Though flat washers come in different types, including stone and wooden ones, the best one for commercial purpose is that which is made using stainless steel. Most commercial devices and appliances are run for several years. So, there is a clear need for something which will not give in easily. It is quite likely that the machine will be under immense mechanical pressure and may have to deal with very heavy loads. In such a scenario, the washer may develop crack or give in totally if it is made of a weaker material.
So, only stainless steel flat washers are recommended for any commercial activity. Most firms and factories use only the stainless steel flat washers by Shanes Stainless Store which are not just hard and durable but are also immune to rust and corrosion.