There is a type of Chinese numismatic charm with the inscription Qianlong Tongbao which might have been cast during the reign of the Qianlong Emperor which is 56 millimeters in diameter and has a thickness of just slightly more than 3 millimeters.
The Chinese characters of this amulet are also different style from those of circulating Qianlong Tongbao cash coins, such as the bottom part of the "Bao" (寶) and the radical portion of the "Tong" (通).
The Manchu characters on the reverse side of this amulet indicate that it was manufactured at the Ministry of Revenue Mint in Beijing.
However, these Manchu characters appear to be very large compared to other Manchu mint marks and are rotated 90 degrees clockwise.
The intention of this may have had political motivations but the meaning of why this was done remains unclear today.

Another method how Qianlong Tongbao cash coins are used as charms is by stringing them together in the shape of a sword, these amulets are referred to as "Chinese coin swords", these Chinese coin swords consist of either one or two iron rods which are used as their foundation and the Qianlong Tongbao coins (but sometimes other inscriptions may also be used) are fastened with a red string, cord, or wire.
A Chinese coin sword is usually about 60 centimeter long and typically consists of around one hundred bronze Chinese cash coins.
One of these Chinese coin swords made with Qianlong Tongbao cash coins is in the collection of the British Museum.
There is a type of Chinese numismatic charm with the inscription Qianlong Tongbao which might have been cast during the reign of the Qianlong Emperor which is 56 millimeters in diameter and has a thickness of just slightly more than 3 millimeters. The Chinese characters of this amulet are also different style from those of circulating Qianlong Tongbao cash coins, such as the bottom part of the "Bao" (寶) and the radical portion of the "Tong" (通). The Manchu characters on the reverse side of this amulet indicate that it was manufactured at the Ministry of Revenue Mint in Beijing. However, these Manchu characters appear to be very large compared to other Manchu mint marks and are rotated 90 degrees clockwise. The intention of this may have had political motivations but the meaning of why this was done remains unclear today. 
Another method how Qianlong Tongbao cash coins are used as charms is by stringing them together in the shape of a sword, these amulets are referred to as "Chinese coin swords", these Chinese coin swords consist of either one or two iron rods which are used as their foundation and the Qianlong Tongbao coins (but sometimes other inscriptions may also be used) are fastened with a red string, cord, or wire. A Chinese coin sword is usually about 60 centimeter long and typically consists of around one hundred bronze Chinese cash coins. One of these Chinese coin swords made with Qianlong Tongbao cash coins is in the collection of the British Museum.
Qianlong Tongbao