When people talking about the hollow metal double doors, the first reaction/impression should be two pieces equal size doors. Actually there is a kind of double doors named unequal double door, it also called mother and son doors. It is a special design with one narrower door leaf and one wider door leaf.
When the width of the door opening is large, the door leaf is designed as a large and a small child-door form for the overall beauty of the door. When the door width needs to be designed, it is larger than the width of the ordinary single door (800 ~ 1000mm), but smaller than the double door. When the total width of the door (2000 ~ 4000mm), the child-mother door can be used.
The specification of the mother and son hollow metal double door is as following:
1. Available in galvanized steel.
2. Each door has a ul label, and the fire rated time can be 20/60/90/180minutes.
3. Common hardware can be equipped.
4. Full welded edges, KD frame or welded frame as option
The advantage of unequal double doors.
1. Just push the smaller door when opening and closing, when half of the double doors are too small to pass or need to pass through large objects such as furniture, they can all be opened. the door and open two leafs when
2. Many entrance doors are relatively large in size, so it is not beautiful and practical to make a single door, mother and son door is a better choice.