Goliath 2 1/4" x 8 UN HSS Tap Set - Goliath K826CD6

Features:

• 2 1/4" x 8 UN HSS Tap Set - Goliath
• HSS Bright Finish 8-UN Hand and Machine Tap Set.
• HSS Straight Flute Short Machine and Hand Taps.
• These general purpose taps are ideal for creating new threads in a wide variety of materials.
• Goliath HSS taps provide a high hardness to toughness ratio, compressive and tensile strength, good abrasion resistance and resistance to micro-chipping, ensuring a long tool life.
• In almost all thread series, the number of threads per inch decreases as the diameter increases.
• It became obvious to engineers using very large bolts on bridges and similar structures that this practice makes no sense for very large bolts.
• So for large bolts three series were defined in which all diameters have the same pitch; they are simply lists of standard diameters.
• All the bolts in the 8N series had 8 threads per inch, all in the 12N series had 12 threads per inch (used in boilers and for thin nuts on shafts), and in 16N, sixteen threads per inch (used where precise positioning of a big nut is required e.g., for bearing adjusting nuts).
• The N constant-pitch series were later replaced by the constant-pitch Unified Thread series, which have the Unified thread form and are designated 4-UN, 8-UN, and so on.
• Sometimes, for a particular diameter, the constant-pitch happens to be the same as the pitch in another Unified Thread series, in which case the fasteners are identical.
• Taper Taps have a lead of eight threads and are used as a starting tap in difficult or high precision holes.
• Intermediate Taps have a lead of four threads and are used in most general purpose applications to cut a thread true to a pre-drilled pilot hole.
• Bottoming Taps have a lead of two threads and are used to ensure minimum thread run-out when tapping to the bottom of a blind hole.
• Bottoming Taps are typically preceded by the use of a Taper or Intermediate Tap.
• Manufactured from HSS this general purpose tap is designed for use in medium tensile materials and is for hand or general machine use.