Chaplet
The Encyclopedia of Founding (1892)
A chaplet proper consists of a stem of indefinite length, terminating at one end with an increased flat surface, which renders it less likely to be thrust into the core by pressure or weight. If this plate end is forged out of the whole piece the chaplet is a good one, and may be relied upon; but a riveted end is an abomination for more reasons than one. In the first place they are apt to slip through unless the shoulder is enlarged, and that is not sufficient to prevent the head from flying off when struck; consequently, whether they are home-made or purchased from the dealers, the solid ones are to be preferred. By means of a match-plate very many excellent chaplets for ordinary purposes may be made of cast iron; for many jobs they are infinitely superior to wrought iron, and very much cheaper. Chaplet is the general term for almost every device for holding down or supporting cores and sections of moulds; even springers are recognized as a species of chaplet, and so called in many parts (see SPRING-CHAPLET), and solid studs of almost every description go by this name. Two important features in this connection are rust and lack of material. Both of these conditions are fatal to a mould--the former because of the large amount of gas evolved when the rust decomposes; the latter because of their too frequent use in parts where the current of metal dissolves the stud, leaving the part without support. Both studs and chaplets are incorrectly called anchors in some foundries. See ANCHOR.
What Has Changed in the Last Century
The 1892 account's core advice still holds: chaplets are the studs and plates that hold a mould's core in place until the metal arrives, and foundrymen still prefer a solid one-piece head to a riveted one that can fly off under the rammer. What has moved is the material and the finish. Where the 1892 writer weighed cast iron against wrought iron, modern chaplets are almost always drawn or stamped low-carbon steel bought in standard sizes from suppliers, and they are commonly tinned, copper-plated or otherwise coated — precisely to answer the two dangers the entry names, rust giving off gas and the stud dissolving in the stream of metal. The larger change is that many castings which once needed chaplets at all are now made by processes the writer never saw: die casting, investment casting and lost-foam, in which the core is either unnecessary or supported by other means, while computer simulation of mould filling now predicts where a support will be washed away.
Written for this edition, 2026.