The solid carbide gun drill makes of a solid alloy (drill point, drill pipe, and drill shank integrated). This design can ensure higher reliability and cutting performance. At the same time, it has higher rigidity, and higher Low torsion vibration can make the tool life longer, it is a cash and efficient deep hole processing tool.
However, gun drills are most prone to wear problems, and only after precise regrind can the processing performance of gun drills be ensured. This article will take the widely used carbide gun drill as an example to teach you how to regrind the gun drill.
Blunt standard of carbide gun drill
To extend the tool’s life to get the best results, the user must follow the mandatory grinding standards, as shown in the table below. Develop a blunt standard. When the back wear of the outer edge of the carbide gun drill exceeds the value in the table below, the gun drill must regrind to prevent the cutting force from breaking.
When the wear on the back of the tool reaches the following dimensions, it should be re-grinded: When the flank wear of the drill bit with a tool diameter of <=15mm (0.591 inches) reaches 0.2～0.4mm (0.0079-0.0158 inches), it needs to reground; >15mm, even when the flank wear reaches 0.4～0.6mm (0.0158-0.0236 inches), precise regrind is required.
Gun drill regrind tool
Cemented carbide gun drill regrind mainly uses a gun drill grinder and tool sharpening fixture.
Gun drill grinder
Adopt a precision rolling guide and high-speed motor. Work movement is stable, and friction is small. The grinder can rotate in horizontal and vertical planes. You can use the sharpening fixture to sharpen the gun drill accurately and efficiently.
A sharpening fixture is a unique high-efficiency tool for gun drill sharpening. It has a compact structure, convenient clamping, and simple adjustment. The sharpening of all angles can complete in one clamping, which saves time. The drilled edge has high strength and functional precision.
The standard grinding angle of carbide gun drill
- The standard grinding angle of the single-edged gun drill with D<=5.00mm
- 2.5.00mm<D<=20.00mm single-edge gun drill standard grinding angle
- 3. The standard abrasive edge of the single-edged gun drill with D>20.00mm
Precautions for regrinding carbide gun drills
- The grinding of the gun drill should force grinding regularly. When the wear on the back of the tool reaches the blunt standard, it should regrind.
- As the gun drill is a precision tool that works under unfavorable conditions, the blade’s geometry must be kept in the best position. Therefore, when grinding, a sharpening jig and a special sharpener are required, and the drill cannot sharpen by hand.
- When grinding, the force direction of the drill should be toward the tool pad to prevent the tool from being damaged by the shaking of the drill rod. Do not feed too much each time to prevent the carbide drill bit from rupturing and breaking, which will eventually cause personal injury.
- After grinding the five facets of the drill, you need to use a grinding wheel to smooth the edges and corners between the face and the guide part of the training.
- The gun drill needs to be re-grinded on a particular diamond grinding wheel. The dual-function grinding wheel can achieve two functions of coarse and fine grinding.
- Please wear protective glasses and masks to prevent damage to your body caused by the dust generated by the hard alloy part of the sharpened gun drill.
The above are the regrind techniques and precautions of carbide gun drills. Gun drills are precision machining tools, so sufficient attention must be paid to the specifications to maintain excellent gun drill performance.