Welcome to Stoffel Polygon Systems, Inc.
ISO CERTIFIED (Certificate Number 15459)
Polygon Splines (Shafts and Hubs) go back in history to the stone ages, when shafts and wheels were hand crafted with polygon shapes, and fitted together for transmitting torque. The polygon drive connections remained in mind of design engineers, until they were developed by Austria, during the WWII, then they were transferred to Germany, and France. In Germany, the DIN Standards included data for three-and four- sided metric polygon connections (Din 32711 & 32712). These Standards data were converted to inch dimensions, and introduced to the United States by Stoffel Polygon Systems, Inc. and were published in the 23rd Machinery's Hand Book and its later editions.
Polygonally shaped shafts and bores present many advantages in applications calling for fixed or sliding drive connections. These advantages stem primarily from greater load carrying capacities for a given length and diameter of connection as compared to splines, keys, flats, or other common drive connection arrangements. On sliding drive connections, they provide for smoother movement with less allowance for sliding clearance, reducing backlash and being capable of withstanding greater shock loads under extreme torque reversal conditions, such as occur on brakes, transmissions, etc
Polygons, The Ultimate Strength of Drive Connections
It will be readily seen that polygon shafts and hubs provide the highest torque carrying capacity, within the shaft diameter, of any drive connection now known. This has been demonstrated by torsion bar test to the failure point as illustrated in the photo below.