A-AXE35145-AI Knifehead; SickleOne New Aftermarket Replacement Sickle Knifehead Fits John Deere Grain Headers This aftermarket replacement sickle knifehead Fits John Deere 600 Series grain headers and draper headers. The knifehead is the drive component at the end of the sickle bar that connects to the pitman arm, converting rotary motion into the reciprocating cutting action of the sickle assembly. Keeping this component in good working order is essential for clean, efficient