MIL-PRF-26 Resistors, Fixed, Wire Wound \(Power Type\) General Specification ForThis specification covers the general requirements for power type, wirewound, fixed resistors for use in electrical, communications, and associated equipment. Included are general purpose styles of 5 percent initial resistance tolerance, with power ratings ranging from 3 watts to 240 watts at 25 Degrees C, derated to 0 power at 350 Degrees C \(characteristics N and V\) and precision axial lead types of .1\(B\) percent, .5 \(D\)percent, and 1 \(F\) percent initial resistance tolerances with power ratings ranging from 1 watt to 10 watts at 25 Degrees C, derated to 0 power at 250 degrees C \(characteristic U\).

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MIL-PRF-26H

3.21 Marking. Resistors shall be marked as specified in 3.21.1 to 3.21.4, inclusive. Marking shall remain legible at

the end of all tests.

3.21.1 All resistors except ferrule and edgewise-wound styles. The type designation and the manufacturer's name

or trademark, or both, shall be marked on the body of the resistor, parallel to the longitudinal axis. There shall be no

space between the symbols that comprise the PIN (see 3.1). If lack of space requires it, the PIN may appear on two

lines. In this event, the PIN shall be divided between the style, and the characteristic designation, as shown in the

following example:

RW20

V100

For the RW70 and RW80 series, the PIN shall be as follows:

RW70U

1002F

For resistor style RW81, the following reduced marking is optional:

ABCD - manufacturer's name or trademark

W81F - abbreviated PIN and resistance tolerance

1000 - resistance designation

In any case, full marking shall be included on the resistor package.

For resistors having a body more than 2 inches long, the resistance value in ohms preceded by the abbreviation for

"Resistance", and the power rating value in watts, followed by the abbreviation for the word "Nominal", shall also be

marked as shown in the following example:

RW33V162

Res 1600

26 W Nom

Manufacturer's name or trademark, or both.

3.21.2 Edgewise-wound or heavy round wire styles of 642 circular mils or over. These resistors shall be marked

with the PIN, manufacturer's name or trademark, or both, the resistance value in ohms, preceded by the abbreviation

for "Resistance" and power rating in watts, followed by the abbreviation for the word "Nominal", on the periphery of

the portion of the resistor body ends, not covered by wire. The PIN and the manufacturer's name or trademark, or

both, shall be marked on one end and the remaining information shall be marked on the other end as shown in the

following example:

RW29V161

Res 160

Manufacturer's name

11W Nom

or trademark, or both

All markings shall be approximately centered on a common longitudinal axis. If lack of space requires it, only the PIN

may be marked, divided as shown in 3.21.1.