USCTI Table 303-A defines dimensional standards for special extension taps used in deep-hole threading. Learn specs, applications, and custom options from Taylor Tool.
Posts from September, 2026
USCTI Table 352 Basic Thread Dimensions Guide
Complete guide to USCTI Table 352 basic thread dimensions. Learn how to read the standard, apply tolerances, and select the right tap for your threading application.
Special Acme Taps: Custom Manufacturing & Specifications
Special Acme taps for trapezoidal threads. Taylor Tool manufactures custom Acme taps to your exact specification since 1918. Fast delivery across North America.
Special Trapezoidal Taps | Custom Thread Forms | Taylor Tool
Special trapezoidal taps manufactured to your exact specification by Taylor Tool. Custom Tr, ACME, and metric trapezoidal thread taps since 1918. Fast delivery.
Taper pipe tap thread limits and dimensions (USCTI Table 338)
Thread limits, projection tolerances, taper per foot limits, L1 lengths and tap drill sizes for NPT, ANPT and NPTF ground thread taper pipe taps from 1/16 to 4 inch.
Eccentricity tolerances of tap elements (USCTI Table 317)
USCTI Table 317 eccentricity tolerances for tap elements tested on dead centers. Covers square, shank, major diameter, pitch diameter, and chamfer for inch, pipe, and metric taps.
Optional neck and shortened thread tap dimensions (USCTI 302-A)
USCTI Table 302-A dimensions for ground thread taps with optional neck and shortened thread length, covering machine screw sizes #4 through 1 inch and metric M3 through M25.
UNJ thread profile: controlled root radius (ASME B1.15)
UNJ thread standard (ASME B1.15) for highly stressed aerospace applications. Controlled root radius 0.15011P to 0.18042P on external threads, increased minor diameter.
Tap nomenclature: definitions of tap and thread terms
Complete reference of tap and thread terminology including bottoming tap, plug tap, taper tap, chamfer, flute, pitch diameter, major diameter, and thread geometry.
Taylor Tool high speed steel material chart and specifications
High speed steel grades used in Taylor Tool cutting tools: HSS M2, HSCO M35, HSS-E M3, and M42 HSS-E with alloying elements, applications, and international equivalents.