https://www.aqemachinery.com/product-die-collar.html Die Collar Die Collars are simple, ...    More ...

https://www.aqemachinery.com/product-die-collar.html          
 
Die Collar
Die Collars are simple, rugged, reliable external catch fishing tools that tap on the outside wall of tubing objects such as tubing and drill pipes. The die collar has a long cylindrical integral structure which consists of the body with threads on the internal wall and a lipped guide. The threaded die collar is made of high-strength alloy and is made with a cutting groove of fishing threads.     
 
Description
Die Collar is a special external fishing tool which is engaged on the outside wall of tubing objects such as oil tubing and drill pipe. They are made with chip groove so as to make threads easily. The Taper Taps and Die Collar are made up of high quality alloy steel and processed by special heat treatment, having the advantages of high strength, high toughness and easy tapping.     

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