Warranty, Repair and Technical Support
Each PTX power wrapping and unwrapping tool, as well as the battery chargers, are covered with
a six-month warranty from date of purchase.
Repair service and technical support are available from OK Industries, Tuckahoe, NY 10707, phone:
914-793-0700, fax: 914-793-4527. Service and repair may be obtained from one of our many
worldwide facilities, and technical support can be provided by our representatives and distributors.
Please visit our web site at www.okindustries.com to contact a representative in your region.
Wire Wrapping Technology
Wire wrapping is a method of making a wire connection by coiling the bare wire around the sharp
corners of a terminal under mechanical tension. The technology was developed as an alternative to
soldering, which presents various safety and reliability problems in many applications. A principal
advantage of wire wrapping is that it provides a high-reliability connection that is also easily
removed to correct or modify a wiring layout.
Wire wrapping requires a rotating tool, called a bit. The bit has a large central hole in the face for
slipping the tool over the terminal, and it marks the point around which the bit rotates. The top of
the bit has a slot which accepts the wire to be wrapped. The front or face of the bit is shaped to
apply the proper tension to the wire during the wrap. This
contour also guides the wire into a helix that is tightly
spaced and uniform. During use, the bit is housed in a
metal tube called a sleeve. The sleeve retains the bit in the
collet of a wire-wrapping tool, which drives the bit as it
spins. It also keeps the wire in the slot during the wrapping
process and protects the worker from the rotating bit.
Wire wrapping subjects the wire to tremendous tension
and compression forces, typically 100,000 PSI at the
terminal’s edge. The wrapping action causes the oxide layer on both wire and terminal to be
crushed or sheared, resulting in a clean, oxide-free metal-to-metal contact. The number of turns is a
function of the length of uninsulated wire. Pre-stripped wire saves time and improves reliability, since
there is a specified minimum number of’ turns required for each particular wire size. These relate
directly to electrical conductivity and mechanical strength. However, if a manufacturing specification
requires a wrap with more turns, wire with correspondingly longer lengths of bare wire or further
hand stripping may be required.
There are two types of wire-wrapped connections: regular and modified. In a “regular” connection,
only bare (uninsulated) wire is wrapped around the terminal. A “modified” wrap, which requires a
modified bit, coils about 1.5 turns of insulated wire around the terminal in addition to the bare wire.
This method greatly improves a connection’s mechanical stability, such as resistance to vibration, in
cases where the wire diameter is small and its mechanical strength is low. The most important
element to consider when choosing either wrap method, then, is the size wire being used. A
standard wrap is generally used for 24 AWG and larger diameter wires; a modified wrap is
sometimes used for 26 AWG and smaller wires, and is used almost exclusively for 28 to 30 AWG
wires.
The four most common wire wrapping mistakes are (a) pressing too hard, which can lead to
overwrapping; (b) not pushing the stripped end of the wire all the way into the bit, which causes
insufficient turns; (c) removing the tool before completing the wrap, which can result in spiral and
open wraps; and (d) choosing the wrong bit and sleeve, which can cause problems ranging from
pigtails to loose wraps.
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