Ask for discharge volume, not the model number
The number in a model name is not the number that reaches the formwork. Take the machine we document most completely, the SLM-18. The plant's own designation for it carries 3,200; its drum has a recorded geometric volume of 2,900 litres; and one batch discharges 1.6 to 1.8 cubic metres of mixed concrete. Three figures, all correct, describing one machine. The first is a nominal drum number, the second is the drum's own capacity, and only the third is what you pour. Across the sixteen self-loading mixers in our range record, fourteen carry a real discharge figure, running from 1.0 to 4.5 cubic metres, and four carry a geometric drum volume — but the two sets overlap on only two machines, so on fourteen of the sixteen even we cannot set the two side by side. Ask for cubic metres discharged, and ask which of the three the seller has just quoted.
Source: our range record — the SLM-18 at 2,900 L drum volume and 1.6–1.8 m³ discharged, both as declared by the plant; a real discharge figure on fourteen of our sixteen mixers, a drum volume on four.
Ask which posture the dimensions were measured in
Ten of the sixteen mixers in our record carry an overall length, width and height. Exactly one of the ten comes from a dimensioned drawing that separates the postures: the SLM-18 stands 2.58 m on its tyres and 3.45 m with the loading bucket at full lift. The other nine are single overall-dimension entries in plant documents that do not state whether the machine was measured standing or working, and our record carries that as an open question. Height is the dimension that moves. On the one machine where both figures exist the difference is 0.87 m, so an unlabelled height cannot be planned against a gate or a booking, and a quotation built on one is a guess with a decimal point in it. Width barely moves with posture and stays usable. This is among the cheapest questions to get answered, because the drawing already exists at the plant and nobody has to measure anything to send it.
Across the ten, width runs from 1.60 m to 2.30 m and length from 4.35 m to 7.06 m; recorded heights run from 2.45 m to 2.90 m, nine of them with no posture stated. That spread decides the job. These machines earn their keep where a ready-mix truck cannot go — an old city district with a gate and a turn, a village self-build with no batching plant in reach, a road where the pour front moves all day — and the narrow end of the range is a different machine from the wide end. A supplier who answers "about two metres" has told you nothing. Ask for the figure for the model on the proforma, ask which posture it was taken in, and measure the gate before the machine is built. The same arithmetic run against a container door rather than a site gate is set out in the container-fit guide on this site.
Source: our range record — overall dimensions on ten of our sixteen mixers, the ranges being the smallest and largest of those ten; nine of the ten come from plant documents that state no posture; the SLM-18 drawing gives 2.58 m standing and 3.45 m with the bucket raised.
Ask for the engine brand and the model number in one sentence
Ask for both together, because our record shows how easily they come apart. Seven of our sixteen mixers carry an engine brand. Nine carry an engine model designation. The two sets overlap on exactly one machine, the SLM-18, whose sheet reads Yuchai YCD4T22T-105 at 78 kW. On the other eight the model is a bare designation with no maker attached — mostly a series number such as 4102 turbocharged or 490 series. A series is not a part number. It will not identify a filter, a dealer or a parts list, which is what a buyer needs it for in the third year rather than the first, and it is the difference between a machine that can be kept running locally and one that cannot. Ask for the rated power in kilowatts in the same sentence; our record carries one on seven of the sixteen. Ask for a photograph of the engine plate while you are at it; it settles in one image what a specification table argues about.
Then ask for both language versions of the spec sheet and read them against each other. Our record holds a case where the English sheet prints one engine designation across seven machines with no power suffix, while the Chinese prints two longer ones, rated at 85 and 91 kW, on four of them. We cannot tell whether that is one engine spelled two ways or a dropped character, so we publish no engine model for those four. The same pair of documents disagrees elsewhere: on one machine, 126 horsepower against 125 while both versions agree the rating is 91 kW, so the horsepower figure for that machine goes unpublished and the agreed kilowatt rating is the one we carry; and front-wheel against articulated steering on that same machine. Neither is a translation slip to wave through. Each is two claims about one machine, and the version that reaches your proforma will be whichever one the salesman had open.
Source: our range record — an engine brand on seven of our sixteen mixers and an engine model on nine, overlapping on the SLM-18 alone, published as Yuchai YCD4T22T-105 at 78 kW; a rated power on seven of the sixteen; the recorded disagreements between the English and Chinese versions of one plant spec sheet. All figures declared by the plant, not measured by us.
Ask for the operating weight in writing, and ask what it includes
Three of our sixteen mixers carry an operating weight we are willing to publish. On two more we publish nothing: on one, the two language versions of the same plant sheet give different weights; on the other, the English figure repeats that machine's maximum payload exactly, which reads like a shifted row rather than a measurement. That leaves a figure that decides two practical things unconfirmed on most of the range. A container is capped at 26.5 tonnes of payload on a 40 ft box and 28 tonnes on a 20 ft, and that cap is what a second machine in the same box is weighed against. The yard at the far end plans its lift against a number somebody has to stand behind. Ask for the operating weight in writing for the model on the proforma, ask whether it is quoted wet or dry, and expect it on the packing list rather than in an email.
Source: our range record — an operating weight on three of our sixteen mixers, with two further machines withheld, one because the two language versions of one plant sheet disagree and one because the English figure repeats that machine's maximum payload; container payload limits from the catalogue's container table, 26.5 t on a 40 ft box and 28 t on a 20 ft.
Ask whether the weighing system is fitted, or merely available
Every one of our sixteen mixers carries a configuration list, and one of those lists is itself unfinished, with five items still owed by the plant. They are worth reading slowly, because they describe what the machine does on site rather than what it weighs. Seven of the sixteen describe a machine that draws its own water through a fill controller and a suction pump, slews a drum that lifts and rotates through 270°, and carries a reversing and drum-monitoring camera. Eight of the other nine name a large water tank filled from outside and none of those four items; the ninth is the unfinished list. Two lists that read alike therefore describe two different machines. What that cycle is worth against the crew and the plant hire you use today is arithmetic about your own site, and it needs your numbers, not ours.
What is missing from a list is the part to ask about. Electronic hydraulic weighing appears on the fitted list of exactly one of the sixteen, and automatic lubrication on that same one. On the other fifteen both are absent, and absent means the record does not say, not that the machine cannot have it. So ask for two separate written lists, fitted and optional, for the model and the build you are actually buying rather than for the range. Ask the same of the water system, for the reason above. The drum deserves the same question: a thickened base and individually replaceable mixing blades appear on eight of the sixteen lists and not on the other eight, and those are the wear items you meet again in year three. None of it is settled by a brochure photograph, and none of it survives being agreed verbally.
Source: our range record — a configuration list on all sixteen mixers, one of them recorded as incomplete; the water-controller, 270° drum and camera group on seven lists; an outside-filled water tank on eight; electronic hydraulic weighing and automatic lubrication on one; a thickened drum base and replaceable mixing blades on eight. All are the plants' declared entries, not our measurements.
Ask what the seller will not answer, and write that down too
Six mixer models are listed on this site and one of them has a detail page, because of a gate we wrote against ourselves. Six specifications must be on file before a model page goes live: what a batch discharges, the drum's geometric volume, the engine brand and model, the rated power, the overall length, width and height, and the operating weight. One model clears all six. The other five are short by three or four, and the shape of the shortfall is consistent — across our sixteen mixers an operating weight is on file for three and a rated power for seven. A page carrying four of the six is not a page with a few gaps; it is a page a professional buyer reads as evasive, which is why it does not exist yet. The standard behind that decision is set out on the how-we-work page.
Turn the gate around and it becomes the most useful question here. Ask a supplier which specifications he cannot confirm for the model on the proforma, and file that answer beside the ones he can. An instant answer to everything means a brochure is being read aloud or a figure improvised; the answer worth having is that he will ask the plant and send it in writing, followed by a document carrying the plant's own numbers. Four items on this list we cannot answer in full for our own range — the posture behind nine of our ten dimension sets, a complete engine identity on fifteen of our sixteen mixers, an operating weight on thirteen of them and a rated power on nine — and saying which four is the point of the list. The models we list, and the state of the specification behind each, are set out on the self-loading mixer range page.
Source: our range record and this site's own publishing gate — six specifications required before a model page goes live, one of the six listed mixer models clearing all six and the other five short by three or four; an operating weight on three of our sixteen mixers, a rated power on seven, an engine brand and model together on one, and a stated measuring posture on one of our ten dimension sets.