UMIDIGI: Why and how they made the C Note (video)

by Dimitris Economou 3

UMIDIGI has a philosophy somewhat different from most of other companies. As they state, they believe that every phone deserves a well-built body with premium design and materials. Quality shouldn’t be a privilege of pricey phones. And it seems that they are confident they can achieve what they believe starting with the UMIDIGI C Note.


The all-metal unibody of UMIDIGI C Note is created from a single slab of aerospace-level aluminum, and each one has gone through a 48-hour process of finishing to reach its final form and build quality. Accurate assembling gives the maximum endurance when facing bumps and falls.  UMIDIGI’s founder, Heaven, explains how the metalworking process goes for C Note.


Forging the metal into shape

We picked the aerospace-grade aluminum metal to make UMIDIGI C Note. In order to forge the steel plate into the shape of C Note, Holes are first punched into the body after pressed and cut, to hold the steel plate in place during subsequent processing steps. Then followed by 100-tonne impulse drawing, oil hydraulic press forging, and preliminary outline forging to shape the frame of C Note. Additional measure such as annealing is applied to further indurate the steel.



Completely CNC processed

CNC processing is used on the all-metal body of C Note with each device experiencing 58 milling operations make up by 8-step CNC milling process. In addition, the loudspeaker opening and card slot adopts the four-axis CNC machine tool to perform 360 degree rotational processing and the precision is 0.01mm.



3-step of surface polishing

The surface polishing is an important part. It first comes with 100 seconds of rough polishing, while the milling imprint from the surface of the frame are removed. A wet medium polish with wax then smoothes any residual rough areas. Lastly, a final mirror polish gives the curved recess a slick finish. Chamfer edge is polished with oil ink before sandblasting, frame side is buffed to reduce surface roughness. Compressed air sandblasters are then used to blast the back and sides of the frame until a silky smooth finish is achieved.


Laser cutting frame completion

A highly focused laser beam vaporizes stainless in seconds, separating the frame cleanly from the excessive metal. Skilled technicians then polish the frame to remove all burrs and residues in the cut-off areas.



Edge Coating for screen protection

A 0.05mm-thick layer under the glass with a special Edge Coating acts as a shock absorber if the phone is dropped, reducing the chances of the screen breaking.


A Via Negativa Journey

The company states that the fine art is already there and all they do is remove all the needless parts of a metal slab to reach the final premium shape and quality of UMIDIGI C Note. However, this is a comprehensive fine-tuning metalworking process backed by a perspective vision, and many technical managerial difficulties may lie along the way.

A methodology known as Via Negativa can best describe the process. It is a term originating from the religious practice of approaching or describing Gob by negative terms. Or as simple as sculptor Auguste Rodin has put it: “I choose a block of marble and chop off whatever I don’t need”.

And this, is how UMIDIGI C Note came to life.