Lapping

Lapping is a machining process, in which two surfaces are rubbed together with an abrasive between them, by hand movement or using a machine.

This can take two forms. The first type of lapping (traditionally called grinding), involves rubbing a brittle material such as glass against a surface such as iron or glass itself (also known as the "lap" or grinding tool) with an abrasive such as aluminum oxide, jeweller's rouge, optician's rouge, emery, silicon carbide, diamond, etc., between them. This produces microscopic conchoidal fractures as the abrasive rolls about between the two surfaces and removes material from both.

The other form of lapping involves a softer material such as pitch or a ceramic for the lap, which is "charged" with the abrasive. The lap is then used to cut a harder material — the workpiece. The abrasive embeds within the softer material, which holds it and permits it to score across and cut the harder material. Taken to a finer limit, this will produce a polished surface such as with a polishing cloth on an automobile, or a polishing cloth or polishing pitch upon glass or steel.

Lapping (magic)

In the art of conjuring, lapping refers to a set of techniques whereby a performer seated at a table can secretly dispose of an item into his/her lap. A common lapping technique is to sweep an item into the lap while pretending to pick it off the tabletop.

Conflicts

Two issues with lapping:

Features

Subtle uses of lapping, such as secret switches or disposing of secret devices, enable effects that would not otherwise be possible. Stand-up magicians, such as "table-hoppers" at restaurants, may need to use a Topit or other device to obtain a similar effect, due to their inability to lap. The magicians who utilize the trick of lapping are able to manipulate items on a surface to the edge. From there they can move the items so that it falls in their lap without the audience noticing.

Notable magicians

The magician Slydini was particularly noted for his brilliant lapping technique, which relied heavily on subtle misdirection.

Lapping (disambiguation)

Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine.

Lapping may also refer to: