SF-2 material is a three-layer composite self-lubricating material made of polytetrafluoroethylene modified polyoxymethylene plastic as the surface layer. It is a benign boundary lubricating material, making it particularly suitable for bearings, thrust pads, sliders, ball seats, and other friction parts that are not easily lubricated by fluid dynamics due to high load and low-speed rotational motion, swinging motion, and frequent opening and closing under load. SF-2 can fully utilize trace amounts of lubricating grease and can be maintained for a long time without refueling under boundary lubrication conditions. Under completely oil-free lubrication conditions, the friction performance and allowable PV value of SF-2 are relatively low, so oil storage pits are usually rolled out on the plastic surface and lithium based lubricating grease or silicone grease is applied during assembly.