In general terms, rubber washers provide better sealing than O-rings and also resist better to wear thanks to their better behavior against extrusion.
However, because of their widespread commercialization, it is much simpler and cheaper to purchase O-rings or Cord-rings. Therefore, a simple, effective and cheap way to remedy this problem is to use an extruded square section profile. Cut to the desired size, the square cord makes it possible to manufacture washers, either by gluing or by warm-vulcanization.
At JIOrings, we have the most popular sizes in stock: Black NBR70 (Perbunan @) and Black FDA FPM75 (Viton®). On request, we also manufacture the following compounds: Green FPM70 (Viton®), Black CR70 (Neoprene®), Translucent FDA VMQ60 (Xiametre®), Red FDA VMQ70 (Xiametre®), Black FDA EPDM70 (Keltan®) for drinking water, White FDA EPDM70 (Keltan®).