©
COPYRIGHT 2000 THE ESAB GROUP, INC. LESSON
IX 9.2.3
Operating
Factor - Operating factor is the percentage of a welder’s
working day that is actually
spent welding. It is the arc time in hours divided by the total hours worked.
A 45% (.45) operating factor means
that only 45% of the welder’s day is actually spent welding.
The balance of time is spent installing a new electrode
or wire, cleaning slag, positioning the weldment,
cleaning spatter from the welding gun, etc. 9.2.3.1
When using coated electrodes, (SMAW) the operating factor
can range from 15%-40% depending upon material
handling, fixturing and operator dexterity. If the actual operating
factor is not known, an average of 30% may be used for cost estimates when weld-
ing with the shielded metal arc welding process.
9.2.3.2 When welding
with solid wires (GMAW) or metal cored welding (MCAW) using the
semi-automatic method, operating factors ranging from
45%-55% are easily attainable. Use 50%
for cost estimating purposes. 9.2.3.3
For welds produced by flux cored arc welding (FCAW) semi-automatic-
ally, the operating factor usually lies
between 40%-50%. For cost estimating purposes, use a 45% operating
factor. The estimated operating factor for FCAW is about 5% lower than that
of GMAW to allow for slag removal time.
9.2.3.4 In semi-automatic
submerged arc welding, slag removal and loose flux handling must
be considered. A 40% operating factor is typical for this process.
9.2.3.5 Automatic
welding using the GMAW, FCAW, and SAW processes, requires that each
application be studied individually. Operating factors ranging from 50%
to values ap- proaching 100% may be obtained
depending on the degree of automation. 9.2.3.6
The chart in Figure 2 shows average operating factor
values for the various welding processes
that may be used for cost estimating when the actual operating factor is not known.
FIGURE 2 WELDING
PROCESS SMAW
*
GMAW *FCAW
*SAW 30%
50% 45%
40% *Semi-Automatic
Only + Metal Cored
Wires are Included APPROXIMATE
OPERATING FACTOR +
