Folk crafts, a funnel and a grater

A technological process is the part of production that turns a blank into a finished item. It divides into operations; an operation is a complete job done at one work place without changing the tool, such as cutting, filing, drilling or riveting. An operation in turn divides into passes in which the tool and the surface being worked do not change. A technological map shows the names of operations and passes, a sketch of the processing, tools and fixtures. To make a funnel, first the cone development is drawn: it is a circle sector whose radius equals the cone’s slant height, and its centre angle is φ = 180° × D : L, where D is the diameter of the cone base and L the slant height. Order of operations: check and straighten the sheet; draw the development; cut with metal shears; smooth edges with a file; bend into a cone; fix the seam. Soldering or riveting the seam is done by the teacher or a master. Cut sheet edges are very sharp, so gloves are worn and the work is supervised. A funnel is for pouring liquid into a narrow container; for food, only a clean metal funnel made for that purpose is used.