Spark Plug Thread Repair Kit 25 Piece (M14 X 1.25) in Metal Case

As others have said. The inserts are a bit too big to go cleanly into the threads the tap cuts. You can with force it in on an aluminium head, but on a cast one not a chance. The insert is holding so although it's a very tight fit, if you do get it in, I don't think the insert is going anywhere.It's hard to know whether to recommend it or not, given its questionable quality but a time-sert kit is 4 times the price of this, so for the price I'd give it a hesitant recommendation as long as you know what you're getting yourself in for.

A good piece of kit I thought initially. Re-tapping the hole was child's play and took 10 mins.Unfortunately, the whole process is let down by the poor quality of the inserts as they are (in my batch anyway) manufactured oversize and would not go into the re-tapped hole. I'm a toolmaker by trade and have a lathe in my garage which I used to chase the thread to reduce its size.Without the use of my lathe I would have had to try and source some other higher quality inserts. Not the easiest of tasks on a Friday evening.Nielsen need to batch inspect components to ensure they are actually fit for purpose, otherwise it lets down what is essentially a good product.

This looks a good kit, and all went well until it came to screwing in the insert. They are too big to go in. You can just about screw one into a soft aluminium cylinder head, but there is no way will they screw into a cylinder head made of cast iron. A replacement kit that was sent was no better. A review of this product from 5 years ago highlighted the same problem, so it would appear that there is no quality control.

Good product. Straightforward.

Did what I expected

Quick fix and Car now sold on

Excellent very handy kit