RS PRO 1/4 UNC Thread Tap Set, Straight Flute, HSS, Hand Tap, 2 Pieces, 66mm, UNC Standard 152-439

The RS PRO 152-439 Tap Set is engineered for reliable hand tapping of 1/4 UNC threads in a range of ferrous and non-ferrous materials. Designed with straight flute geometry, these taps provide efficient chip removal and maintain thread integrity during operation. Manufactured from premium high speed steel (HSS), the set ensures extended tool life, consistent performance, and resistance to wear.

This set contains two pieces: a taper tap with a 4° chamfer for starting the thread smoothly and a plug tap with a 23° chamfer for finishing. The progressive combination enables both initial entry and full-depth threading, making it suitable for both novice and professional users. Each tap has an overall length of 66 mm and a shank diameter of 6.3 mm, conforming to the ISO Taps standard for sizing and accuracy.

Both taps are supplied in robust polypropylene tubes to protect cutting edges during storage and transport. The hand tap is intended for manual use and is compatible with a variety of handle types. Its right-hand threading direction matches standard UNC thread requirements. The HSS material composition offers a blend of toughness and hardness, making the taps ideal for repeated industrial use in mechanical maintenance, fabrication, equipment assembly, and repair shops.

The design features straight flutes, ensuring optimal removal of chips and debris during the threading process. This geometry is well-suited to threading operations in blind or through holes and is especially valuable in industrial and workshop environments requiring precise thread production.

Typical applications for the RS PRO 1/4 UNC Thread Tap Set include machinery maintenance, prototype manufacturing, general workshop threading, metal fabrication, pipe fitting, and fastener installation. The taps’ construction and reliability deliver consistent results across these demanding use cases.

This tap set meets ISO standards for threading tools, ensuring compatibility with worldwide industrial practices. Each set includes: 1 taper tap (4° chamfer angle) and 1 plug tap (23° chamfer angle), providing progressive, high-quality threading capability for maintenance professionals, machinists, and industrial users.

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