Making a splash in water-resistant digital devices: Page 3 of 4

November 24, 2016 //By Sean Riskin
The trend in consumer electronics has always been to make them faster, smarter, and with ever-expanding capabilities. But waterproofing has become the new focus of global electronics manufacturers and most brands are rushing to include this benefit to ensure they are not left behind in this ultra-competitive market. Since water-resistant standards play a big role in making expensive handheld and wearable digital devices more durable, the industry has adopted the IPX7 rating, which protects against immersion in water for 30 minutes at a depth of 1 meter (3.28 feet).

The solution Riskin was looking for came from the combination of under head design features of screws and Spiralock, a subsidiary of Stanley, which years ago developed and re-engineered a female thread profile that adds a unique 30-degree wedge ramp at the root of the thread and mates with standard 60-degree male thread fasteners. This innovation removes the need for nylon-based patches or other anti-vibration countermeasures and therefore significantly reduces the cost of fasteners.

Riskin’s study revealed other advantages, too. When torqued to specifications, standard screws are not perfectly perpendicular; most are a couple of degrees off-access and therefore provide a gap where fluid can enter.

The Spiralock thread profile, in comparison, is self-centering and the head of the fastener is perpendicular to the bearing surface. Riskin knew that this alone would not entirely seal out moisture, so he added an 87-degree under head feature and semi-flat head to the micro fasteners. Although the head designs have been available for years, this is the first time they’ve been combined with Spiralock’s modified locking thread profile to create excellent moisture sealing joints that exceeds the IXP7 rating standards.


The 87-degree under head feature.

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