For permanent maintenance.

To make watches that will be treasured for more than 100 years … our goal is to make watches that can still be used even after 100 years. The MORE* structure adopted in the Master Craft Series reflects this philosophy. The MORE structure, which is inspired by Japanese traditional wooden puzzles, allows all external parts to be assembled and disassembled like a wooden puzzle. Therefore, every part can be replaced individually, which prolongs product life and facilitates maintenance.
For instance, a bracelet is generally completed by assembling segments and then pressing them from both sides. Such bracelets are robust, but cannot be disassembled in case of damage. In contrast, the Master Craft Series bracelets can be completely disassembled, and so it is possible to repair or replace only the damaged parts. The MORE structure is also used in the DIVIDO, a new work of the HiZ Series.
In general, disassemblable bracelets tend to become longer with use, and so other manufacturers prefer not to use such bracelets. Disassemblable bracelets are no longer used even for ultrahigh-quality watches. However, we succeeded in creating bracelets having appropriate play and high durability by taking advantage of our expertise in precision machining and assembly. This was made possible by our expertise in precision machining as well as our highly skilled craftsmen.
* MORE stands for Minase Original Rebuilding Equation. MINASE patented the MORE structure for wrist watches (Pat. No. 4671327) and for watch bands (Pat. No. 4674698).
The segments of MINASE’s bracelets are cut by hand one by one by craftsmen. The reason we do this, even though bracelet segments are usually cut by CNC machining, is to keep the lateral play of segments within 2/100 mm. It is difficult to fine-tune this amount of play by CNC machining, which inevitably results in inflexible bracelets. We have added a delicate touch to the robust Master Craft Series bracelets by this strict precision control.
After being assembled, the segments are fastened with screws one by one. Normally, segments are screwed from both sides. This is advantageous for productivity, but the screws may come off after prolonged use. Accordingly, the segments of the Master Series bracelets are designed to be fastened with MINASE’s original screws from the back side. As the screws are hidden from the outside, the bracelets look neat and do not fall apart even when the screws come loose. In addition, each screw is fixed by applying a fixing agent. This is a time-consuming process that is not suitable for mass-production manufacturers.
The play in a bracelet hole is 5/100 mm. This relatively large play is intended to prevent the generation of metal powder due to abrasion between a pipe and the bracelet. However, it results in a large play of the bracelet. Therefore, the clearance between the right and left segments is minimized in order to ensure durability.