What's a 'drag link'

[Lanciaman]

If you have a real struggle breaking a ball joint heat from a blow-lamp usually does it, but there may be collateral damage depending on how big your burner is. If you have oxy-acetylene (and that's not many of us) you get a much hotter focused flame. But my calor gas blow lamp is good enough for most jobs, and sounds like a jet engine for added fun
Top tip: wear gloves.

I've got a set of bottles but these are now very illegal so I won't mention that.