Tools & Gear Taps & Dies HSS Hand and Machine Taps

C220DA4 1" x 14 UNS Taper HSS Tap - Goliath HSS Bright Finish UNS Hand and Machine Taper Tap. 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. Unified National Special (UN) thread form was introduced in 1948 as an attempt to standardise thread forms in the USA, Canada and the UK. The thread profile of UNS is the same as for UN and metric threads and is described in the JIS B0206 standard. The thread is described by its major diameter and the number of threads per inch of length (TPI). UNS threads need to have the TPI specified; however the number of TPI for a specific diameter is limited. For example, within 12" diameter size, the TPI allowed are: 12" - 12 UNS, 12" - 14 UNS, 12" - 18 UNS, 12" - 24 UNS and 12" - 27 UNS. Taper Taps have a lead of eight threads and are used as a starting tap in difficult or high precision holes. Manufactured from HSS this general purpose tap is designed for use in medium tensile materials and is for hand or general machine use.