PTFE Insulated Wires & Cables
WHAT IS TWS?
ADVANTAGES OF TWS
WIRES PER U.S.A. MIL-W-16878
SPECIAL EQUIPMENT WIRES
ADVANTAGES OF TWS
LIST OF MIL-W SPEC SHEETS
CONDUCTOR SIZE TABLE
INSULATED WIRE SIZES
COAXIAL CABLES PER MIL-C-17
TABLE OF COAXIAL CABLES
HIGH VOLTAGE WIRES & CABLES
HVCR SELECTION GUIDELINES
HVCR QUALITY ASSURANCE
HVCR SIZE TABLE
WIRES FOR FLOOR HEATING
products with PTFE outer covering are available in 10 standard
colours. MIL-STD-104 specifies the shade limits with light and
shades for each colour. The ten colours with their codes are:
The British specs, such as BS-2G-210, sometimes specify use of Pinkcolour also. Lighter shades of Blue andGreen offer 2 more choices (minimum order may apply) making a total of 14 solid colours.
For interconnections requiring larger number of colours, single-striped -- (bi-colours, i.e. solid colour with one distinct coloured stripe) and double-striped (tri-colours -- solid colour with 2 distinct coloured stripes) are also offered by us. In striped constructions, the common nomenclature to use the base colour as first followed by the stripe colour. For example, Yellow/Green refers to wire with yellow base and green coloured stripe.
These are generally as per MIL-681-B with some modifications of our own. For striped colours, caution is advised to see that the contrast between the base and stripe colours is good and they are distinctly visible against each other. For insulated diameter from 0.5 to 1 mm, one stripe is preferred because two stripes could be confusing. For diameters above 1 mm, 2 stripes are possible, but 3 stripes are not recommended.
It is sometimes noticed that the stripe on the wire can be scraped off with a sharp object. However, in our case, it is a special feature that the stripe cannot be removed. This helps in retaining the idenfication properties of colours. With regard to abrasion, the following clause of MIL-W-16878is relevant.
3.6.15Marking and Stripe Durability. A minimum of 125 cycles of the mandrel shall not remove the printed marking or color code stripe from the wire sample (see 4.5.16).
Another related issue is the retention of colour codes (including that of stripe) within the normal use conditions of the wire:
3.5.5 Colors. Colors shall be in accordance with MIL-STD-104, class I, except pastel colors shall be acceptable when crosslinking is done by irradiation. When insulation surfaces have been color coded with inks or dyes, they shall be nonconductive, permanently fast and shall not change, face, run, or bleed when used in direct sunlight and within the specific temperature rating of the insulation used.
Scheme 1. In one colour scheme followed by us, in case of some confusion, i.e., lack of colour contrast or sharp definition, the colour coding scheme will help in clearing the doubts. For example on a given body colour (which according to MIL standard can only be white and in some exceptional cases can be natural), the first stripe will be with the lowest colour code identification number, the second stripe can be only any one of the next higher code numbers. Thus, taking 9 as code for white body, it would be possible to have 918, but not 933 or 932. The advantage of this scheme is the availability of a larger number of colour combinantions in one and two stripes without the need of more expensive and clumsy three-stripe combinations (as will be necessary in MIL Standards). This scheme is as given below:
SINGLE STRIPES: Left digit is body colour and right digit is stripe colour.
MIL-STD-681-B Our Modifications
90 80 70
50 40 30 20
Similarly for the double stripes.
Scheme 2.After careful
of possible colour combinations, we have drawn up a list of good
and these are given below. These are based on experience and not
by any MIL Standards and the user must accept full responsibility.
of above recommendations, our customers sometimes specify various other
combinations and we try our best to give good colour contrast for each
bi- or tri-colour.
Teflon ® is a DuPont Trade Mark