Features 1、These center drill set are made of high speed steel, high hardness and durable in use 2、Each center drill has a double end and with standard milling Angle 60 ° 3、The center is used to make tapered holes for the center of the lathe in order to keep the standard twist drill in place so as to prevent the screw from slipping or deviating 4、Used for parts that need to be machined between production centers or work piece center holding 5、Prefabricated precise positioning for hole processing, guide the drill for hole machining, so reducing error, center hole machining for the end surface of the shaft and other parts Specification Features: Transistor is a basic semiconductor device that control current, which can also be used as a non-contact switch. There are total 200 pieces of transistors in 10 values in this set which will meet you basic needs. All transistors are well packed and assorted in a transparent box for convenient storage. Each transistors is clear marked so you can easily identify which type of transistors you need. This is a great assortment of transistors for electronic professionals or enthusiasts. Specifications: Material: Silicon Type: BC337, BC327, 2N2222, 2N2907, 2N3904, 2N3906, S8050, S8550, A1015, C1815 Quantity: 20pcs each type Package Includes: 1 Box x Transistors Note: Transistors are sorted manually, so there might be small mistakes on type and quantity. Thanks for your understanding. Package List