AWC eUpdate Newsletter May 2007
UL Numbers: They May Be More Similar To Each Other Than You Think
If you read through Allied Wire & Cable's catalog, you may notice that for certain styles of wire more
than one UL number is listed. Multiple UL numbers for the same type of wire is typical for several common
wires across the cable industry. In many of these instances, the UL style will suddenly change when the
gauge size of the wire increases.
For example, if you look at the product specifications (as shown in the chart below) for lead wire UL 3173,
you will see UL 3173 is only attached to gauge sizes 22 AWG through 10 AWG. When the gauge size of the
lead wire increases to 8 AWG, the UL listing switches from UL 3173 to UL 3195. When the gauge size
increases even further to 6 AWG, the UL style changes from UL 3195 to UL 3196.
Why does the change happen? Look closely at the insulation thickness column above. When the UL number
changes, it is due to an insulation thickness change. For UL 3173 in a 10 AWG, the wall thickness is .030.
When the wire goes to an 8 AWG, the wall thickness changes to .045, so the Underwriters Laboratories change
the UL number.
Why are the UL Styles designated like this? There is no clear cut answer. According to the Underwriters
Laboratories, the differences can be traced back to when the entire system of UL numbering was created.
When the UL system was first put into place, certain customers requested certain thicknesses and AWG sizes.
UL marks were created accordingly for them. At that point, the UL numbers in a wire family were all
uniform.
As time went on, new styles were created for one of two reasons according to the Underwriters Laboratories.
First reason: New UL styles were created due to customers requesting different styles for marketing purposes.
Second reason: New styles were created because prior to having an electronic database, it was difficult to
find the UL styles that already existed. Since the styles already in place could not be easily retrieved,
the UL found it difficult to determine whether the style could be revised. Thus, they created new UL
numbers for very similar wires.
So next time you wonder why a certain UL style is not available in an 8 AWG, remember that different UL
styles for the same type of wire most likely are not all that different.
All UL styles are designated by the Underwriters Laboratories for product compliance. For more information
on the UL visit www.ul.com.
AWC's Value-Added Services to Appear in Upcoming Wiring Harness News
Get ready to have all your questions about value-added services answered in this month's Wiring Harness News.
Allied Wire and Cable has a feature article in the upcoming May/June issue of the publication. The article
examines various value-added services and the processes that each entails. Allied staff offers a glimpse
of the striping, dyeing, ink jet printing, hot stamping, braiding, twisting and cut and strip processes,
as well as information on special reel sizes and special packaging.
Be sure to pick up a copy of the May/June issue of Wiring Harness News and look for our value-added
services article. Wire Harness News is a bi-monthly newspaper serving the wire, cable and fiber-optic
processor. For information on subscriptions, visit
www.wiringharnessnews.com
or call 815-678-4000.