which can only be opened with the provided key

and flush pin-hex security screws

This sheet metal is extra thick

5-15/64" centrifugal fan with multiple metallic vanes

Nidec US Motors H50V3B Inverter Hostile Duty Motor, 50 HP, 3-Phase, 2400-1200 RPM, 230, 460V, 365T Frame Nominal Size-24" X 1.25" which can only be openedFeatures: 40 C ambient, 10: 1 speed range with variable torque, 5: 1 with constant torque Item: Hazardous Location Motor, Motor Type: 3 Phase, HP: 50, Nameplate RPM: 2400 1200, Voltage: 230 460, Frame: 365T, Enclosure: Totally Enclosed, Rotation: CW CCW, Hz: 60, Phase: 3, Service Factor: 1. 15, Insulation Class: F, Bearings: Ball, Base: Rigid, Shaft Type: Key, Shaft Number: 1, Shaft Length: 6. 13", Shaft Height: 9", Shaft Dia.: 2. 375", "C" Dim: 32.