
Spiral Pointed Tap Overall
length
L
Thread
length
ℓ
Thread+Neck
length
ℓn
Shank
dia.
Ds
Size of
square
K
Length of
square
ℓk
ZELX NI PO STI Spiral Pointed Taps for Nickel Base Alloys for Helical Coil Wire Screw Thread Inserts
L ℓ ℓn Ds K ℓk No. of
Spiral Pointed Taps Spiral Fluted Taps Spiral Fluted Taps
(for blind hole)
Size Class Code Chamfer Type
(inch) (inch) (inch) (inch) (inch) (inch) flutes
GH3 Y87262
STI 3/8-16UNC 4.5P 3.375 0.984 - 0.367 0.275 0.437 3 4
GH4 Y87270
GH2 Y87253
STI 3/8-24UNF 4.5P 3.156 0.866 - 0.323 0.242 0.406 3 4
(for through hole)
GH3 Y87263
STI 7/16-14UNC GH3 Y87264 4.5P 3.593 0.984 - 0.429 0.322 0.5 3 4
GH3 Y87265
STI 7/16-20UNF 4.5P 3.375 0.984 - 0.367 0.275 0.437 3 4
GH4 Y87275
STI 1/2-13UNC GH3 Y87266 4.5P 3.812 1.083 - 0.48 0.36 0.562 3 4
(for through hole)
STI 1/2-20UNF GH3 Y87267 4.5P 3.593 0.984 - 0.429 0.322 0.5 3 4
Hand Taps
Cemented
Carbide Taps Roll Taps
Pipe Taps Simple Inspection Tools
Thread Mills
Dies
Center Drills
Centering Tools
ANSI
PO-23
250