The Heli-Coil STI tap is oversized from a standard tap to allow for the wire insert once installed. STI (Screw Thread Insert) taps are special taps that produce a larger than nominal hole to accommodate Heli-Coil wire inserts. High speed, steel intermediate (plug) lead taps cut threads to a precise dimension.
Brand: Heli Coil
Product Type: Tap
Tap Grouping: STI Tap
Tap Thread Size: 1/2 inch - 20
Number of Flutes: 4
itch Diameter Limit: H3
Tap Material: High Speed Steel
Tap Thread Type: UNF
Thread Length: 1 21/32 inch
Shank Diameter: 0.429 inch
Overall Length: 3 19/32 inch