Frearson (Reed and Prince) screwdriver bits from Apex Fastener Tools, formally Cooper Tools.
The Frearson recess is designed so that any size bit will fit any size recess. Choose bits on the basis of body diameter the larger the screw, the larger the body diameter. Apex's premium tool alloys and proprietary heat treat help avoid typical problems such as shattering and premature bit wear.
Insert Bits are commonly used with a bit holder in power tool applications. This combination is economical, provides flexibility and allows a fastener to be magnetically held by the bit. Power Drive Bits are placed directly into the power tool chuck.