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

1/4-20 Tap, Spiral Point Plug, UNC STI thread, H4/H5, 3 flutes, HSS-E, TiN Coated

  • Item Code: 3990-6.350
  • 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
Overall Length (mm) 69.1007
Number of flutes 3
Diameter (mm) 6.35
Brand Guhring
Reach (decimal) 1.3770
Square Size (decimal) 0.1909
H Limit H4/H5
Diameter 1/4-20
chamfer (decimal) Spiral Point Plug
Series 3990
Shank Diameter (mm) 8.0772
Coating TiN
Material HSS-E
Overall Length (decimal) 2.7205
threadtype UNC STI