Reading a technical data sheet
A technical data sheet is read like a drawing.
Every figure has a quantity, a unit,
a condition and a status.
Without all four, it cannot be used to choose.
This page explains how we write our technical key data, and how to read those
in catalogues.
It does not replace the study.
It helps to prepare it.
A figure without its condition cannot be compared.
That is the rule behind this whole page.
One line, six pieces of information
On our pages, each technical key figure fits on one line.
It gives, in this
order, the quantity, the value, the unit, the condition, the variant and the status.
The quantity says what is measured.
The condition says what makes the value true, for
example without coupler, at the recommended flow or heaped.
The variant places the model
by machine class, never by a commercial reference.
A range is written with a dash, from the smallest to the largest.
The lines are grouped
in three blocks, in this order:
the carrier, the tool, the power source.
Mass, with or without coupler
A tool mass only makes sense with its condition.
Without coupler, without mounting plate,
without adapter, or with the tool fitted:
under the same word, catalogues do not weigh
the same thing.
The difference can be a whole mounting plate.
Two data sheets that show « Weight »
and say nothing more cannot therefore be compared.
On our pages, the line is called « Tool mass (kg) », always followed
by its condition.
And what counts at the end of the arm is the whole
assembly:
the tool, its mounting plate, the coupler, and what the tool carries when it works.
Capacity, struck or heaped
A bucket volume is measured in two ways.
Struck, it is the volume under the plane that
joins the cutting edge to the back of the bucket.
Heaped, the heap above it is added,
with a slope set by the standard.
For an excavator bucket, this heap is counted at 1:1, to ISO 7451.
For a
loader bucket, it is counted at 2:1, to ISO 7546.
The heap does not have the
same shape, so the same figure does not mean the same volume.
The word « capacity », on its own, does not say what it measures.
We write « ISO 7451 volume
(m³) » for an excavator bucket, « Volume (l) » for a grapple, and a max. load in
kilos, at a given distance, for a fork.
A loader bucket and an excavator bucket of the same « capacity » do not hold
the same thing.
On our pages, a bucket volume carries its standard.
When it is missing, the line becomes « to be confirmed ».
Kilogram, decanewton, kilonewton and newton-metre do not mix
The kilogram measures a mass.
The decanewton and the kilonewton measure a force,
that of a jaw closing, a blade cutting, a plate compacting.
The newton-metre measures a torque, that of an auger or a rotator.
Putting these quantities under one word, « Permissible load » for example, loses what
they measure.
A force in kilonewtons is not a load in kilos, and a torque
is neither.
On our pages, « Permissible load » is reserved for
tools that lift.
We keep the unit in which the value was published, and we name the quantity
beside it.
A conversion, when it is useful, is written on a separate line, marked as
converted.
Why impact energy is given in joules
A breaker or a driving hammer does not push.
It strikes.
What counts
is the energy of each blow, in joules, and the rate of blows, per minute.
The mass of the hammer does not give this energy.
A heavier hammer that is poorly supplied
strikes less hard than a lighter hammer that is well supplied.
A flow without its pressure says nothing
Flow, in litres per minute, says how much oil reaches the tool.
Pressure,
in bar, says how hard it pushes.
A hydraulic tool needs both, and
one does not replace the other.
Nor does a pressure say anything without its role.
Max. pressure permitted by the circuit,
optimum working pressure, setting pressure, return pressure, locking
pressure:
five values, five uses.
« Recommended » is not « max. ».
The recommended flow is the one at which the tool
works as intended.
The max. flow is a limit:
beyond it, the tool overheats
and wears.
Below the recommended flow, it loses its rate.
On our pages, every flow carries « recommended » or « max. », and every pressure
says which one it is.
The value that counts is that of your machine,
at the outlet of the auxiliary circuit, not at the pump.
Tonnage is the mass of the machine, never a capacity
When a data sheet announces a tool « for 5 to 8 t excavators », it refers to the operating
mass of the excavator carrying it.
It is neither what the tool lifts, nor what
it weighs, nor what it holds.
The vocabulary does not always help.
Some catalogues call « power » what
is a machine mass in tonnes.
On our pages, the line is called « Carrier
class », in tonnes of operating mass.
These ranges are approximate, and they overlap from one model to another.
They
place a machine; they do not validate a fitting.
Two excavators of the same mass
can have a different circuit, coupler and stability.
How we say what we know
A value without a note is an order of magnitude, taken from the models we track.
When we have a doubt, we write it down plainly, in so many words.
-
Without a note
The value is read from a public manufacturer data sheet, kept on file for the page.
It gives the order of magnitude of a common model. -
« to be checked with you »
The value comes from a dealer or a summary, or else the manufacturer does not say under what condition it applies.
It is a guide, and we check it with you. -
« to be checked in the manual »
The value depends on your machine.
It is read in its manual, and in the tool's manual. -
« we calculate it with you for your machine »
Some figures matter for the choice, but depend on your machine and your work.
We do not make them up.
We calculate them with you, before proposing a model.
The note « Manufacturer example, indicative values », at the bottom of a block, says the same
thing.
No value on a page is a commitment that the tool fits your machine.
What the study checks, and the page cannot promise
A page describes a tool.
It knows neither your machine, nor your coupler, nor
your site.
- The exact model of the machine Its mass, its hitch dimensions, its auxiliary circuit and its cab control.
- The available flow and pressure At the circuit outlet, at working engine speed.
- The interface The coupler system and size, or the pin dimensions, and the mounting plate that follows from them.
- The mass at the end of the arm The tool, its mounting plate and its load, in the actual working position, set against the stability of the machine.
- The use and the material At equal tonnage, hard rock and topsoil call for neither the same tool nor the same wear.
These are the values that commit us.
They are checked on
the exact model, and written in the answer sent to you.
The page helps to
ask the right question; the study answers it.
Is a value missing?
Tell us your machine and your work.
We establish the values that count
for your case, and we put them in writing.
Written study within 3 working days, complete file.