MIL-DTL-26126C
3. REQUIREMENTS
3.1 Specification sheets. The individual item requirements shall be as specified herein and in
accordance with the applicable specification sheet. In the event of any conflict between the requirements
of this specification and the specification sheet, the latter shall govern.
3.2 Commercial parts. Commercial parts having suitable properties may be used where, at the time of
award of contract, there are no suitable standard parts. In any case, commercial utility parts, such as
screws, studs, nuts, washers, etc, having suitable properties, may be used provided:
a. They can be replaced by the standard parts (MS or AN) without alteration.
b. The corresponding standard Part or Identifying Numbers (PIN's) are referenced in the
parts list and, if practical, on the contractor's drawings.
3.2.1 Standard parts. With the exception in 3.3.1, MS and AN standard parts shall be used where they
suit the purpose. They shall be identified on the drawing by their PIN's.
3.3 Materials.
3.3.1 Fungus-proof materials. Materials that are nutrients for fungi shall not be used where it is
practical to avoid them. Where used and not hermetically sealed, they shall be treated with a fungicidal
agent acceptable to the acquiring activity. However, if they will be used in a hermetically sealed enclosure,
fungicidal treatment is not necessary.
3.3.2 Metals. Metals shall be of the corrosion-resistant type or suitably treated to resist corrosion due
to fuels, salt spray, or atmospheric conditions as may be encountered in storage or normal service.
3.3.2.1 Dissimilar metals. Unless suitably protected against electrolytic corrosion, dissimilar metals
shall not be used in intimate contact with each other. Dissimilar metals are defined in MIL-STD-889.
3.4 Design and construction. Relays shall be of the design, construction, weight, and physical
dimensions specified (see 3.1). Relays shall be designed to ensure proper operation when mounted in
any position. Relays having adjustable features shall be designed so that the setting of any relay
adjustment will not be altered by the tests specified herein.
3.4.1 Threaded parts. All threaded parts shall be in accordance with FED-STD-H28. Where practical,
all threads shall be in conformity with the coarse-thread series. The fine-thread series may be used only
for applications that show a definite advantage through their use. Where a special diameter-pitch
combination is required, the thread shall be of American National Form and of any pitch between 16 and
36, which is used in the fine-thread series. Terminal threads shall be class 2A and 2B for external and
internal threads, respectively.
3.4.2 Circuit. The internal circuit and terminals of the relay shall be as specified (see 3.1).
3.4.3 Creepage and clearance distances. Unless otherwise specified, the minimum creepage
distance between current-carrying parts and ground shall be .125 inch (3.18 mm). The minimum spacing
between current-carrying parts of opposite polarity and any other portion of the relay, other than suitable
insulating material, shall be .0625 inch (1.588 mm).
3.4.4 Terminal finish. Finish of terminals shall provide a good electrical contact and meet the
performance requirements specified herein. Pure tin plating is prohibited internally and externally. Tin-
3
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business