1.Create  simple line like this below.

2) Than select these vartex.

3) Right click on one of them, and select smooth option.

4) When that is done chose Lathe from modifier list and check Flip Normals and Weld Core, set segments to 40.

5) To ease your job assign simple material to head of the light ball and reduce opacity amount to 50.

6) After that assign shell modifier from modifier list and set Outer Amount what ever you like, it must be small value because glass of  the light ball is very tick.

7) To create bolt, draw again basic shape like this below.

8) Repeat 2-4 step and you will get something like this

9) To create detail on the bolt draw line like this below

10) Before assigning Lathe modifier you must change pivot position.

You will do that by clicking on Affect Pivot Only in Hierarchy panel.

11) Right click on Transform Type in, set x to 0.

This will move pivot to centar of the future object.

Click on Affect Pivot Only to close it.