Tuesday, January 19, 2010

Pozi Drive - Phillips not GM

By now you have probably figured out that there are different size Phillips screws and bit. Good Job. But did you know that there are more than one type of Phillips screw and drivers.

If you are a ski bum you know that a #3 Phillips screw driver is best for turning those large screws on your skis. Be it the DIN setting or the mounting screws. If you have a keen eye you might notice that the face of the screw might have a few extra lines than the standard four found on Phillips screw head. Four standard slots and four additional "star burst" set of 45 degree angles. This is known as Pozi Drive or Suredrive screw.

A joint patent for this design is held by the Phillips Screw Company and the American Screw Company. The purpose of this screw is to increase the torque which can be applied before the screw and driver interface "slips".

A regular screw driver can be used to turn Pozi screws however a Pozi driver should not be used to turn non-pozi Phillips screws. The four extra spline will prevent the pozi driver from sitting properly with in the screw and cause rounding of the four Phillips slots.

The term Pozi Drive is often confused with Posi-Trac. Posi Trac is General Motor Companies term for a limited slip differential. LSD not the screws on your skis.

The American Screw Company...Imagine all the marketing material you can come up with for those guys!

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