What is a surface grinder? It is an abrasive tool used to create a flat surface on flat surfaces like stainless steel or aluminum. It is an extensively used machining procedure where a rotating diamond-tipped wheel containing abrasive material cuts chips off of a hardworkpiece, creating a rough (or ‘planar’) surface of it in either direction. These discs are then alternated, and a second disc, the ‘lateral disc,’ is added, driving the abrasive material deeper into the work. This is a repetitive, but speedy procedure that results in a perfectly flat surface that can be polished.
The surface grinder is available as a stand-alone unit, which includes all the necessary tools for the operation; or as a ‘drill and polish’ machine that uses a mounted attachment to the machine. The stand-alone unit can be purchased and installed by the customer. The installation process involves mounting the abrasive wheel in the grinder base, turning the handle in the clockwise direction to lock the working wheel into place, and using the supplied rubber and plastic shield to protect the work from the grinding dust, which can otherwise enter into the metallic core of the piece. On a small bench top, a thin polishing pad can be used to apply a very rough finishing process, including removing burrs, grinding a given area many times, or smoothing the work with a hand grinder tool. After the work is finished, the polishing pad can be removed, and the blade can then be safely removed, cleaned, and polished.
Most modern surface grinders employ solid steel blades coated with a chrome or nickel-zinc oxide covering, along with a grinding roller and a grinding cup. These enable the grinders to effectively polish even the most irregularly-shaped workpieces, while preventing any metal flaking through the work. A grinding plate, which has the same width as the workpiece and is fixed directly onto the table, is also available from some manufacturers. The most efficient of these grinders utilizes a dual grinding operation and grinds the workpieces at once.
There are two basic types of surface grinding: wet and dry. Wet surface grinding involves the application of a thin layer of abrasive material to the worktop, usually via a dedicated grinding device, which then applies and grinds the abrasives against the surface of the workpiece. In dry surface grinding, abrasives are applied and then grinded against the worktop immediately after the surface has been compressed. In both cases, grinding speeds are variable, and the results can be extremely varied.
Magnetic Chuck: A magnetic chuck can be mounted on a stand or be easily attached to a drill press. As its name indicates, its function is to grind fine areas beyond the reach of a standard grinder blade. A number of manufacturers make specialized magnetic grinding wheels with diamond corners and other unique features to work on delicate metals. These wheels use a magnetic force to grind the workpieces, although this force can also be used manually.
Diamond Plate: This type of surface grinding wheel is similar in concept to a diamond saw. However, it operates in a slightly different way, as the diamond grinding wheel cuts across a surface, rather than across a grind. Diamond plate grinders generally consist of two plates, with one positioned above the workpiece and the other positioned below it.