BEIJING - Robot fingers tap phone screens 1 million times to ensure they don't crack when finally held by humans, one of strict quality control measures by Chinese communications giant Huawei.

The torture chambers are tucked away in a mountainside facility on the northern edge of Beijing, where the world's second-biggest smartphone vendor tests upcoming and current products to challenge Apple's iPhone and Samsung's Galaxy line.

"We are working very hard to net more consumers. It's a very hard job," said Clement Wong, director of product marketing at Huawei's consumer business group.

Despite producing phones at a massive scale, Huawei has not had much-publicized durability issues, unlike exploding batteries on Samsung's recalled Galaxy Note 7 in 2016 and the easily bendable aluminum shell of the Apple iPhone 6 and 6 Plus in 2014.

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In one of the test labs, a plastic material is repeatedly pressed against denim fabric to simulate how being kept inside a tight jeans pocket would affect the phone.

News cameras were not allowed inside the facility for security reasons.

A transparent cylinder with a phone inside does not stop rolling until it simulates the handset being dropped 500 times.

Another machine repeatedly inserts and takes out headphones from a jack at the bottom of the phone. The portion of headphones and chargers that connect to phones are among the most vulnerable to breakage.

In an enclosed chamber, up to 5,000 phones at a time are tested simultaneously by machines to check basic functions such as picture taking, screen tapping, and making calls.

For every smartphone series, at least 10,000 units are tested before they are released commercially, Huawei said.

In June and July, Huawei overtook Apple for the first time to become the world's second-largest smartphone manufacturer by sales, according to industry tracker Counterpoint.

The achievement, however, could be short-lived as Apple unleashes its iPhone X, 8 and 8 Plus in the 4th quarter. But Huawei is not worried, focusing instead on its upcoming releases, including the flagship Mate 10 in October.

Wong said Huawei was working to improve brand awareness.

"Some of the people they've never touched Huawei phone before," he told reporters. "That is the reason why we have fair and right pricing."

Chinese manufacturers like Huawei have undercut Samsung and Apple in terms of price while offering comparable, if not better features.