Review on 🔩 E-Z LOK 851618-20 Threaded Insert, Zinc, Hex-Flush, 5/16"-18 Internal Threads, 0.789" Length - Pack of 50 units by Eric Garron

I don't know what problems some people have. Drill a 9mm diameter pilot hole and install in the wood using a 6mm allen key or screwdriver NOT INCLUDED. (I'd rather pay a few bucks more and have it boxed up and then after realizing the second photo is just a link.) It literally is. Use the high speed, low torque setting on the drill and increase the torque if it slips too quickly. Learn how to use a drilling/drilling machine. You MUST drill a pilot hole. It should be very close to 9mm. These things have good holding power and they all fit very well. I recommend it.