User blog comment:SpaceManiac888/Rusty Spanner of the Episode: Series 10, Heat 5/@comment-1770349-20171126215949/@comment-29001736-20171127105438

I don’t believe Shunt’s axe head is welded on, it appears to be connected to the main shaft by two metal plates and some bolts, I think you can see the bolt holes in the axe head when it comes off.