A shoe sole of Mao Lasheng is rubbed thinner than other parts due to long-term use. [Photo/CCTV]

In 2006, the factory Mao worked at was tasked with making the outer part for a key type of guided missile in the country. While the lab test fared well, the practical trial failed more than 20 times because of cracks in the mold. Despite many rounds of analysis by experts, they could not find the flaw.

It was then that Mao Lasheng was tasked with finding out the problem.

Mao moved into the laboratory, bringing food with him, amid many doubtful voices. After two days of experiments, and repeated trial-and-error, Mao finally walked out the lab with bloodshot eyes to the people waiting outside to find out how the problem was solved.

"It is truly amazing. The problem that puzzled senior engineers was solved by a blue collar worker," said Yu Kaisheng from the science and technology committee of the factory.

It was the fourth time that a product Mao Lasheng made was displayed in Tian'anmen Square when the HQ-12 air-defense missile was paraded in the Victory Day military parade held in Beijing on Sept 3 last year.

Mao Lasheng (middle) works on a sand mold with his colleagues. [Photo/CCTV]

With the development of new military equipment, Mao feels more pressure. "The new material should be lighter, with higher strength and heat resistance. I could not sleep for nights when I could not overcome a technical problem," said Mao.

To keep up with new developments, Mao immerses himself in books when he has spare time.

Mao is an introverted man who is not good at communicating, even with his family. "As far as the job is concerned, it's okay for me to talk with people. But when it comes to matters in life, I am not good at it," he said.

With his parents having passed away years ago, his daughter working away from home, and most of his acquaintances in the workshop having retired, Mao talked even less in recent years.

"Sometimes I go to the workshop and play with the sand by making them into different shapes," said Mao. "Sand is just like children, it does what I tell it to."