Abstract: A hammer bank assembly useful in high speed, moving type, impact printers of the kind generally employed in data processing systems. The assembly is comprised of a mounting structure supporting a plurality of aligned hammer modules and a plurality of aligned magnet modules. The mounting structure includes a rigid cylindrical tube and a plurality of fastening members disposed therealong. Each hammer module includes multiple hammers resiliently mounted on a common foot member. Each hammer is comprised of an impact tip carried on a rigid coil structure. Each hammer module foot member has a recess of substantially semicircular cross section dimensioned to conform to the periphery of the rigid tube. A plurality of identical hammer modules are mounted on the rigid tube with each foot member being secured to a different fastening member and with the tube engaging each foot member in the recess thereof.