Drill Stem Subs

RK Pipe & Supply supplies a range drilling equipment and supplies including Kelly Saver, Tool Joint, Crossover, Bit, Drill Collar, and Swivel Drilling Subs. Please see our online inventory and contact our sales department for information and quotes.

Drill-stem subs are available in the classes and types shown in Table 1 and Figure 1.

Dimensions For Type-A and Type-B Drilling Subs

Connections, Bevel Diameters and Outside Diameters: The connections, bevel diameters and outside diameters, sizes, styles, dimensions and tolerances listed in the following Tables:

Subs Connecting to Kellys: Tables 1 and 2
Subs Connecting to Tool Joints: Tables 3
Subs Connecting to Drill Collars: Tables 1
Subs Connecting to Bits: Tables 4, 5 and 6

Dimensions For Type-C Drilling Subs

Connections, Bevel Diameters and Outside Diameters: Swivel subs have pin-up and pin-down (both left hand) rotary shouldered connections. The lower connection size, style and bevel diameter DF conforms to the applicable sizes, styles, dimensions and tolerances specified in Tables 1 and Table 2 for upper kelly box connections. The upper connection is the size and style of the swivel stem box connection, i.e., 4-1/2, 6-5/8, 7-5/8 API Regular. The subs outside diameter and tolerances conform to the larger of either the kelly upper box connection or the swivel stem box connection outside diameter.

Inside Diameter: The maximum inside diameter (d) is the largest allowed for the kelly connection specified in Tables 1 or 2. In the case of step bored subs in which the bore through the upper pin is larger than the bore through the lower pin, the bore through the upper pin should not be so large as to cause the upper pin to have a lower tensile strength or lower torsional strength than the lower pin as calculated per Paragraph A.8.1 of the current edition of API RP-7G.

Mechanical Properties Of Drill Stem Subs

The material used to manufacture drilling subs should have the same mechanical properties as the material used to manufacture drill collars. These material requirements are specified in Tables 2. The surface hardness of the as-manufactured diameter (DR) of type B subs shall be measured per the current edition of ASTM A-370 and conforms to the requirements listed in Tables 2.

Table 1
Table 2
Table 3

Kelly Saver Drilling Subs

Kelly saver subs are drilling subs that are intended for use between the lower end of the kelly and the upper end of the drill pipe. They serve as the make/break connection as drill pipe is added to the drill string. Rubber protectors installed into an O.D. groove are used to protect the inside of the BOPs and upper casing from abrasive wear of the drill pipe tool joints. Sizes: Kelly saver subs are furnished to match the O.D. of the lower end of kelly and drill pipe tool joints. Connections: Kelly saver drilling subs are furnished with box up and pin down right hand rotary shouldered connections. The box connection must be the same as the lower kelly connection and the pin connection must match the drill pipe. Rubber Protectors: Rubber protectors are furnished as slip-on types or as latch-on types. Protector manufacturers provide many different sizes to match the casing I.D. Material: Kelly saver subs are manufactured from drill collar material. Therefore, the material meets the mechanical specifications as defined in Table 2.

Figure 1
Table 4
Table 5
Table 6

RK Pipe & Supply sells a wide variety of new and used drilling equipment including tubular products (drill pipedrill collarsheavy weight drill pipe, spiral weight, etc.), pipe handling equipment (rotary tablesbushings and slipselevatorstongskellysblocks, swivels and hooks, etc.), blowout preventersmud pumps, and many other items.  We handle equipment from multiple manufactures including Gardner Denver, National Oilwell Varco, Continental Emsco, Ideco, MKP, BJ, Webb-Wilson, Baash-Ross, Access Oil Tools (AOT), Wooley, DM, Global, and others.  Please check our online inventory for a full list of what R.K. Pipe has in stock.