Phone: (973) 827-7155 |Email: sales@accform.com

Custom Manufacturer of Deep Drawn
Metal Parts, Components and Products

The Decisions Behind the Apple Watch Manufacturing Process

Posted by Rachel Daugherty on May 26, 2015 11:12:26 AM

The sophisticated manufacturing process used in the creation of the new Apple watch combines technology with engineering to produce a product that is as beautiful to look at as it is complicated to construct.

Apple_Watch_-_2015_May_26

For the body of the watch Apple selected gold, stainless steel, and aluminum as the materials of choice. As each of these materials has very unique properties, the manufacturing process required to produce quality parts needed to be carefully identified and applied.

Gold Casing

Gold is used extensively in the jewelry and watch industry, but is actually a very poor choice for such applications as it is malleable, soft, and damages easily. Apple has addressed this issue by custom engineering a gold alloy that provides the color and depth desired while adding strength.

To further increase durability, Apple utilizes a process known as work hardening in which the blanks are processed in a roll press and subjected to extreme force in small increments, precisely altering the material grain structure until the desired properties are attained. The combination of these methods results in a material that is significantly harder than original while maintaining the beauty of pure gold.

Stainless Steel Casing

In stark contrast to gold, stainless steel is a robust, extremely hard material that requires a considerably different manufacturing process. The Apple watch uses a type of 316L grade stainless steel which is formed into sticks through a crucible forge process with each blank then cut from the shaped stick.

To form the blank to the desired shape while maintaining material strength, Apple applies a manufacturing process known as cold forging. The cold-forge process forces the material into shape under extreme pressure, thus creating a final design that has an intact grain lattice that flows with the shape of the part. This process is generally considered the most desirable for creating parts with high strength and durability.

Using a five-axis CNC mill, the rough blank is formed into final shape and then sent for finishing with a Tungsten DLC (Diamond-Like Carbon) process.

Aluminum Casing

For the aluminum watches, Apple employs an extrusion process to create the form, which is then machined using precision milling and laser equipment. Apple uses a proprietary laser process to remove machining burrs from all edges and surfaces, including those inside the casing. Once complete, each blank is then bead blasted to produce a high polished finish.

Finishings

For each type of material casing, Apple uses a high precision Coordinate Measuring Machine (CMM) in the final inspection process and then sends the part for polishing using customized tool holding equipment and buffing wheels.

Typical polishing processes can be detrimental to softer material products as the buffing wheel is capable of rounding edges and changing contours in an uncontrolled manner. By crafting a unique tool holder that covers critical design features, the Apple process is able to preserve the clean edges where desired while reducing wear on the buffing wheel. Once final polishing is complete, each part is sent back to the CMM for inspection once more before being considered a finished part.

The watch is then assembled with a variety of different bands and the internal electronics are installed. The housing is then sealed using a crystal forged from a type of ceramic called zirconia, which is non-conductive and therefore does not interfere with antenna operation. The new watch is now sealed, strapped, and ready for shipment.

The Apple watch manufacturing process is an excellent example of the innovations that technology provides. Through combination of existing methods and a bit of esoteric engineering, the impossible becomes more possible every day.

All videos courtesy of Apple image courtesy of Martin Hajek*

deep drawn vs screw machining decision guide

Tags: manufacturing industry