(4) Machine.
For good, sound work, machine riveting is the best.
Snapped riveting is next in quality to machine riveting.
Countersunk riveting is generally tighter than snapped, because
countersinking the hole is really facing it; and the countersunk rivet
is, in point of fact, made on a face joint. But countersinking the
hole also weakens the plate, inasmuch as it takes away a portion of
the metal, and should only be resorted to where necessary, such as
around the front of furnaces, steam chests or an odd hole here and
there to clear a flange, or something of that sort.
Hammered riveting is much more expensive than machine or snapped
riveting, and has a tendency to crystallize the iron in the rivets,
causing brittleness.
In the present state of the arts all the best machine riveters do
their work by pressure, and not by impact or blow.
The best machines are those of the hydraulic riveting system, which
combines all of the advantages and avoids all the difficulties which
have characterized previous machine systems; that is to say, the
machine compresses without a blow, and with a uniform pressure at
will; each rivet is driven with a single progressive movement,
controlled at will.
Pages:
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42