Lockwood Mortice Universal Flush Bolt Ferrule The Lockwood Mortice Universal Flush Bolt Ferrule can be used in conjunction with flush bolts to secure the fixed leaf panel of a double door. The spring loaded dust cover minimises dust and dirt build up in the flush bolt hole. Specification Dimensions13mm diameter spring loaded dust cover25mm diameter top19mm diameter base40mm height Available in the following finish Satin Stainless Steel (SS) Close Part numbers Trade Pack Description Part Number Mortice Universal Flush Bolt Ferrule 8402SS Close Where to buy? Find your local Lockwood stockist. Lockwood Flush BoltsFlush mounted bolt. Lockwood 680 Patio BoltSurface mounted heavy duty bolt. Lockwood Barrel BoltsA series of barrel bolts to suit a variety of applications.