Goliath C821CD4 Tap Set, 1-1/8"

The Goliath UN HSS Bright Straight Flute Tap Set is an HSS bright finish tap set (taper, intermediate, bottoming). It is made from High Speed Steel (HSS). 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.

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.

Where this product is used

• Suits work in steel, aluminium, cast iron, stainless steel and plastics

Features

• HSS Bright Finish 8-UN Hand and Machine Tap Set
• HSS Straight Flute Short Machine and Hand Taps
• In almost all thread series, the number of threads per inch decreases as the diameter increases
• 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

Key specifications

Choosing the right option

The options differ in diameter, drill diameter, number of flutes and overall length. Each has its own part number.