If you are having a problem with machine screws on your guitar or amp coming loose you can use Loctite to prevent this. This is helpful on small screws like the ones used for guitar bridge height adjustment. This also works well for the mounting screws on amp handles that come loose occasionally. I like to use just a very small amount of the Loctite Threadlocker Green for the smaller screws on guitars as well as some of the larger amp screws. Only use a very small amount just enough to prevent the screws from coming loose. You do not want to use too much making it difficult in case you want to remove or adjust the screws. You will find many uses for this product. Loctite Threadlocker is available at any hardware store or an Home Depot or Lowe’s. A little dab will do ya!