Very few Stratocasters were built with hard tails, but some guitarists prefer them. Eric Clapton, for instance. If your Strat has a tremolo tailpiece, and you want a hard tail, you can do what Eric did and block the tremolo (which is actually a vibrato, but after decades, the name stuck). Naturally, we recommend letting a qualified guitar tech do this (particularly if your Strat is still under warranty), but if you’re a “hands-on” type person, here’s how to do it. First, lower the bridge posts and tighter the spring claw until the bridge sits level with the top of the guitar (you may want to add the extra spring(s) if your Strat came with one or more missing – Strats usually come with only three out of five possible springs). Then carefully cut a hardwood block that fits inside the cavity behind the existing tremolo. Hint: Use a hard wood like maple rather than a soft wood like pine, and make sure you have a snug fit. Once you’ve inserted the block, and string tension is brought back up to normal, you should have, in effect, a hard-tail Strat. All that’s left is to replace the plastic cover that normally conceals the tremolo parts and you’re ready to rock!
Don’t want to deal with wood blocks? An easier but very effective method for blocking your tremolo is to tighten the two spring claw plate screws until they are flush against the body (make sure you detune before you do this) Then, make sure that you have all five springs attached to your spring claw and tremolo block. The tension exerted from the five springs will be more than enough to keep your bridge flush to the body. This method has been proven to work even with extremely heavy string gauges such as Stevie Ray Vaughan’s setup (.013 – .056) in standard tuning pitch.