Sometimes having your knives made sharp can be a disadvantage. At least that's what blade maker Heng Qitong thinks about knives and swords that are used in battle. Heng believes that having a blunt edge encourages a strong thrust.

"If a knife maker burnishes the edges into sharp ones, the knife doesn't have virtue anymore," said Heng, the eighth generation of Knife Heng, a celebrated family famous for making knives for the royal court in Qing Dynasty (1644-1911). Heng explained that different from knives for cutting meats and vegetables in the kitchen, knives made for fighting against enemies in the field should be blunt and only the tip should be made sharp.

Knife maker Heng Qitong wields his knives.

He took a knife from a shelf at the corner of his home near the Dongdan area, and touched the edge. "You see, my hand doesn't hurt," he said. Ancient Chinese warriors didn't use knives to cut but to focus their strength on the sharp tip. They used their kungfu power can make full use of the weight of knives and enhance their killing strength.

Born in a family of knife-makers, 44-year-old Heng formally started the business at 30. Before that, he studied for a bachelor's degree of Chinese culture, and was taught the history of Chinese knives and swords by his father and grandfather at home.

He began to learn the unique techniques of making knives and swords under his father after graduation. "Our family choose a kind of "elastic steel" for the head of knifes and swords and cast them with hands," Zheng said, showing a shining sword. "It should be pounded by hand at least 18,000 times." After pounding, the steel becomes so elastic that the sword can be bent around the waist without breaking.

On the shelf of his home, various knives made by Heng's ancestors reveal the prosperous history of his family business. According to Heng, in the early Qing Dynasty (1644-1911), the Manchu family only made knives for the royal court. Their family was given the surname "Heng" by Emperor Kangxi in 1672.

For hundreds of years, the Knife Heng's products have gained a reputation for their fine materials, unique construction and traditional style.

All of Heng's products have his name carved on the back, to show modesty and respect to the warriors who use it. "Knives were used by high-ranking warriors, while swords are used by common people," he said.

During his research, the Hengs discovered a casting technique combining stainless steel with a manganese alloy, which prevented knives and swords from rusting. The heads of the knives and swords are dipped with a kind of bean oil, so that they are tough yet flexible.

One of Heng's masterpieces is a knife called Feilong (flying dragon), which took him three years to finish. Heng spread his hand to show the scar left from making the knife. "To control the temperature during the forging, I need to use the back of my hand to touch the knife when it is heated, as that part of the hand is much more sensitive," he said.

To ensure top quality, Heng only makes knives in the best weather, and while he is in a good mood.

"In rainy days, the knives might be bad if they take in humidity when getting made; in windy days, the fire might be affected; while in days when I am in a bad mood, I might not make a perfect knife," said Heng.

Heng also makes sheaths for his blades, which are carved with traditional patterns and decorated with cloisonn and shells. It takes him about three months to make a knife, each costing 3,000 yuan.

The knives made by Heng have gained numerous domestic and international awards. His products have been highly praised and treasured by statesmen from China and abroad, as well as celebrities from different walks of life. They are also regarded as high-end gifts to guests and preserved in museums overseas.