This section is from the book "A Practical Treatise On The Joints Made And Used By Builders", by Wyvill J. Christy. Also available from Amazon: Practical treatise on the joints made and used by builders.
This is sometimes found in the heads of circular window frames, the radiating joints being tightened up and held together by means of a key of hard wood with both extremities thickened out, and somewhat resembling in shape the head of a framing hammer.
Usually a butt joint secured with a joint screw, otherwise handrail screw, which has a right and left hand thread each working in a nut with notches, both the nuts being buried in holes sunk near the ends of the two lengths of rail. By turning the nuts the joint is tightened up, after which the holes are stopped with pieces of wood to match, and the mouldings of the handrail finished off with handrail planes. Sometimes, however, the connection is made with a splice joint, which is a species of scarf, the planes of junction being horizontal and vertical when the rail is in position.
Heading Joint is formed between lengths of handrails, and of boards, etc, connected end to end, and is either square, cross grooved or tongued, splayed or bevelled, rebated and tongued, or forked. In dados and similar glued-up work it is glued.
A general term for many joints that turn or, in other words, that open and close by means of ligaments of any degree of plainness and elaborateness called hinges (alias gemmels in mediaeval times) which are fixed on or near the surfaces of contact either to bring them together or to part them as desired. Hinging and hanging are with the joiner almost correlative terms. To make a door swing easily and not expose the inside of a room when open whilst it will shut close without sticking, is a good test of a good workman. The whole subject of hinging is so enticing and interesting that it will be expedient to pass on at once to the next joint.
This is formed when the rebates of the meeting stiles of a casement are worked out with a curved groove so as to interlock, as shown in Fig. 113, for the purpose of keeping out rain. Two fillets, however, fixed inside and outside to opposite stiles is a more secure arrangement, whilst a single one on the outside, ornamented with a cocked bead, is often adopted and deemed sufficient.
This is the same in principle as that made by the carpenter, but there are a few points of variation that require noticing. Instead of the whole or nearly the whole end of a piece being housed in, as is usually the case when that artificer makes a joint of this description, or indeed as happens when the joiner himself lets skirtings into architraves, blocks, etc, there are occasions in joinery of frequent occurrence that necessitate only about half and not the full thickness of a moulded board, etc, being housed in, as when skirtings are housed at a re-entering angle. On the other hand, sometimes more is hollowed out of one board than is merely required for the thickness of the other, as, for example, when steps are housed into strings, for here the grooves or housings are cut large enough to take the glued wedges also. Again, the edge of a board for its whole length and full thickness may be housed into the face of another, as instanced by the joint not unfrequently made between the inside lining of a sash frame and the soffit of the window lining.