1. All our products accord with API SPEC 7 standard, and we get the right to use the API 7 LOGO.
2. The heat treatment technique is conducted within the range of full length of products.
3. The bottom of thread of Spiral drill collars can be processed with cold roller according to the customers' requirements.
4. All of the threads are treated with phosphorization and copper plating.
5. The rolled or forged AISI 4145H chrome molybdenum steel is used, which can keep effective control to the chemical compositions and microelements.