| 摘要 |
A screwdriver comprises a metal rod with a handle at one end and a blade at the second end, end projections formed on both sides of the blade for interacting with an outer surface of semicircular screw head, the surfaces of said projections from the side of blade have a concave shape. The concave surfaces of end projections on both sides of the blade have a semi-cylindrical shape. The radius of their rounding is equal to the radius of rounding of the semicircular head of the screw. Depth of formed depressions is equal to the depth of a spline groove at its end and length of the part of blade disposed between them. |
