A360 VIEWER - Free online CAD Viewer
DWGSee - A lite and fast dwg viewer, let you view, print, markup, measure dwg files. Supports AutoCAD 2020 drawing format!
STP Viewer - Free STP Viewer - free software that lets you view 3D STEP files (.stp, .step file format).
ShareCAD - ShareCAD is one of the powerful tools that offer you a chance to view your 3D model in various formats like DWG, CAD, and many others.
Glovius - Extensible & customizable 3D viewer, for consumption of product design data.
Emb3D 3D Model Viewer - Emb3D 3D Model Viewer is a rich-featured application that lets you create, store, enhance, and show your 3D models in any format you want.