. American engineer . rivet may be handledmore easily than a hot one and may be placed in positionwithout fear that it may become cold and the head chip uniform heat is obtained, expansion is uniform and whenthe proper degree of temperature is secured for the rivet it isheaded, so that the fibers are not injured by overheating,stretching, too rapid cooling, etc. It is also claimed that thedifficulty experienced when rivets are hammered until they arecold is entirely eliminated, as there is no necessity of formingthe head until the rivet is at exactly the right temperature, whenit is auto
. American engineer . rivet may be handledmore easily than a hot one and may be placed in positionwithout fear that it may become cold and the head chip uniform heat is obtained, expansion is uniform and whenthe proper degree of temperature is secured for the rivet it isheaded, so that the fibers are not injured by overheating,stretching, too rapid cooling, etc. It is also claimed that thedifficulty experienced when rivets are hammered until they arecold is entirely eliminated, as there is no necessity of formingthe head until the rivet is at exactly the right temperature, whenit is automatically headed. Calking is seldom required in thisprocess, because the method produces a gradual heating of therivet which swells and fills the rivet hole uniformly and fullywhen headed, so that inequalities in the plates are filled withthe hot metal. The manufacturers state, however, that wherecalking is required it may be done more safely and easily ifthe electrically heated ri\et is used on account of there being. no brittleness to the rivet or head because it has not beenhammered while cold, or nearly so. The difficulties of giving a proper heat to the rivet are alsoovercome because the temperature may be completely con-trolled. If desired, the machines are arranged so that theycannot heat the rivets above 1,300 deg., or if a higher temper-ature is needed 1,450 deg. to 1,500 deg. may be given. Themachines are made with a series of heats known as variablespeeds, so that by moving a small hand switch from one pointto another a greater or less degree of temperature may be in-stantly secured; on one heat or speed they will rivet a smallrivet, while on the next speed a larger rivet may be used,each speed having a maximum size of rivet which it will handleproperly. Another point upon which stress is laid is that therivets do not become chilled by being brought into contactwith the cold plates while cooling. There is no necessity to anneal cold made rivets, as they areheated and
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroa, bookyear1912
