Cap Screw, M4x16, Socket Head 

In your instruction manual, this part appears on the parts list as:

Item No	Models
100	BusyBee CX611 Craftex Small Mill Grizzly G0619 Grizzly Small Mill Various SX3 SIEG Small Mill Travers Tools OT2225SX3 OTMT Small Mill
116	Grizzly G0463 Grizzly Small Mill Harbor Freight 93885 Central Machinery Small Mill Various X3-US SIEG Small Mill Woodstock International M1110 Shop Fox Small Mill
67	LittleMachineShop.com 3536 HiTorque Bench Lathe - 8.5x16 LittleMachineShop.com 3540 HiTorque Bench Lathe - 8.5x20 LittleMachineShop.com 3595 HiTorque Bench Lathe - 8.5x20 Various SC4-US SIEG Bench Lathe Travers Tools OT218410 OTMT Bench Lathe - 8.5x16 LittleMachineShop.com 7550 HiTorque Bench Lathe - 8.5x20 LittleMachineShop.com 7500 HiTorque Bench Lathe - 8.5x20
C16	LittleMachineShop.com 5550 HiTorque Bench Mill Various SX2.7L-US SIEG Bench Mill LittleMachineShop.com 6550 HiTorque Bench Mill LittleMachineShop.com 6570 HiTorque Bench Mill
C30	LittleMachineShop.com 6700 HiTorque Large Bench Mill LittleMachineShop.com 6750 HiTorque Large Bench Mill Various SX3.5-US SIEG Large Bench Mill LittleMachineShop.com 6770 HiTorque Large Bench Mill
C31	LittleMachineShop.com 5500 HiTorque Bench Mill Various SX2.7-US SIEG Bench Mill LittleMachineShop.com 5520 HiTorque Bench Mill LittleMachineShop.com 6500 HiTorque Bench Mill
D11	LittleMachineShop.com 5500 HiTorque Bench Mill LittleMachineShop.com 5550 HiTorque Bench Mill
D22	LittleMachineShop.com 6500 HiTorque Bench Mill LittleMachineShop.com 6550 HiTorque Bench Mill LittleMachineShop.com 6570 HiTorque Bench Mill

Click your model to see the complete parts list.