U.S. Department of Defense MIL-PRF-46374G User Manual

INCH-POUND
MIL-PRF-46374G
12 November 1999
SUPERSEDING
MIL-W-46374F
14 October 1991

PERFORMANCE SPECIFICATION

WATCH, WRIST: GENERAL PURPOSE

This specification is approved for use by all Departments and Agencies of the Department
of Defense.

1. SCOPE

1.1 Scope. This specification covers analog wrist watches intended for general use, that are
intended to be continuously read, without any action required on the part of the wearer, for
periods in excess of 8 hours in low or no light situations.

1.2 Classification. The watches are of the following types, classes, and colors, as specified
(see 6.2).

1.2.1 Types. The types of wrist watches follow:

Type I - Analog, short life (2 years), non-maintainable, antimagnetic, water-resistant
Type II - Analog, long life (5-10 years), maintainable, antimagnetic, water-resistant, high

altitude, corrosion-resistant

Type III - Analog, long life (5-10 years), maintainable, antimagnetic, water-resistant, high

altitude, corrosion-resistant, with elapsed time ring

1.2.2 Classes. The classes of wrist watches follow:

Class 1 - Electrical movement, battery installed
Class 2 - Electrical movement, battery out of watch but packed with watch
Class 3 - Electrical movement, battery not included with watch
Class 4 - Mechanical movement, battery not required

Beneficial comments (recommendations, additions, deletions) and any pertinent data which
may be used in improving this document should be addressed to: Defense Supply Center
Richmond (DSCR), ATTN: DSCR-VBD, 8000 Jefferson Davis Highway, Richmond, VA
23297-5610 by using the Standardization Document Improvement Proposal (DD Form 1426)
appearing at the end of this document or by letter.

AMSC N/A FSC 6645
DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

MIL-PRF-46374G

1.2.3 Colors.

Color M - Silvery metallic
Color B - Black

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3 and 4 of this
specification. This section does not include documents cited in other sections of this specification
or recommended for additional information or as examples. While every effort has been made to
ensure the completeness of this list, document users are cautioned that they must meet all
specified requirements documents cited in sections 3 and 4 of this specification, whether or not
they are listed.

2.2 Government documents.

2.2.1 Standard. The following standard forms a part of this document to the extent specified
herein. Unless otherwise specified, the issues of these documents are those listed in the issue of
the Department of Defense Index of Specifications and Standards (DoDISS) and supplemented
thereto, cited in the solicitation (see 6.2).

STANDARD

DEPARTMENT OF DEFENSE

MIL-STD-810E - Environmental Test Methods and Engineering Guidelines

(Unless otherwise indicated, copies of the above standard are available from the
Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA
19111-5094.)

2.3 Order of precedence. In the event of a conflict between the text of this document and the
references cited herein, the text of this document takes precedence. Nothing in this document,
however, supersedes applicable laws and regulations unless a specific exemption has been
obtained.

3. REQUIREMENTS

3.1 Qualification. The watches furnished under this specification shall be products that are
authorized by the qualifying activity for listing on the applicable qualified products list (QPL)
before contract award (see 4.3 and 6.3).

3.2 Toxic chemicals, hazardous substances, and ozone depleting substances (ODS). The use of
toxic chemicals, hazardous substances, or ODS shall be avoided, whenever feasible.

2

MIL-PRF-46374G

3.2.1 Toxicity. The finished product covered by this specification shall have no adverse effect on
the health of personnel when used for its intended purpose.

3.3 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or
environmentally preferable materials should be used to the maximum extent possible provided that
the material meets or exceeds the operational and maintenance requirements, and promotes
economically advantageous life cycle costs.

3.4 Design. There shall be a stem set movement driving concentrically mounted hour, minute,
and second hands around a 12 hour dial. The dial background shall be black; the numbers and
graduations shall be white. Arabic numerals 1 through 12 shall be adjacent to and inside the hour
marks and arranged in a clockwise direction. Concentric with and adjacent to the numerals 1
through 12, in a smaller font, shall be the Arabic numerals 13 through 24. The 13 shall be
adjacent to the 1 o’clock; the 14 shall be adjacent to the 2 o’clock; and continuing until the 24 is
adjacent to the 12 o’clock. Manufacturer symbols or identification shall not appear on the dial.

3.4.1. Design approval. At the time of qualification testing, movement and case design shall be
reviewed by and subject to the approval of the government. Manufacturer drawings,
specifications, sample movements, sample cases, and supporting data, as applicable, shall be
submitted for government approval in accordance with 4.6.5.1.

3.4.2 Movement.

3.4.2.1 Class 4 (mechanical).

3.4.2.1.1 Mechanical power. The movement shall be powered by a stem wound and stem set
mainspring. When fully wound, the mainspring shall drive the complete movement a minimum of
36 hours without rewinding.

3.4.2.1.2 Jewel bearings, types II and III. The movement shall have 15 or more functional jewel
bearings located at bearing points most essential to reduce friction and wear of the train and
escapement parts.

3.4.2.2 Classes 1, 2 and 3 (electrical). Classes 1, 2 and 3 watches shall be powered by a self­contained electrical power cell. For type I classes 2 and 3, types II and III classes 1, 2 and 3
watches, the power cell shall be commercially available from a minimum of two manufacturers
and shall contain orientation marks which identify the positive (+) side. Internal contacts for the
power cell shall be made of, or plated with, material that shall not corrode. The electrically
powered watch shall operate a minimum of 2 1/2 years without the necessity to change the
battery.

3

MIL-PRF-46374G

3.4.3 Hand adjustment.

3.4.3.1 Hand setting. The minute hand shall not rotate (jump) at its tip, more than one tip width
when the crown is moved from the setting position to the “winding” position after setting the
hands.

3.4.3.2 Second hand stop mechanism. Pulling the stem, by means of the crown, to the setting
position shall result in stopping the movement. Rotation of the stem, by turning the crown, shall
permit the minute and hour hands to be advanced without any movement of the second hand.
Depressing the stem, by pushing the crown, shall result in complete operation of the movement
and hands. When the stem is pushed in, the watch shall start immediately.

3.4.4 Elapsed time ring, type III. There shall be an elapsed time ring concentric with the axis of
the watch. The elapsed time ring shall be designed to assure that the outer edge (shoulder) of the
crystal is recessed within the elapsed time ring. The background of the elapsed time ring shall be
the same shade of black as the background of the dial. The numbers and graduations shall be the
same shade of white as that on the dial. Around the ring there shall be 12 hour marks equally
spaced around the dial. Except for the number 12, all the marks shall be numerals starting with 1
and progressing clockwise to 11. The number 12 shall be replaced by a luminous mark. Between
the 12 o’clock and 1 o’clock, 1 o’clock and 2 o’clock, 2 o’clock and 3 o’clock, and the 3 o’clock
and 4 o’clock marks, there shall be four equally spaced minute marks. The periphery of the
elapsed time ring shall be made rough by checkering, knurling, serrating or any method that shall
facilitate the turning of the ring. The elapsed time ring shall move only when a torque of 180 ± 40
mNm (26 ± 6 inch-ounces) is applied both in the clockwise and counterclockwise directions. The
elapsed time ring shall be capable of withstanding, without damage, two forces, each of 44.5 ± 2
N (10 ± 1/2 pounds), applied to the lower side of the elapsed time ring with the 12 o’clock
luminous mark at the 3 o’clock position.

3.4.5 Case bars, types II and III. A watch strap shall be attached to the watch case at both ends
by means of integral bars or removable spring bars. A static pull of 67 ± 2 N (15 ± 1/2 pounds)
on the watch strap from each end of the case shall cause no damage.

3.4.6 Crystal strength. Crystals, that have been assembled to the case and that have been
subjected to the storage environment of table I, shall be visually inspected and tested for strength.
When visually inspected, the crystals shall be transparent, uncolored, and free from bubbles, striae,
scratches, chips or other imperfections that may interfere with reading the watch. When
functionally tested, the crystal shall show no visible damage of cracking or chipping.

3.4.7 Strap. The strap color shall be black.

4

MIL-PRF-46374G

TABLE I. Operating environment.

Environment Limits Duration
Simple harmonic vibration

Amplitude of 0.762 ± 0.127 mm
(1.524 ± 0.254 mm total excursion)

20 minutes with vibration
perpendicular to dial

Amplitude of 0.030 ± 0.005 inch
(0.060 ± 0.010 inches total excursion)

Frequencies varied uniformly between
30 Hz to 60 Hz to 30 Hz

Shock Drop from height of 50 cm (19.7

inches), uncontrolled, onto vinyl tile 3
mm (1/8 inch) thick affixed to
concrete block

Storage

Water resistance Complete immersion in distilled water

-45 °C ± 1.1 °C (-50 °F ± 2 °F)

15.5 °C to 32.2 °C (60 °F to 90 °F)
60 °C ± 1.1 °C (140 °F ± 2 °F) and

≥50 percent relative humidity

15.5 °C to 32.2 °C (60 °F to 90 °F)

with approximately 1 percent by
weight wetting solution under one
atmosphere (14.7 psi) and at room
temperature

20 minutes with vibration
in plane of dial and in
direction from 12 to 6

20 minutes with vibration
in plane of dial and in
direction from 9 to 3
Once

24 hours

24 hours

24 hours

24 hours
5 minutes

Complete immersion in distilled water
with approximately 1 percent by
weight wetting solution under three
atmospheres (44.1 psi) and at room
temperature

Water leakage Submerged in a measured volume of

distilled or deionized water, equal to
approximately 10 times the volume of
the watch, at 23 °C ± 1 °C
(73 °F ± 3 °F)

Magnetism, type I 14.5 to 15.5 Gauss magnetic field,

stem parallel to direction of field

Magnetism, types II and III

125 ± 1 Gauss magnetic field, stem
parallel to direction of field

5

5 minutes

24 hours

10 cycles of 3 seconds on

- 3 seconds off
10 minutes

MIL-PRF-46374G

TABLE I. Operating environment. - Continued

Environment Limits Duration
Altitude, types II and III Altitude of 10,700 meters

(35,000 feet)

Salt fog, types II and III Salt fog test Method 509.3,

MIL-STD-810
Human perspiration
resistance, types II and III

Immerse watch in a saturated sodium

chloride solution containing 5 percent

by volume lactic acid (65 strength) at

91 °C ± 1 °C (196 °F ± 2 °F)

60 minutes

48 hours

Instantaneous

Air dry

Store in atmosphere produced by a 50

percent solution of glacial acetic acid
Readability in total
darkness

3.4.8 Case markings. The back of the case shall be marked with the information shown in table II.

Item Descriptive title

Title and specification number WATCH, WRIST: GENERAL PURPOSE,

National stock number NSN
Amount of radioactive material MILLICURIES
Nuclear Regulatory Commission
manufacturer identification number
Contract number CONT NO.
Date DATE
Serial number SERIAL NO.
Manufacturer CAGE code MFR CAGE CODE

After having been stored in total

darkness for 8 hours, and without any

intervention on the part of the user,

watch shall be readable in total

darkness

TABLE II. Case markings.

MIL-PRF-46374G

NRC MFR ID NO.

2 hours

20 hours

8 hours

Note: The national stock number, contract number, and date may be applied without the
descriptive titles. The amount of radioactive material and the Nuclear Regulatory Commission
manufacturer identification number are necessary only if there is radioactive material present. The
marking of the month shall be the first three letters of the month and the marking of the year shall
be the year in full, e.g. April 2009 would be “APR 2009”. For type I class 3, types II and III class
3, and all class 4 watches, the date (month and year) shall be date of award of contract. For all
other watches, the date (month and year) shall be date of assembly. Only type I class 3 and all
class 4 watches shall be serialized. The serial numbers shall be assigned by the contractor. Serial

6

MIL-PRF-46374G

numbers of rejected watches shall not be repeated. For class 3 and 4 watches, the manufacturer’s
name and model or grade number shall be marked on the movement (barrel bridge, train bridge or
both).

3.4.9 Case.

3.4.9.1 Battery servicing. For type I classes 2 and 3 and types II and III classes 1, 2, and 3
watches, the power cell shall be replaceable without damaging the watch such that it would not be
able to meet all the performance characteristics of 3.5.

3.4.9.2 Finish and color. All visible exterior surfaces of the case assembly, excluding control
switches and spring type case bars, shall have a dull non-specular/non-reflective finish. The color
shall be silvery metallic or black as specified in the acquisition requirements (see 6.2).

3.5 Performance characteristics.

3.5.1 Vibration. While running, the watch shall not be damaged after being subjected to the
vibration environment of table I.

3.5.2 Shock. While running, the watch shall not be damaged after being subjected to the shock
environment of table I.

3.5.3 Storage. For class 1 watches, while running, the watch shall not be damaged after being
subjected to the storage environment of table I. For class 2 watches, both the watch and its
battery (battery not installed) shall be simultaneously subjected to the storage environment of
table I. For class 2 watches, at the conclusion of the storage test, the battery shall be installed in
the watch and the watch shall run without any evidence of damage. For class 3 watches, the
watch shall not be damaged after being subjected to the storage environment of table I. Class 4
watches shall not be run during test.

3.5.4 Water resistance. The watch shall show no evidence of leakage after being subjected to the
water resistance environment of table I.

3.5.5 Water leakage. While running, the watch shall not be damaged after being subjected to the
water leakage environment of table I. After the watches are removed from the water, if there is
any water in the crystal bowl at the completion of the test, it shall constitute a failure of the water
resistance test. (This test may be done concurrently with the radiological diffusion test in 3.6.3.)

3.5.6 Synchronization. The hour hand shall indicate the correct time within ±1 dial graduation
when the minute hand is at 12. To determine compliance, the setting mechanism shall be
activated and readings taken when the minute hand is at 12 and the hour hand is at the 3, 6, 9 and
12 hour positions respectively.

3.5.7 Magnetism. While running, the watch shall not be damaged after being subjected to the
magnetic environment of table I.

7