Stainless steel frame
crafted in a 40-step process
Mi 4 is not just a leading-edge smartphone, it's a work of art. A forged stainless steel frame and
aluminum-magnesium alloy mid-frame combine to make an exceptionally sturdy structure, while the
ultra-thin screen and beautifully textured back cover make Mi 4 a joy to hold. The next-generation Mi phone
is truly the perfect blend of style and substance.
Turning steel into art
The frame of each Mi 4 handset is the result of 193 carefully designed high-precision
manufacturing processes. Using advanced engineering techniques and a keen artistic sense, we
transform 309 grams of raw steel into a 19-gram masterpiece over the course of 32 hours of
processing, crafting, and polishing.
Probably the most sophisticated manufacturing
process for any smartphone, ever.
The Mi 4 frame alone requires 193 separate manufacturing processes to produce. The major
steps include forging, molding, eight stages of CNC milling, micron sandblasting, and PVD and
nano-grade Anti-Fingerprint (AF) coating. No fewer than 342 technicians work
on each phone, to ensure every last detail is technically and aesthetically perfect.
The world's first 9-layer IMT back cover
with 0.06mm grain
Made up of 9 layered membranes, the back cover is just 0.8mm and features a grating
pattern, made up of intricate lines just 0.06mm thin. This has a beautiful tactile feel, and a subtle
visual effect that changes when you look at it from different angles. The multi-layered
membrane construction is scratch and fingerprint-resistant. The only way to combine so many
thin layers together was by using In Mold Transfer (IMT) technology – the first time this
technique has been used in a mobile phone cover.
Enhanced with an aluminum-magnesium alloy
Strength and lightness don't always go together. So we put serious engineering thought into creating a body
structure that balances these 2 attributes. Our solution? A lightweight and stable aluminum-magnesium
mid-frame protected by a more robust stainless steel outer. An edge-protecting membrane inserted between the
screen and the external frame absorbs shocks and reinforces the four corners of the phone, and a conductive
graphite thermal film improves cooling by rapidly dissipating heat.
Aluminum-magnesium alloy mid-frame
The magnesium alloy contains two-thirds
aluminum and one quarter steel.
It is the lightest usable alloy that has
sufficient physical strength.
Reinforced drop-resistant corners
The reinforced edges are designed not to
deform easily if the phone is dropped,
reducing the chances of screen damage.
Edge Coating for extra protection
A 0.05mm-thick Edge Coating layer under
the screen glass acts as a shock absorber,
reducing the energy transmitted from the
frame to the glass in the event of an impact.
Elegance comes from attention to detail
Every component of Mi 4's body has a minimalist elegance about it. The headphone jack and the
infrared emitter sit in the middle of the phone's top edge. Two metal buttons and the micro-SIM slot
are incorporated into the side edges. A micro-USB port and speaker holes are found in the bottom
edge. Each of the 45 speaker holes is CNC-milled to a diameter of precisely 0.6mm.
Please note that Mi 4 uses a micro-SIM card.
The display measures 5 inches diagonally, and the
body is just 6.85cm wide. The frame is made entirely
of metal, yet the whole phone weighs just 149g.
With its ultra-thin display, perfectly balanced body,
smooth sandblasted finish, and back edges curved to
fit the palm, Mi 4 sits perfectly in your hand.
A beautiful protective flip cover is available for Mi 4, made of smooth faux leather
and lined with microfiber to protect the screen against scratching.It comes in 5
elegant colors: sky blue, red, green, white, and black.
A protective cover in genuine cowhide leather is also available as an accessory,
in a range of stylish retro colors.
Open to activate,
close to protect
Close the flip cover, and Mi 4 goes into sleep mode.
Flip it open, and Mi 4 automatically wakes up.
This cover provides comprehensive protection
and is the perfect fit. Holes for the camera and
microphone ensure it won't compromise Mi 4
functionality in any way.