Nickel Plated Electric Strings wound on Round Cores. Tite-Fit nickel plated electric guitar strings are designed to be a great all-around string. Based on a round core, the construction techniques for the Tite-Fits are very old. However, the core wire and wrap wire in DRs are the latest, most advanced and expensive metals available. For flexibility, for tone, for long life: for Rock, Blues, Metal and Jazz. Tite-Fits are a wonderful all purpose string. Our most popular electric guitar set.