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Quarter Turn - PA-3500 Line
Manufactured in
the United States of America!
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Captive quarter-turn stud assemblies with multiple hole receptacle
rails.
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MIL-F-25173A* Approved
PA-3500 Line features captive, flare-in stud assemblies and continuous
receptacle strips with both stud and rivet holes on 3/8" (9.53 mm) centers.
The captive stud assemblies are offered in a range of neck lengths for
flare-installations into standard gage enclosure panels.
The receptacle strips are installed to frame out the console opening, serving
as offset supports for the stud panel. Continuous stud holes and installation
rivet holes are available every 3/8" (9.53 mm).
Quarter-turn fastening action offers operating convenience, predictable
clamping force, and locked vibration resistance. PA-3500 Line fasteners combine
those features with the versatility of continuous and closely-spaced panel
fastening points, and the ease of flare-in stud installation.
- Type 3506-SC stud assemblies consist of
a stud and coil spring captive in a steel cup. The assemblies are installed by
flaring the end of the cup neck into a countersunk panel hole. Stud locking
action compresses the spring, exerting a clamping force on the fastened parts.
In locking, the stud spiral cam engages a rigid wire which is offered by the
receptacle. MIL-F-25173A* approved.
- Type 3522-S stud assemblies provide a
nearly solid lock without allowing the sheet separation that occurs with 3506-SC
assemblies while under tensile overload sufficient to overcome the expansion
force of their springs. With 3522-S assemblies, the stud cam first quarter-turns
onto the receptacle wire under spring tension supplied by a curved washer.
Further locking rotation then starts to turn the cammed fastener head around a
stud cross-pin. The head is moved downward as it turns, compressing a coil
spring which is stronger than the curved washer, and finally compressing the
curved washer flat. At the fully-locked position, the assembly has no
remaining spring movement achievable by tensile overload. 3522-S assemblies are
not MIL-F-25173A approved.
CAUTION: Any external factor that prevents the stud from turning with
initial locking torque could allow the fastener head to rotate first. This
could convey an erroneous impression of locking while the stud cam has not
locked onto the receptacle wire. All operators of this special purpose
fastener should be trained to recognize proper stud cam locking.
- Standard receptacles The PA-3500 Line
receptacles come in both single hole and strip configurations. The strip
configuration acts as a supporting frame for the panels or removable parts to
be fastened, with continuous holes for stud engagement and rivet mounting on
3/8" centers. The strip is riveted to a support member and the stud panel
rests against the strip face having the stud holes. The strips are aluminum
alloy with a continuous rigid stainless steel wire staked across the underside
of the stud holes. The fastened panel rests on the strip and its captive
quarter-turn studs engage the rigid wire.
Custom cut lengths of 3590 and 3595 strips may be specially ordered. The
part callout system for cut lengths assumes standard hole spacing and location
of the holes at each end at the standard distance from the end.
* Meets the design, physical and performance requirements of
MIL-F-25173A. However, full mechanical properties testing may not be performed
on each production lot.
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