Kelly is the drive part of whole drill string, it transmit the torsional energy from the rotary table to the bit in the bottom of the hole. Siquan precision-machined Kelly is a heavy square or hexagonal steel bar supported by the swivel through the rotary table and connected to the first joint of drill pipe in the drill string.Straightness is the key manufacturing process. Straightness is checked before, during and after each machining operation. Flats are precision-milled to API and NS-1 specifications. All milling is performed on specially designed rigid Kelly mills. Each Kelly is furnished with a pressed steel thread protectors.

Features and Benefits

● Manufactured from AISI 4145H-modified, fully heat-treated alloy steel with a Brinell hardness range of 285-341 and a minimum average Charpy impact value of 40 ft-lbs.

● Ends and drive sections, IDs and connections machined and inspected to API and NS-1 specifications.

● Kelly bars ultrasonically inspected over full length and section.

● Shipped in a protective steel-cased scabbard.
When ordering Please specify:

● Kelly type (square or hexagonal).

● Nominal size and overall length.

● Upper and lower Connections.
Specifications - Rotary Kelly:

Nom Size (in)	Top Connection(LH)		Bottom Connection		I.D.(in)		Drive Section(in)
	Standard  O.D.(in)	Optional   O.D.(in)	Square    O.D.(in)	Hex.    O.D.(in)	Square	Hex.	A	B
2 1/2	6 5/8REG    7 3/4	4 1/2REG    5 3/4	NC26     85.7		1 1/4		3 2/7
3	6 5/8REG    7 3/4	4 1/2REG    5 3/4	NC31     4 1/8	NC26    3 3/8	1 3/4	1 1/4	4	3 3/8
3 1/2	6 5/8REG    7 3/4	4 1/2REG    5 3/4	NC38     4 3/4	NC31    4 1/8	2 1/4	1 3/4	4 1/2	4
4 1/4	6 5/8REG    7 3/4	4 1/2REG    5 3/4	NC46     6 1/4	NC38    4 3/4	2 4/5	2 1/4	5 4/7	4 4/5
	6 5/8REG    7 3/4	4 1/2REG    5 3/4	NC50     6 3/8	NC38    4 3/4	2 4/5	2 1/4	5 4/7	4 4/5
5 1/4	6 5/8REG    7 3/4		5 1/2FH      7	NC46    6 1/4	3 1/4	3	7	6
	6 5/8REG    7 3/4		NC56       7	NC50    6 3/8	3 1/4	3 1/4	7	6
6	6 5/8REG    7 3/4			5 1/2FH     7		3 1/2		6 4/5
	6 5/8REG    7 3/4			NC56      7		3 1/2		6 4/5