• 5318 Victory Drive
    Indianapolis, IN 46203
  • (800) 622-4824
  • www.haggard-stocking.com

1/4-20 Tap, Modified Bottom, UNC STI thread, H4/H5, 3 flutes, HSS-E, TiN Coated, 40° Spiral Flute

  • Item Code: 3988-6.350
  • 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

Back To Top
H Limit H4/H5
Coating TiN
Material HSS-E
Overall Length (decimal) 2.7205
Reach (decimal) 1.3770
Square Size (decimal) 0.1909
Brand Guhring
threadtype UNC STI
Number of flutes 3
Shank Diameter (mm) 8.0772
Overall Length (mm) 69.1007
chamfer (decimal) Modified Bottom
Diameter 1/4-20
Helix Angle 40°
Series 3988
Diameter (mm) 6.35