Sheet 07 · how a figure is taken
Reading a specification
Every figure on a listing was either copied off a carton or measured on the bench, and the listing says which. This sheet sets out the units, the order the figures come in, and the claims that are deliberately absent.
Units
Which unit belongs to which line
Units are fixed per kind of figure rather than per listing, so two lines in the same group can always be compared without converting anything.
- Millimetres
- Hardware: thread diameter, screw length, bracket thickness, hole centres.
- Centimetres
- Boxes, crates, textiles and anything whose footprint has to fit a shelf or a cupboard.
- Metres
- Rolls and continuous lengths, as printed on the carton.
- Millilitres and litres
- Liquids by millilitre. Container capacity in litres, nominal.
- Grams and kilograms
- Weight of a line as supplied. The parcel weight that a carrier rates is a different figure and is taken at the bench.
- Grams per square metre
- Fabric weight, where the mill states one. Absent where it does not.
- Pieces
- Pack quantity. Never expressed as a weight, because a weight cannot be counted at goods-in.
Order of figures
Length, then width, then height
Three dimensions are always given in that order, and always external unless the line says internal. External is taken across the widest point, which includes a moulded lip, a handle boss or a reinforcing rib: those are the parts that stop a tub sliding into a gap.
Where an internal figure matters more than an external one, as it does for a box bought to hold something specific, both are listed and each is labelled. A capacity in litres is never a substitute for an internal measurement: two tubs of the same nominal capacity can have quite different internal floors.
Tolerance
Nominal figures and where they move
Moulded and extruded goods vary between production runs. A stated dimension on this kind of line is nominal: the figure the tool was cut to, not a measurement of the piece in the box. Where a fit is tight, order one, measure it, and then order the quantity.
Capacity is nominal to the brim unless the line says it is measured to a fill line. A tub described by brim capacity carries less than its figure once a lid has to close on it, and that is a property of tubs rather than of this listing.
Colour is described in words. Dye lots and screen calibration both move, so a word is an honest description and a swatch on a screen is not.
Provenance
Carton print or bench measurement
A figure copied from the carton is recorded as printed, in the unit printed, even where that unit is awkward. A figure taken here is recorded as measured at the bench, with the method implied by the figure: external dimensions with a rule across the widest point, weight on the bench scale with the line out of its outer.
Where the carton and the bench disagree, both are listed and the disagreement is left visible. Resolving it quietly would mean publishing a figure that neither the maker nor the bench actually stands behind.
Absences
What a listing will not say
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No performance claim
Nothing is described as stronger, faster or longer lasting. Those are tests, and this desk runs no tests.
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No fitness for a purpose we cannot check
A line is not described as suitable for a use unless the carton itself carries that statement, in which case the listing quotes it.
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No food-contact or safety statement of our own
Where a carton carries a mark or a statement of that kind, the listing records that the carton carries it, and the carton in the box is the document that counts.
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No comparison with another line
Two listings side by side carry the same kinds of figures, which is a better comparison than a sentence of ours would be.