Figure 2-38. Machine Screws
Figure 2-40. Self Tapping Screws
Drive screws. Drive screws, MS21318, as shown in figure 2-40, are plain head, self-tapping screws used
as capscrews in the attachment of nameplates in castings or in sealing drain holes in corrosion-proofing tubular
structures. These screws differ from other self-tapping screws in that they are not formed to fit screwdrivers and are not
intended to be removed after installation. Drive screws are installed by driving the screw into a drilled hole with a
Electrical Screws. Use round-head machine screws, AN508, as shown in figure 2-41, for electrical use in
such application as instrument installations where nonmagnetic qualities are desired.
Clamps. Clamp identification and types used in Army aircraft maintenance are presented in the
Clamp Identification. Clamps are identified as one of the following types.
Loop-type bonding clamp.
A plain metal uncushioned clamp, as shown in figure 2-42, which bonds
metal tube to the airframe.
Figure 2-39. Fillister Head Screw