Delta Drill Pipe Connection

Higher torque. Faster drilling. Lower cost of ownership.


With the Grant Prideco™ Delta™ connection, you no longer have to sacrifice performance for cost. With millions of feet of drill pipe using Delta connections in the field, hundreds of wells drilled on land and offshore, and hundreds of thousands of individual connection inspections confirming its ruggedness, Delta is able to benefit your drilling operations while lowering your cost of ownership.

Delta delivers improved overall performance compared to our XT™ connection but with the ease of use and lower cost of maintenance of an API connection.

Extreme performance

Delta belongs to the same torque segment as our XT connection and offers the same hydraulic performance. Through design optimization and balancing of stresses, the connection’s enhanced fatigue resistance eliminates the need for cold-rolling drill pipe connections. In summary, the Delta connection offers:

  • Extreme torque (with as much as 20% more than XT) for drilling more extended-reach wells
  • Enhanced hydraulics (~30-40% reduction in pressure losses compared to API) to promote faster drilling with more downhole tool power and improved hole cleaning
  • Streamlined design to allow using larger drill pipe size, reducing vibrations for better borehole quality

Easy to use and low cost of maintenance

With a deep stab in, more threads engaged through spinning, and a reduced tong-free length on the box tool joint OD, the Delta connection is as easy to run as an API connection—a sentiment confirmed by rig crews we visited.

With up to 50% faster makeup than the XT connection, Delta saves up to 4 seconds on each connection makeup and breakout. This savings reduces tripping time and helps bring forth first oil, earning money for the operator and making a drilling contractor’s rig more attractive.

As the most balanced drill pipe connection we have ever put to market, Delta offers a cost of maintenance comparable to that of an API connection while providing improved performance. With more relaxed inspection criteria and 50% more opportunity to reface the connection, Delta shows a very low recut rate and requires 30% less material to recut the connection. In addition, monitoring of the first 108,000 connection inspections showed Delta requires 3.1 times fewer recuts than XT—meaning cheaper repair bills, fewer pipe movements for repair, and simply less pipe needed as contingency.


Standard Delta Configurations for S135 Grade Drill Pipe


Pipe OD (in.)

Nominal Weight (lb/ft)


Tool Joint OD × ID (in.)

Maximum MUT (ft-lbs)



Delta 377

4.750 × 2.563




Delta 391

4.875 × 2.688




Delta 425

5.250 × 3.000




Delta 494

6.250 × 3.250




Delta 527

6.500 × 3.750




Delta 576

7.000 × 4.250




Delta 544

6.625 × 4.000




Delta 576

7.000 × 4.250




Delta 663

8.000 × 5.000


Contact your Grant Prideco representative for further tool joint OD and ID configurations.

Delta Connection

In engineering, delta indicates the degree of difference. For drill pipe connections, Delta is the difference.

Related Products

Drill Pipe

Built for durability and performance by the industry's leading drill pipe manufacturer

Learn more

Grant Prideco Licensee Network

Supporting our customers is our highest priority. Our expansive network of licensed repair facilities provides global service and support for Grant Prideco products.

Learn more

Running and Handling for Drill Stem Products

Best practices for running and handling to properly care for and maintain your Grant Prideco drill stem products

Learn more

Grant Prideco Technical Resources

Supporting our customers is our highest priority, and we look forward to partnering with you today and every day to achieve lasting success.

Learn more

XT Connections

The original high-performance rotary-shouldered connections

Learn more

GPDS and EIS Connections

Grant Prideco Double Shoulder and EIS connections offer enhanced performance and interchangeability with API rotary-shouldered connections.

Learn more

TurboTorque Connections

Optimized connection configurations that offer more torque, faster makeup, and enhanced performance

Learn more

uXT and uGPDS Connections

High-strength connections designed for demanding drilling applications.

Learn more