MIL-STD-681-SUP Identification Coding and Application of Hookup and Lead WireThis standard establishes identification coding systems for all insulated hookup and lead wire used in electrical and electronic equipment by the Departments of the Army, Navy, and Air Force. These coding systems should also be used for identifying lead wires on Hall generators and ac and dc wire coding methods specified see 4.9 and 4.10.

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MIL-STD-681F

TABLE V. Printing type size of identification marking. 1/

Insulation diameter 2/	Printing type
Insulation diameter 2/	Height of type face 3/ 4/ (± .001)	Radius of curvature of type face (± .001) 5/	Reading direction
For insulating materials that are not flattened during the printing the operation, following curved and flat face type shall be used:
.030 to .038 .039 to .048 .049 to .060 .061 to .090 .091 to .122 .123 to .154 .155 to .184 .185 to .248 .249 to .310 .311 to .374 .375 to .436 .437 to .498 .499 to .560 .561 to 1.000 Over 1.000	.015 .020 .025 .025/.031 .031/.046 .046 .062 .078 .093 .093/.125 .125 .125 .125 .125 .187	.020 .025 .031 .046 .062 .078 .093 .125 .156 .187 .218 .250 .281 Flat Flat	Vertical Vertical Vertical Horiz or vert Horiz or vert Horizontal Horizontal Horizontal Horizontal Horizontal Horizontal Horizontal Horizontal Horizontal Horizontal
For insulating tubings that are flattened during the printing operation, the following minimum flat face type shall be used:
.035 to .060 .052 to .068 .069 to .096 .097 to .166 .167 to .624 .625 to 1.000 Over 1.000	.065 .050 .062 .078 .109 .125 .187	Flat face Flat face Flat face Flat face Flat face Flat face Flat face	Vertical Horizontal Horizontal Horizontal Horizontal Horizontal Horizontal

1/ Dimensions are in inches.

2/ For heat shrinkable tubing, the height of the type face shall be governed by the "as supplied" insulation diameter.

3/ Other type face heights may be used only when approved by the contracting activity.

4/ For horizontal lettering, this quantity if the actual height. For vertical lettering, this quantity if the width of the letter. The letter height would be approximately 3 times this quantity.

5/ All industry standard sizes.

5.7 Striping or banding.

5.7.1 Colored helical stripes or circumferential bands. Colored helical stripes or circumferential bands shall be used only on all-white insulation wherever color combinations other than solid colored wires are necessary. Not more than three stripes or bands shall be used. Stripes and bands shall be applied in the same direction and shall conform to the color code designated in table I. Longitudinal (nonhelical) color striping may be used if colored insulation is used for striping.

5.7.2 Sequence. In the sequence of applying helical stripes or circumferential bands on a wire, the first stripe or

band shall be distinguishably wider than the second and third stripe or band within the group. Helical stripes shall run parallel to each other and shall be continuous, clearly defined, and constant in width and spacing throughout the length of the wire. Circumferential bands shall be parallel to each other around the circumference of the wire, shall

be clearly defined, shall be constant in width and spacing, and shall be continuous in repeated color groupings for the length of the wire unless specified (see 5.2.3).

5.7.2.1 Stripe or band width. The width of the stripe or band shall be measured perpendicular to the centerline of the stripe or band. The width of the wide (first) stripe or band shall be not less than 0.031 inch when the diameter over the marked surface exceeds 0.047 inch; when the diameter over the surface on which the stripe or band shall be not less than two-thirds the nominal diameter of the surface. The narrow (second and third) stripe or band shall be not less than one-half nor more than three-quarters the width of the wide (first) stripe or band. The third stripe or band shall be of the same width as the second stripe or band.