SCHRODER TRIWING NO6X25MM CLASSIC BIT SC25150Classic Tri wing Bits Tri wing Bit: No. 6 (length: 25 mm) Packaging: Bulk (sold per piece) For applications where screws and bolts must be torque tight and tamper resistant. The tri wing, also known as triangular slotted, is a screw with three slotted 'wings' and a small triangular hole in the centre. The design was adopted by some parts of the aerospace industry, led by Lockheedthe early 1970s. In the present day it is usually seen on electronics