Engineered for Strength: How Matrix Threads Deliver Superior Performance

Threads are the most critical element in the drill string. They must resist all the stresses of drilling, endure the wear and tear of make-up and break-out, and in the case of dual tube, must do this with a minimum wall thickness to maximize annular air flow and sample return. All Matrix threaded connections incorporate unique design features to achieve superior performance.

Torque capacity of a joint largely depends on its shoulder area. Matrix maximizes this area by implementing a proprietary “double-shoulder” design consisting of an internal shoulder in addition to the usual external shoulder. This design optimizes coupling strength and gives each rod a greater fatigue resistance, extending the service life of each drill rod while reducing total cost of ownership.

Matrix implements 2-start and 3-start threads in our designs for enhanced makeup/breakout speed. These thread designs use a “Dual-Radius Thread Form” allowing the thread-root radius to be lengthened for increased strength. We have also optimized the taper of each thread for improved torsional strength and more stabbing control.

Another important aspect of our thread design is our stress-relief groove machined above each pin thread. This groove safely redirects the tensile and torsional stresses that would normally be concentrated at the last engaged thread over a larger surface area, thus minimizing the probability of surface crack initiation.

In addition to all these design optimizations, Matrix also implements a controlled steel shot peen operation on all threads. This process generates beneficial compressive residual stresses, increasing resistance to corrosion, fatigue, fretting, galling, and improving lubricant retention.