API 7-1 Standard cross-over sub and x-over sub

API 7-1 Standard cross-over sub and x-over sub 1. Standard;API 2. Type: for connect the drill stems

API standard drilling cross-over sub1. Standard;API 2. Type: for connect the drill stems

Cross-over sub acts for conversion and connection of drill stem component in petroleum ,natural gas and geology drilling work.It is used mainly for connecting of upper drill tools and lower drill tools during drilling operations.

API standard drilling cross-over subIt is a component(sub) used for joint between both drill stem

String Cross-Over Sub

Divided into seven Types by Application
sort	name	top connection	bottom connection	type
1	Kelley saver sub	kelly	drill pipe	A or B
2	Tool joint	drill pipe	drill pipe	A or B
3	Crossover sub	drill pipe	drill collar	A or B
4	Dril colar sub	drill collar	drill collar	A or B
5	Bit sub	drill collar	bit	A or B
6	Swivel sub	swivel bottom sub	kelly	C
7	Junk sub	kelly	drill pipe	C
		drill pipe	fishing tool	C

API 7-1 Standard cross-over sub and x-over sub