In this period the cursor was branded with BDM acromyn of the names of those who were mainly involved in the development years:
Bercovitz – owner of the english engineering society
Doleter – machine developer
Mulka – zipper developer and license owner
The first model was “light duty 10” with 10 teethe for zipper inch (1953)
This has been followed by “duty 8 Medium” with 8 teeth per inch, on request of the UK Defense department (1956)
The first usage was for the storage of moisture-sensitive equipment, but soon it was used for drysuits.
In 1958 NASA commissioned the manufacture of a zip with 6 teeth per inch, for Mercury and Gemini programs and later the BDM zipper went to the moon with the Apollo spacecraft.
The BDM zipper remains the fisrt choice in the field of waterproof zippers, where it is necessary a high sealing pressure, and when the life risk is high. Health and safety laws in fact leave no room for mistakes in the design of protective suits in the modern world!
Military forces, the Navy, Special Forces and the Fire Department from all around the world have chosen to use the BDM.
BDM zipper, has the same characteristics of the Dynat, but with a higher price, because it is more easily applicable and does not need lubrication.
The BDM is measured latches included.
To find thewhole chain measure subtract about 4/5 cm.
If you need to know the actual opening hole, subtract about 5 cm from the measuring chain.