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    Indianapolis, IN 46203
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6-40 Tap, Modified Bottom, UNF STI thread, H3/H4, 3 flutes, HSS-E, TiN Coated, 40° Spiral Flute

  • Item Code: 3989-3.505
  • Brand: Guhring
  • Unit Size: 1

Description

An STI tap thread tap is designed to create an oversized thread to accommodate the required Heli-Coil insert. Screw Thread Inserts (STI) are helically formed diamond shaped stainless steel or phosphorous bronze wire that screw into a threaded hole to form a mating internal thread. Screw thread inserts are a convenient way of repairing stripped out threads and are also used to provide stronger threads in softer materials than can be obtained by directly tapping the base metal.

Tech Specs

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Diameter (mm) 3.503
Number of flutes 3
Overall Length (decimal) 2.1260
Overall Length (mm) 54.0004
Square Size (decimal) 0.11
Series 3989
Diameter 6-40
Brand Guhring
H Limit H3/H4
threadtype UNF STI
chamfer (decimal) Modified Bottom
Coating TiN
Helix Angle 40°
Material HSS-E
Reach (decimal) 0.9840
Shank Diameter (mm) 4.2672