Hole saw
A hole saw is a in conjunction with a drill used saw , can be cut with which circular holes limited depth in different materials.
Structure and application
The hole saw consists of three components: a mounting plate, which accepts saw blades and centering drill, a drill , which is clamped in the center of the mounting plate and is used for centering, and a saw blade of the desired diameter . The mounting plate can have its own shaft with which it is inserted into the drill chuck of a drilling machine, or the center drill sits in the drill chuck and the mounting plate is attached to it with a clamping screw.
The hole saw enables large-caliber, precisely fitting holes , for example for pipe penetrations, sockets and switch boxes in wood , insulating material and plasterboard . Only a small amount of material is removed, as only a centering hole and a circular saw cut are created in the material to be machined. The maximum possible depth of the hole results from the height of the saw blades used.
A mounting shaft usually includes 6 to 8 saw blades for different hole diameters. The saw blade to be used is inserted into the corresponding groove of the mounting plate and fixed there by means of a bayonet lock or by several threaded pins. There are also hole saws with only one saw blade, which is then firmly screwed to the mounting plate and allows holes of a certain size to be drilled safely (e.g. for sockets). The hole saw can only be used in one direction of rotation , as the saw blades only cut in one direction (usually clockwise rotation); the bayonet locks would also open when turned in the opposite direction.
Another design, which allows a stepless change of the hole diameter, is shown in the illustration opposite.
Working with hole saws places increased demands on the torque of the drill.
Spot weld milling cutter
The spot weld cutter is a special type of hole saw. It consists of a clamping shank in which a center point is resiliently mounted, and a small drill bit screwed onto the shank. The diameter of the holes is roughly the same as that of a spot weld, i.e. typically between 5 and 10 millimeters.
The spot weld cutter is used to open a spot weld joint between two pieces of sheet metal, i.e. H. drilling away the welding point in the upper sheet without perforating the sheet below. When drilling open the welding point, the centering point does not penetrate the sheet metal, but the drill bit cuts through the material around the welding point down to the lower sheet metal.
literature
- Håvard Bergland: forging knives . A Norwegian Art, 2nd edition, Verlag Th. Schäfer, Hannover 2004, ISBN 3-87870-661-8 .
- JG Geißler: The turner or practical teaching term of the common & higher art of turning . First part, by Siegfried Lebrecht Crusius, Leipzig 1795.
See also
Web links
- Drilling circles from wooden board with adjustable hole saw (accessed November 10, 2016)
- Hole saws (accessed November 10, 2016)
- DRILLS, HOLE SAWS, DIAMOND TOOLS (accessed November 10, 2016)
- HSS bi-metal hole saws (accessed November 10, 2016)