JLG Parts Socket Head Cap Screw is used on various JLG Boom and Scissor MEWP(Mobile Elevated Work Platform) Machines. This cap screw is primarily used to hold the fan to the fan spacer on JLG Boom Machines with a Deutz 2.9 engine installed. It is also used to hold the handle to the platform on the RT and CM Series Scissor Machines. It has a 5/16"-18 thread pitch at a .75(3/4") length. Model Use: Ultra Series , 400 Series, 500 Series, 600 Series, 700 Series, 800 Series Boom Machines as well as the RT and CM Series Scissors. Please ensure proper model and serial break before parts purchase.