The people working with metal quite often should face need of cutting of round preparation from metal sheet. On production this problem is solved simply – by means of oxygen-gas, plasma or laser cutting. Each type of these operations requires the specialized equipment which to have in private use is not present any reason. Therefore in the conditions of private workshops the circle from metal is cut out in different ways – taking into account the available equipment.
- - gas-cutting equipment;
- - welding machine;
- - grinder;
- - electric drill with set of drills;
- - sharpening machine;
- - manual lever scissors;
- - core;
- - dividers.
1. Nakernite on steel sheet the center of circle so that it was spaced from sheet edges at distance, slightly bigger, than circle radius. Put dividers leg in trace from core and draw circle of necessary diameter on metal.
2. The most widespread and technological way is cutting of metal by means of gas cutting. That the circle was well visible, circle the contour drawn by compasses with marker or chalk. Light the cutting torch, adjust flame and carry out cutting of metal on the designated circle. Theoretically, thickness of metal which can be cut by means of gas cutting is 250–300 mm. Practically it is necessary to face such thickness extremely seldom.
3. It is possible to cut out circle from steel sheet by means of electric welding. Light welding arch in any point of the planned circle and hold electrode on the place until the opening is not burned in leaf. After that begin to melt opening edge, starting up electrode on nacherchenny circle. Low-power welding machines, the exploited private owners, it is possible to cut metal of rather small thickness – at most 4-5 mm. Edges from cutting turn out uneven and melted off, and the cut preparation has irregular shape which has to be brought to round by processing on turning lathe or manually – on grinding circle.
4. Simple, but quite labor-consuming operation is represented by circle cutting "Bulgarian". Cut through in leaf of nacherchenny circle of the line, located on tangent to it from all directions. The more the number of lines machine cuts, the closer approaches form of the cut figure circle. But anyway it will be not circle, but polygon which should be brought to circle on the sharpening machine.
5. The circle can be cut out from the sheet of metal up to 3-4 mm thick by means of manual lever scissors. In the beginning cut square with the circle entered in it, then cut off preparation from all directions, starting up edges of scissors on lines, tangents to circle. The finally length of tangents and big - their quantity will be smaller, the smaller work will be required when grinding preparation on the sharpening machine.
6. The most labor-consuming way of cutting of circle is drilling on its perimeter of openings. But sometimes, in the absence of other opportunities, it is necessary to resort also to this way. From the same center from which the initial circle is drawn draw one more with diameter, big diameter available at size diameter of drill which will be used for drilling (usually 4-5 mm). Make stippling on this circle so that deepenings were spaced from core from each other at distance of diameter of drill. Drill in nakernenny places of opening on all perimeter of circle. Beat out the hammer or sledge hammer circle from leaf, process it on outside diameter on the sharpening machine.