JLG Parts Flat Hex Head Countersunk Bolt for use on JLG Boom and Scissor MEWP(Mobile Elevated Work Platform) Machines. This bolt is used to hold the Planetary Ring Gear Assembly to the Torque Hub Housing. It has a 3/8"-16 Thread Pitch. Model Use: 300 Series, 400 Series, 500 Series, 600 Series Boom Machines as well as LE and RT Scissor Machine. Please ensure proper model and serial range before parts purchase.