CAMTOP Tool Joints
API Spec 7 Rotary Shouldered Connections — NC23 to NC70
CAMTOP Tool Joints are the heavy-walled threaded connectors welded to each end of drill pipe, providing the critical rotary shouldered connections that join the drill string. Manufactured from AISI 4145H modified alloy steel with cold-rolled thread roots for maximum fatigue life. Phosphate-coated connections prevent galling and corrosion.
AISI 4145H Modified
285-341 BHN
NC23 – NC70
Product Overview
Tool joints are the heavy-walled threaded connectors friction-welded to each end of drill pipe. The pin end (male, external threads) connects to the box end (female, internal threads) of the adjacent joint, forming the drill string. CAMTOP tool joints feature:
- Cold-Rolled Thread Roots: Superior fatigue resistance compared to cut threads — API and H-90 connection thread profiles
- Phosphate Coated Connections: Protect from environmental corrosion and prevent galling upon initial make-up on the rig floor
- Pressed Steel Thread Protectors: Supplied standard on all connections for safe transport and storage
- Full Traceability: Material certifications and inspection reports furnished with each order
Tool Joint Structure & Dimension Reference
Dimensional reference for pin end and box end terminology used in specifications below.
Technical Specifications
| Tool Joint | Size/Style | Nom.Wt lb/ft | Grade | OD D | ID d | Bevel Df | Pin Lp | Pin Tong | Box Tong | Comb L | DPE | DTE |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NC26 2 3/8IF |
23/8EU | 6.65 | E | 3 3/8 | 1 3/4 | 3 17/64 | 10.00 | 7 | 8 | 15 | 2 9/16 | 2 9/16 |
| X | 3 3/8 | 1 3/4 | 3 17/64 | 10.00 | 7 | 8 | 15 | 2 9/16 | 2 9/16 | |||
| G | 3 3/8 | 1 3/4 | 3 17/64 | 10.00 | 7 | 8 | 15 | 2 9/16 | 2 9/16 | |||
| NC31 2 7/8IF |
2 7/8EU | 10.40 | E | 4 1/8 | 2 1/8 | 3 61/64 | 10 1/2 | 7 | 9 | 16 | 3 3/16 | 3 3/16 |
| X | 4 1/8 | 2 | 3 61/64 | 10 1/2 | 7 | 9 | 16 | 3 3/16 | 3 3/16 | |||
| G | 4 1/8 | 2 | 3 61/64 | 10 1/2 | 7 | 9 | 16 | 3 3/16 | 3 3/16 | |||
| S | 4 3/8 | 1 5/8 | 3 61/64 | 10 1/2 | 7 | 9 | 16 | 3 3/16 | 3 3/16 | |||
| NC38 3 1/2EU |
3 1/2EU | 9.50 | E | 4 3/4 | 2 11/16 | 4 37/64 | 11 1/2 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 |
| X | 4 3/4 | 2 11/16 | 4 37/64 | 11 1/2 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 | |||
| G | 4 3/4 | 2 11/16 | 4 37/64 | 11 1/2 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 | |||
| NC38 3 1/2IF_13.3 |
3 1/2EU | 13.3 | E | 5 | 2 9/16 | 4 37/64 | 12 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 |
| X | 5 | 2 7/16 | 4 37/64 | 12 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 | |||
| G | 5 | 2 7/16 | 4 37/64 | 12 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 | |||
| NC38 3 1/2IF_15.5 |
3 1/2EU | 15.5 | E | 5 | 2 9/16 | 4 37/64 | 12 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 |
| X | 5 | 2 7/16 | 4 37/64 | 12 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 | |||
| 15.5 | G | 5 | 2 1/8 | 4 37/64 | 12 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 | ||
| E | 5 | 2 9/16 | 4 37/64 | 12 | 8 | 10 1/2 | 18 1/2 | 3 7/8 | 3 7/8 |
* Grade: E=External Upset, X=Internal Flush, G=Standard, S=Special. For NC40/NC46/NC50/NC56/NC61/NC70 and 6-5/8FH specifications, contact CAMTOP.
NC = Numbered Connection designation per API. OD/ID/Length dimensions are for standard tool joints. Custom configurations available.
Key Features
Cold-Rolled Thread Roots
Thread roots cold-rolled on API and H-90 connections for maximum fatigue resistance. Significantly longer service life than cut threads in cyclic drilling operations.
Phosphate Coated
All connections are phosphated to protect from atmospheric corrosion during storage and prevent galling upon initial make-up, reducing rig floor damage.
4145H Alloy Steel
Premium modified alloy steel heat-treated to BHN 285-341, with minimum Charpy impact 40 ft-lbs at room temperature for superior toughness.
Thread Protectors Standard
Pressed steel thread protectors supplied on all pin and box connections to prevent damage during transport, handling, and storage.
FAQ
Q: What does NC (Numbered Connection) mean?
NC designations are API standardized numbered connections where the number indicates the pitch diameter in 1/10 inches. For example, NC50 has a 5.0″ pitch diameter. NC connections are interchangeable with corresponding IF (Internal Flush) connections.
Q: How are tool joints attached to drill pipe?
Tool joints are attached by friction welding (inertia welding) to the drill pipe body. This creates a metallurgical bond stronger than the pipe body itself, with a smooth internal bore transition for optimal drilling fluid flow.
Q: What hardness range is standard?
CAMTOP tool joints are heat-treated to BHN 285-341 for standard service. This range provides the optimal balance of strength for torque transmission and toughness to resist impact loading and fatigue cracking.
Q: What size tool joint do I need?
Tool joint size depends on your drill pipe OD, required tensile strength, and planned drilling depth. Generally, larger NC numbers correspond to larger drill pipe and deeper drilling applications. Contact CAMTOP for sizing recommendations.
Order CAMTOP Tool Joints
Specify connection type (NC size), OD, ID, and quantity. Custom hardbanding, special metallurgy, and non-standard lengths available.
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