Pioneered by Bristol, the multiple spline drive system is recognized by design engineers as the superior method of transmitting torque because nearly 100% of wrenching force is applied at right angles to the load bearing spline surfaces of the socket. Other drive systems dissipate a significant amount of force into radial thrust tending to expand the socket rather than tighten the screw.

Bristol Spline Drive Suggested Applications

  • Excellent for all applications.
  • Especially indicated for set screws and smaller cap screws requiring severe tightening, and for screws with shallow sockets.
  • For frequent removal and resetting of screws and plugs, such as for tool inserts, purge screws, drain/filler plugs, template retainers, and replacement of worn parts.
  • In applications requiring softer screws such as stainless steel or non-ferrous materials.
 Advantages of the Bristol multiple spline drive system vs the hex drive system for socket screw wrenches

The substantial and effective wrench engagement inherent in the Bristol design addresses the problems caused by other systems such as cam-out, socket reaming and "rounding" of wrenches.


Adequate for many applications, other drive systems such as this common hex design are not as positive or effective methods of transmitting torque as the Bristol Spline configuration. To increase performance and durability, Bristol Wrench manufactures hex wrenches in sizes .028" through 3/8" diameter and larger from precisely shaped 8650 steel.
        Call us for specials and standards.

Hex Drive Applications
  • Adequate for many applications where some loss of tightening force into radial thrust can be tolerated.
  • Not recommended when severe tightening of small parts is required.
  • Not recommended when frequent removal and resetting is required.
  • Not recommended for use with softer components.