equipment in.
Run the comparison on your own floor
Do not accept a video of someone else's parts. Fix the conditions and repeat them three times.
Choose the worst fixture you own and a shift window you can genuinely control. Use your own operators, not a visitor. Set the mode, nozzle, distance, travel speed, number of passes and any detergent dilution, then record those same six settings for all three repetitions. Take a second photograph from the same fixed angle.
Write the pass criteria before the trial starts, in checks a person can perform and sign: no film on a white cloth wipe of a defined area, no lifting or discoloration of painted and coated surfaces, seals re-checked with no water ingress, and the floor or rack dry enough to walk on within the agreed interval. Name the person who signs, and name the checks that fail automatically.
Judge the result against your manual baseline, not against advertised claims. The comparison table should have one column per option and should leave unanswered cells empty; an assumed number is worse than a blank.
Keep the equipment itself in the comparison
A method that depends on a machine inherits that machine's condition. Protection functions named on the HW02 page, including leakage, short-circuit, high-temperature, high-voltage, water-shortage and high-voltage-explosion protection, describe electrical and water-supply conditions; a trip means stop, record, and have the cause inspected rather than resetting it repeatedly. The same page's figures describe installation conditions: 220 V working supply, 6 kW heating load, and an 80 L SUS304 tank. None of those figures is a claim that a particular surface can be cleaned here.
Put the inlet filter check, the descaling duty, and the nozzle inspection in the same document that fixes your cleaning parameters, with a named owner. Compare the reference model for its PowerDe HW02 steam cleaner page only against what your trial showed.
What to send when the answer is not a catalogue model
Send the surface list, the soil classification, the photographs, the timed manual record, the signed list of protected components, the utilities available at that position, and where the waste water goes. Our customized steam cleaning equipment service exists for that situation, and the PowerDe contact page is where the brief belongs. The same three facts also let our engineers test your own sample parts before you buy, which is the shortest way to close a comparison you cannot close on paper.
Whichever method wins, freeze it as a one-page controlled sheet: the mode, the six settings, the pass criteria, the PPE, the isolation steps, and a single line of record per batch. A comparison that ends in a method sheet will still be true in a year. A comparison that ends in a purchase order will not.
