Nylon 6,6 membranes for fluid filtration in the pharmaceutical, biotechnology, electronics, food and beverage industries and for analytical applications. These membranes are very resistant to mechanical, chemical and thermal stress. They can be used in either direction, are inherently hydrophilic, have high flow rates, low pressure drops and very low extractables. Where appropriate, they can be steam sterilised without change in flow or pore size characteristic.