This report describes the sutdy of piercing test by punches, 4mm in diameter, with wedgeshaped and coniform ends. Wedge and cone angles of punches are varied between 0° and 45° Specimens are steel and brass sheets of 4 mm and 1 mm in thickness.
Then following results are gained.
1) In piercing a sheet of 4 mm in thickness, the increase of primary loads at wedgeshaped and coniform end punches is smaller than at flat end punches, and penetration at former is larger. The larger the wedge and cone angles of punches, the more remarkable those phenomena.
2) The maximum load in piercing a sheet of 4 mm in thickness, is generally larger in case of wedge-shaped and coniform end punches than of flat end punches.
In the test of wedge-shaped punches with angles larger than 15°, the maximum load is approximately constant. In the test of coniform end punches, the maximum value of the maximum load exists at a certain cone angle in the maximum load-wedge, cone angle diagram. On piercing a sheet of 1 mm in thickness, corresponding to a certain value of the wedge angle, the maximum loads begin to decrease suddenly by the effect of shear angle, and at a certain value of the coniform angle, the maximum value of the maximum load exists.
3) And others.