Re-Certified Heavy Weight

RDT is always looking for ways to improve our customer's bottom-line and to offer options on alternative ways to save money and reuse existing products. Along with our Re-Tool Jointing service, another service we provide that you can choose instead of Re-Tool Jointing is our own Re-Certified process.

Our Re-Tool Jointing service is a process where we remove the old worn out tools joints and replace them with NEW tool joints. Although this process extends the service life of the tubular, the fact is that the tube body that remains still maintains it's existing outside and inside diameters. This means that they are not "new" and no guaranty of NEW can be given for these tubular goods. Although the tube body dimensions are not considered new, they do fall under the criteria that pass for Premium Drill Pipe. An RDT Re-Certified product begins with used Drill Collars that do not meet the dimensional specifications to pass as true Drill Collars. By utilizing used Drill Collar bar stock that does not pass dimensional inspection, RDT can convert this previously used pipe into Heavy Weight Drill Pipe (HWDP) and various drilling accessories, such as Cross-over and Lift Subs. This creates a NEW product that can then be Re-Certified. Not only does this save our customers money on their drilling program, but it also helps our world environmental footprint by coming up with a way to recycle tubular material.


In the 1960s, the manufacturing of HWDP used existing old Drill Collar bar stock as part of the main body while tool joints were stub welded on. This provided a product that was manufactured using 4145HT material for both the tool joints and main body. As the existing stocks of older Drill Collars started to diminish, the industry turned to an economic solution using 1340 steel for the tube and 4145HT for the tool joints. The result was a more economic way to build HWDP while still allowing sufficient operational use.

In the 1980s, the resurgence of having excess Drill Collars in stock allowed a few companies to convert old drill collars into HWDP. The process was named re-manufactured HWDP. However, the name re-manufacture was constantly being confused with Re-Tool Jointing. When RDT began as a company in the mid 2000s, we introduced the name Re-Certified. In summary, the Re-Certified service is really the old way of how the HWDP was first introduced into the drilling market. As stock piles of older Drill Collars are available, the Re-Certified service may become a substantial cost cutting method for our customers.


Instead of selling used Drill Collars as scrap metal, our customer can choose to convert their existing product into HWDP. This enables RDT to offer our customers a couple of different options to select from when it comes to the service life of their used Drill Collars. They can either choose to Re-Tool Jointing or they can have Re-Certified HWDP. Here are a few reasons why choosing the Re-Certified process makes sense:

  1. Meets or even exceeds all API specifications. Re-certified HWDP is built using old Drill Collars which have a tensile equal or greater than 110ksi. New API HWDP has 55ksi tensile.
  2. Re-certified HWDP have the same exact dimensions as a new API HWDP. There are no worn out dimensions in the tool joints nor main body.
  3. Certification Package is given with all mechanical properties.

Same guaranty as a new API HWDP with better mechanical properties.


As with all other products offered by RDT, we have a thorough quality assurance process in place for creating our Re-Certified HWAP. The first step in our Re-Certified process is a thorough inspection of all used Drill Collars. Our Re-Certified HWDP can be built as standard or spiral ranging from 4" to 6-5/8". Due to dimensional constraints, the 3-1/2" HWDP is not an option. Once the used Drill Collar is selected, we cleanout the inside diameter to insure that the inside dimensions are on specification for the tubular size being manufactured. Only the HWDP tube body dimension of the old Drill Collar is used. To each end of the new tubular, RDT will then stub weld our standard 27" long Tool Joints. The total length of the Re-Certified HWDP would be approximately 31.5 feet just as NEW HWDP.

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PO Box 73
9022 Vincik Ehlert
Beasley, TX 77417
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Tel: 979-387-3223
Fax: 979-387-3232

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