Specimens of high steel when quenched in a similar manner shall be capable of bending ninety (90) degrees around a circle whose diameter is equal to twice the thickness of the test-piece, and one hundred and eighty (180) degrees, either hot or cold, without showing signs of cracking on the convex side of the bend.

DRIFTING TESTS.

Punched rivet-holes in medium steel, pitched two (2) diameters from a sheared edge, must stand drifting until their diameters are fifty (50) per cent greater than those of the original holes, and must show no signs of cracking the metal.
      High steel must stand the same test, except that the increase in diameter is to be twenty-five (25) per cent instead of fifty (50) per cent.

FRACTURE.

All broken test-pieces for all three classes of steel must show a silky fracture of uniform color.

NUMBER OF TEST-PIECES.

At least three (3) tensile tests and three bending tests shill be made on specimens from different ingots of each melt, except, in the case of small melts, for which the number may be reduced to two (2) or even to one (1), according to the judgment of the Inspector. The bending tests may, if desired, be made on the broken test-pieces of the tension tests. If material of various shapes is to be made from the same melt, the specimens for testing are to be so selected as to represent the different shapes rolled from such melt.

All tests are to be made by the Contractor for the Inspector without charge.

The Inspector will be permitted considerable latitude in respect to the number of tests required, reducing same when the metal runs uniformly and increasing same when it does not.