Drill HSS Co Cobalt NC Center Bit 60 90 120 Degree Location Prepare Guide Pilot Hole CNC Machine Tool M35 M42 1-20mm(10mm)

Drill Bit SetsSpotting Drills-60 90 120 degree drill point.TiN coated HSS:-For mild steel and other soft metals.-Manual grinding.-It's not only as a center drill but as a chamfer tool as well .-For accurate spotting on Machines.-Precise drill positioning.-Short lengths and no body clearance make this a very rigid tool.In order to reduce factors that are not good for machining such as uneven part surfaces or slightly used drill bits a simple way to avoid "slipping" is to use a fixed-point drill. The tool is designed to leave a dent on the surface of the part so that the drill bit can be engaged during the drilling process and maintain its correct alignment to prevent the drill bit from deviating from the route.GeometryThe shape of the spot drill is short and thick the chip removal groove is very short and the alloy centering drill with excellent rigidity has better effect. Its drill tip geometry is just enough to drill a shallow hole on the surface of the workpiece; Compared with standard drills the centering drill has a very thin chisel edge which can effectively cut the workpiece material.Dimensions-Long Length of HSS:d3*100Ld4*120Ld5*120Ld6~16*150L-Long Length of carbide:100mm4PCS :3mm 4mm 5mm 6mm5PCS :3mm 4mm 5mm 6mm 8mm6PCS :3mm 4mm 5mm 6mm 8mm 10mm7PCS :3mm 4mm 5mm 6mm 8mm 10mm 12mmMachining parameterHSS:RPM:150~1100 Feed:0.06~0.2Carbide:RPM:650~2500 Feed:0.08~0.2Whether the cutting speed and feed rate are appropriate depends on the workpiece material the insert substrate and the coating as well as the requirements of the drilling process itself.In general the cutting speed and feed rate of centering drilling should be lower than that of secondary drilling. The purpose of centering drilling is only to provide a correct starting hole position for secondary drilling so it is not necessary to achieve a high drilling rate.TestingDrillingBefore the drilling process first use a spot drill to drill hole with a depth of 1 to 2 times the diameter to ensure the accuracy of the drilling process of ordinary drill bits and reserve chamfers for tapping to facilitate tapping.The drill tip angle of the centring bit shall be equal to or greater than the drill tip angle of the secondary bit. This can eliminate excessive cutting pressure on the cutting edge of the drill (this pressure will cause the tool to fail in advance and reduce the quality of the hole).When both the centering drill and the drill bit use the same drill tip angle the drill tip and cutting edge of the secondary drill bit will cut into the workpiece at the same time. This may cause flutter due to the same cut-in angle which may cause secondary bit chipping.For carbide drill bits it is correct that the tip angle of the fixed point drill should be greater than the tip angle of the secondary drill bit. However for high-speed steel secondary drills we hope that the cutting edge can cut into the workpiece before the drill tip. Because the cutting edge of the high-speed steel drill bit is not as fragile as the carbide drill bit we hope that the cutting edge will contact the workpiece before the chisel edge and the drill tip will not participate in the cutting.Carbide drill is just the opposite. Cemented carbide drill bits are usually designed to reduce the chisel edge. Due to the brittleness of cemented carbide we do not want the cutting edge to cut into the workpiece first. Therefore it is recommended to use a centering drill with a larger drill tip angle so that the chisel edge can be cut into the workpiece before the cutting edge.==========High-concerned chemical : NoneOrigin : Mainland is_customized : YesModel Number : Spot DrillDIY Supplies : MetalworkingMaterial : High Speed SteelType : Center Drill BitUse : Metal DrillingLength : 50 to 115mmPoint Angle : 60° 90° 120°

• Drill Bit Sets
• Material:Crafted from M35 M42 HSS Co Cobalt these spot drills offer superior durability and precision.
• Multi-Size Selection:Available in sets of 3 4 5 6 8 10 and 12mm these spot drills are ideal for various metalworking tasks.
• Precision Drilling:SIQI spot drill bits ensure accurate positioning for precise metal drilling with a CD-ROM speed.