228, or fluted nails, are used to fasten together two pieces of wood by driving the fastener so that one-half of it will be on each side of the joint.

Their size is indicated by the length and the number of corrugations, as 1/2", four.

They are often useful where nails are impracticable.
_Glaziers' points_ are small, triangular pieces of zinc, used to fasten glass into sashes.
SCREWS (a) _Wood-screws_, Fig.

229, may be classified by the material of which they are made; as, steel or brass.

Steel screws may be either bright,--the common finish,--blued by heat or acid to hinder rusting, tinned, or bronzed.