Universal 5 piece Mixed screw & bolt Extractor set

I bought this set to remove some rounded out screws that a drill bit just couldn't bite in anymore and even following the instructions and initially trying to use a spanner rather than a drill, as recommended, the thread on these just disappeared as though it was made of plastic. DO NOT BUY.

I bought what looks like the exact same product elsewhere, and it's very important that you drill a small pilot hole into the head of the damaged screw or bolt before you try to use these. I removed a small screw from the bottom of a cycling shoe which had the head mangled by scraping on tarmac. The smallest of these tools, at slow speed and medium torque brought it out nicely once I'd drilled a 2.5mm pilot hole (I think 2mm is recommended for that one though) just about 1mm deep at most to give it something to bite.

soft steel. bends and twists until snapping. do not recommend

I found these absolutely perfect..... However I did actually know what I was doing!! If you round a screw it will probably because the screw (or bolt) is seized therefore you need to resolve the seizing first. I soaked the area of the screw in WD40 for 24 hours so that it would have time to penatrate and free up the screw. Then I drilled a very clean hole down the centre of the screw as deep as I could. I then drove into the hole the most suitable reverse tool (in my case the middle sized) and one the reverse tool was firmly lodged in the fresh hole the screw then begun to turn and came out in seconds.

To echo previous reviews, the metal was so soft that the thread on the extractor was stripped on the first use. Not only a complete waste of time and money, it has made removing the offending screw even more difficult.