Welding symbol is quite common and should be there in the Base platform too.

I have loaded the detweld.dll /ma files from the mdl application. its giving this error. "OS could not load C:\Configuration\ConfigurationSets\Hatch\Hatch_Common\mdlapps\detweld.dll, error 126.

MDL Loader: Unable to load library (DLL or MDL shared library) detweld"

I am using MicroStation version 10.16.03.11 and testing is pure under local environment. I have copied the dll/ma file from the OpenBuildings Designer

Link to community - https://communities.bentley.com/products/microstation/f/microstation-forum/243719/how-to-add-the-welding-symbol-from-obd-annotation-to-microstation