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110 in water at a temperature not exceeding 80°F. Rivets are tested by being bent cold until they are completely doubled up without fracture, and the heads must be hammered flat without cracking.

The specified tensile and bending tests differ according to the material concerned. In the case of plates there is always sufficient excess material at the sides from which a test specimen can be cut, so that each plate can be tested if required. In the case of straight axles and tyres which are tested to destruction the inspector selects any two per cent. of the number ordered, and the quality of the whole lot is decided by the behaviour of those so selected.

Impact Tests. In addition to tensile and bend tests, axles and tyres are also subjected to the “falling weight test.” The test axle is placed upon bearings which are placed at a distance apart varying from 3 ft. for an axle 4 ins. diameter at the centre, to 5 ft. for axles 6 ins. or more in diameter, and a weight of 1 ton is dropped on to the centre of the axle from a height varying from 16 ft. for the 4 ins. axle to 35 ft. for the 6 ins. and larger axles. The axle must withstand five such blows without breaking. Under the first blow it bends, and is then turned over to receive the next blow, this being repeated each time. If it stands this test the axle is finally broken.

Tyres are tested in a similar manner by being placed on edge, a 1-ton weight being then dropped