5Pcs/Set Countersinks Countersink End Mill Drill Bit Bits Tool M3-M8 4 Flutes HSS-ALrect: Countersink End Mill is a specially made tool mainly used for cutting such a hole allows for the head of a screw or bolt. This kind of cutting hole and bottom hole with high alignment precision, because of its high production efficiency, is widely used in the machining industry. Features:1. The cutters are made of hard high-speed steel, usually used for mounting on a milling machine.2. Suitable for milling copper, aluminum, steel, cast iron, etc.3. High strength, abrasion resistant, fast cutting for high hardness.4. It can process directly or fine heat treatment mold processing.5. It reduces the times of tool change, improves the actuator movement of the machine efficiency and saves the time of creating molds. Specifications:Material: HSS-AL Super Hard High Speed SteelHardness: HRC65 - 68°Size:(Boot*Blade Diameter*Shank Diameter*Full Length)M3=3.2*5.9*6*45mmM4=4.2*7.4*6*48mmM5=5.2*8.9*6*51mmM6=6.2*10.4*8*58mmM8=8.2*13.4*12*67mmWeight: 128g (Approx.) Package Included:5 pcs. x countersinking cuttersNote:1. Please allow 1-2mm error due to manual measurement. Thank you for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take real in standard.1) we accept Alipay, West Union, TT. All major credit cards are accepted through the payment processor's secure escrow.2) payment must be made within 3 days of placing the order.3) if you are unable to check out immediately after the listing ends, please wait a few minutes and try again, payments must be completed within 3 days. About Shipping1.