A well worn and treasured Rolex Oyster Perpetual ref. 6074 is brought back to life by Henrik Korpela, principal of independent Swiss watchmaking school KHWCC. Korpela himself explains the process of restoring the family heirloom, all the while maintaining its character, in enlightening detail.
Steel screws used in watch movements are often blue. Traditionally this is done by heating the screws, hardening them and also giving them an attractive blue colour, a process Henrik Korpela explains in this in-depth article.
Black polishing, also known as spéculaire finishing, is employed to finish steel parts in a watch movement to create a mirror-like surface. Used for steel screws, levers and bridges, true black polishing is done by hand and only found in the best timepieces. Henrik Korpela explains the technique here.