How to sharpen drills

How to sharpen drills

There is no such house handyman who in the work would not use drill. It is a pleasure when you work with well ground tool. However drills, as well as other cutting tools, have property to wear out and be rebated, need for repeated sharpening of the tool that's when appears. It is better to entrust it to professionals, but there are situations when sharpening has to be done independently.

Instruction

1. Apply grinding stone from carborundum to sharpening of the tool. This grinding stone is classified by various shades, for example, gray, green is intended for sharpening of solid alloys, red, is necessary for work with products from quick cutting steel. In life drills in the form of spiral which have extensive range of application are generally used. Thanks to the spiral configuration, they successfully cope both with solid steel, and with soft wood. At introduction of drill in any material the cutting edge cuts off layer of material and gives it on drill spiral in opposite direction that interferes with contamination of cutting edges.

2. Sharpening of drill needs to be begun with receiving the correct form of cutting edges, rather spiral grooves on which shaving is taken away. The drill needs to be held so that the rotation axis of grinding circle was parallel the sharpened drill edge. It is necessary to remove metal from back surface until light reflected from cutting edge does not cease to be perceived by eye. Similar operation is required to be done also with other edge. The corner between cutting edges, depending on range of application, fluctuates ranging from 90o up to 140 lakes. For tree and plastic it makes 90o-100o, for duralumin 110o-120o, steel is drilled drill with the angle of sharpening to 140 lakes. Drills with the universal angle of sharpening 120o degrees appear in retail trade. Undoubtedly to receive the necessary size corner without certain experience quite difficult. Therefore you will be helped by the template which is cut out from dense paper or cardboard.

3. When sharpening it is necessary to watch that the axis of drill coincided with its top, and length of cutting edges was the identical sizes. At observance of these parameters the ends of cutting edges have to describe identical trajectory. After alignment of edges, we start processing of their back surfaces. Their processing consists in giving of conical form to them. We hold drill so that the plane of edge was parallel to cylindrical surface of grinding stone, and drill axis at an angle to it. When processing back surfaces be careful not to touch opposite surface, use cylindrical surface of grinding stone closer to face. And the last operation of sharpening of drill is finishing cutting edges. Width of the cutting plane has to be within 0.2-0.3 mm.

Author: «MirrorInfo» Dream Team


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