WKT washers are hardware pieces for straight or cross-shaped
duct reinforcements in rectangular ducts and fittings. They
are always installed on both sides of the ductwork wall: one
piece is attached to the duct brace RURA tube and the other
piece is held on the outside surface of the duct with an SRS
bolt set in a plug.
The chamfered form keeps the washer pressed completely against
the duct sheet. This reduces the risk of tearing the duct walls under load.
