Metric Thread Size: M3 x 0.5, M4 x 0.7, M5 x 0.8, M6 x 1, M8 x 1.25Thread Length: 17mm / 0.67", 20mm / 0.79", 21mm / 0.83", 25mm / 0.98", 27mm / 1.06"Total Length: 50mm / 1.97", 52mm / 2.05", 56mm / 2.2", 61mm / 2.4", 63mm / 2.48"Square End Width: 2mm / 0.08", 3mm / 0.12", 3.5mm / 0.14", 4.5mm / 0.18", 5mm / 0.2"Accuracy Class: H2Cutting Direction: Right HandPackage Content: 2 Set (10pcs) x Hand Threading Taps ( 2pcs of each size)Descriptions:M3 M4 M5 M6 M8 hand threading tap sets are precision machined to produce accurate threads. Straight groove design of the hand tap can quickly remove chips downward, reduce operating resistance, and achieve efficient processing. The thread is clear and burr-free, which can achieve precise tapping.Hand taps are mainly used with tap wrenches and are suitable for re-tapping damaged or stuck threads, or to create new threads. Used for tapping through or shallow holes in mild steels, aluminum, iron, copper, hard plastic.6542 (M2) high speed steel tap set offers high hardness and excellent wear resistance for durability and longevity, and good cutting performance for clean, precise holes. Designed with basic structure without any coating, suitable for a wide range of applications.Tapping oil has lubrication, cooling and anti-sticking effects. Adding appropriate tapping oil can obtain higher quality internal threads and more durable taps. Please apply anti-rust oil for maintenance after use to extend the service life.Ensure proper alignment, use proper tapping technique, and apply consistent pressure as you turn the tap to achieve clean, precise threads. Periodically reverse while tapping to break up chips and remove debris from the flutes.