Usage of drill bits

A drill bit is a tool used to drill through or blind holes in solid materials and to expand existing holes. Commonly used drills are mainly twist drill, flat drill, center drill, deep hole drill and nesting drill. Different bits have different functions. How to use them? What problems should be paid attention to in the use of drill bit?

bit

Use of drill bit:

1, the drill should be installed in a special packaging box, to avoid vibration collision.

2, when using, take out the drill from the packaging box should be installed into the spindle spring chuck or automatic replacement of the wood drill set tool store. Put it back in the box.

3. Non-contact measuring instruments such as tool microscope should be used to measure the diameter of drill bit, so as to avoid the cutting edge being bruised by contacting with the mechanical measuring instrument.

4, some nc drilling machine using the locating ring nc drilling machine, do not use the locating ring, such as using the depth of the locating ring of the installation location must be accurate, if you don't use the locating ring its bit loaded on the spindle elongation to adjust, multiple spindle drilling machine more attention should be paid to this, to make each spindle drilling depth. If inconsistent, it may cause the drill to drill to the table or unable to drill through the circuit board, resulting in obsolescence.

5, usually can use 40 times stereoscopic microscope to check the wear of the cutting edge of the hss twist drill bit for metal.

6, often check the spindle and spring chuck concentricity and spring chuck clamping force, concentricity is not good will cause small diameter drill break and large aperture, clamping force is not good will cause the actual speed and set speed does not conform to, between the chuck and the drill slip.

7. The clamping length of fixed handle drill bit on the spring chuck is 4 ~ 5 times of the diameter of drill handle.

8. Check the spindle press foot frequently. Press foot contact surface should be horizontal and vertical with the main shaft can not shake, to prevent drilling and offset hole.

9. The vacuum effect of drilling machine is good. The suction air can reduce the temperature of Hex Shank Taper Point drill bits, and the dust can be taken away to reduce the friction and produce high temperature.

10, the substrate lamination includes the upper and lower plate to be fixed and flattened in a hole and groove positioning system on the workbench of the drilling machine. When using adhesive tape, it is necessary to prevent the bit from sticking to the tape and cutting chips, resulting in chip removal difficulty and drilling break.

11. When ordering drill bits from manufacturers, check whether 4% of them meet the requirements during incoming inspection. And 100% with 10 ~ 15 times the microscope to examine its notch, scratch and crack.

12. Regrinding drill in time can increase the use and regrinding times of drill, prolong the life of drill, and reduce production costs and expenses. The wear depth should be less than 0.2mm over the full length of the two main cutting edges as measured by tool microscopy. For regrinding, grind off 0.25mm. A normal fixed-shank bit can be reground up to 3 times, a bit with a undercut can be reground up to 2 times. The quality and precision of drilling will decrease, resulting in the scrap of the finished circuit board. Excessive grinding is counterproductive.

13. When the wear diameter is reduced by 2% compared with the original due to wear, the bit is scrapped.

14, drilling parameter setting in the general case, the manufacturer provide a copy of the plant in the production of drill bit drilling speed and the speed parameter list, this parameter is only a reference, the actual technology personnel through actual use to draw even a bit conforms to the actual situation of speed and speed parameters, usually have difference between the actual parameters and the parameters of the reference but not too much difference.