Fastener having recess useable with multiple drivers and method of manufacture
A fastener is described having a head formed with a recess which accommodates a square head driver, symmetrical drivers, such as PHILLIPS™ style drivers, asymmetrical style cross head drivers, such as POZIDRIV® style drivers, and combination square and cross drivers without compromising performance of the drivers.
1. A fastener having a recess constructed in a head thereof for receiving a driver in torque transmitting engagement, said recess comprising:
a cross slotted portion, extending downward a first distance from a top to a bottom of said recess, said slots being formed by opposing walls, wherein said opposing walls converge symmetrically, from said top to said bottom, at a symmetrically formed included angle having an overall size that is substantially equivalent to an included angle of 2.5 degrees said recess being manufactured in conformity with a standard for type Ia fasteners; and
a square portion, defined by substantially vertical surfaces constructed to extend between said opposing walls of said slots, said square portion extending from said top of said recess downward a second distance that is less than said first distance.
2. A fastener, according to claim 1 , wherein said adjacent opposing walls are each inclined at an angle of 1.25 degrees to the vertical to cause said convergence.
3. A fastener, according to claim 1 , wherein said cross slotted portion has overall cross slot geometry and said square portion, has an overall square geometry, wherein said overall square geometry is constructed within said overall cross slot geometry so that said slots extend below said square geometry.
4. A fastener, according to claim 1 , wherein, within the recess at said second distance, said substantially vertical surfaces extend radially inward to form a bottom of said square portion.