I chopped through 1/3 of the width of the cord leading to my angle grinder - it still works should I replace the cord?
Yes, replace the cord.
Seen too many damaged cords covered in unravelling sticky tape that then become dangerous - wet environment, spilled liquid etc etc
Adding a cable joiner just adds a &quot;catching&quot; or &quot;trapping&quot; hazard.
2 or 3 metres (6 or 9 feet for some) of quality cable is cheap and safer.
Also the length of cable is likely to be cheaper than a fancy repair plug...