History > Patents
he invention of the patented "Schraubenfeder" screw spring fastener in 1926 developed into a star seller, after decades with a frequently changing and expanding product range.
The "Schraubenfeder" fastener formed the basis for the now nearly legendary "high-tension Fe 6 spring washer", which has served to secure rail to sleeper on the German state railways. Ever faster trains demand different fastener systems, leading to the introduction of the Fe 6 in the mid-nineties.
