
All About Drill Rod
Wodin Inc. Forges a Niche in HDD Market
When looking at the HDD process, it is easy to get caught up looking at the rigs specs: What is the thrust/pullback capacity? How much torque does it have? Sometimes overlooked, however, is the drill rod. Drill rod, after all, is the part of an HDD setup that interacts most closely with the ground. And anyone who has experienced the frustration of a failed drill string knows that high-quality drill rod should be at the top of your list when investing in equipment.
To get some insight on drill rod and the manufacturing process, we talked to Wodin Inc.’s Kristen Holub. Holub is currently the vice president at Wodin Inc., where you will find her either in her office working on customer requirements or down on the shop with her sleeves rolled up working on continual improvements. She received a bachelor degree in business administration from Heidelberg University College from its honors program. She is an advocate for education on forgings, holding classes for customers, employees and the Forging Industry Association.
Here is what Holub had to say:
Briefly describe Wodin Inc. and what you do?
Wodin Inc. is a high-quality forging and machine shop located in Bedford Heights, Ohio. Wodin utilize upsetters and press machines in our forging department. The advantage of using upset forging technology allows our company to make very long forgings with a tight tolerance. This process in many cases is economic for our clients then other alternative technologies. In addition, Wodin has a full-service machine shop that can turn, mill and thread product which allows us the ability to offer our customers a turnkey product. I am currently the Vice President at Wodin Inc. Grant Murphy is our owner and president. As Vice President, I’m responsible for over site of customer projects and production, company improvements, and customer expansion.
How long has Wodin been making drill rod? How did you get involved?
Wodin has been supporting the drill pipe line industry for over 20 years. We have forged drive chucks, drill rods, flanges, forged tubing, and fasteners. Wodin works closely with our customers in helping to develop an overall better product. As an example, Wodin was approached by a drilling company to develop unique long tube forgings with tight tolerances. We were able to work closely with our client to research and develop the necessary tooling and recipe to meet their specified needs for the product. The success of this project and others allowed our involvement with direction drilling to expand.
(From left) Wodin owner/president Grant Murphy and vice president Kristen Holub
What materials are most commonly used? How does materials composition affect the end product in the field?
Alloy steel is the main type of materials used in direction drilling products. These alloy steels have different combinations of elements: Carbon for strength and hardness; Chromium for toughness, resistance to wear, and strength; Molybdenum for corrosion resistance and increased hardness properties; and Manganese, a deoxidizer, for additional increased strength, hardness, harden-ability and resistance to wear.
How have materials changed over the years? How has drill rod design changed?
The grades of alloy steel used have not changed too much over the years, but the requirements of the mechanical properties have. Technology has increased in this field tremendously, resulting in increased strength and wear resistance of the final product. By working with the internal grain flow, the forging process can produce a product that is stronger than the equivalent cast, machined or welded part. Using a forging allows our customer to build equipment that lasts longer and can be pushed harder. In addition, Wodin has been able to develop new forging techniques and tooling allowing us to forge an extensive variety of new shape configurations. The combination of mechanical property technology and production advances in forging have allowed our products to become significantly stronger with increased wear resistance. The advances in the development of directional drilling equipment products now allow the end user the ability to drill through solid rock and other hardened materials in previously inaccessible areas, often miles away from the equipment staging point.
What is the key to good forging?
A key to a good forging is working with the grain flow. It is also controlling when and how long you are in the austinizing stage of the material you are forging. Working with customers to create a forging that is near net shape will also gain strength to the final product. Training employees is also very important when creating a good forging. An educated forge operator understands what is happening to the steel during every stage of the forging process. An educated forge operator can drastically reduce quality issues and troubleshoot problems early when they arise. This is one of the reasons why Wodin takes great care in educating and training our operators.
Forged vs welded — what are the pros and cons?
Forging has been around for ages. The Iron and Bronze Ages were both named after advancements of forging. Welding was introduced by a blacksmith by heating up two separate pieces of metal and smashing them together. Automatic welding has only been around for 100 years. The concept of welding is to bring two separated pieces of metal with different grain flows together through pressure and heat. Forging on the other hand is working with one piece of material to stretch or compress the grain flow to create a different configuration. Most steels have grain flow similar to that of a tree trunk. Forging would take that solid tree trunk and, through heat and pressure, bend or compress the trunk to the desired shape. Whereas welding would take the same tree trunk, cut it (disturbing the grain flow), and then piece it together to the desired shape. No matter how strong that glue or bonding mechanism is, the cuts in the grain flow alone can create stress risers when exposed to various tensile, torque, and/or impact stress. In other words, forging takes the base material and creates a configuration where the strength goes back to the core of the forging. Due to advancements in automated welding technology, if strength is not a high priority, it sometimes can be more cost-effective to weld a product vs. forging, as forging is still very much a manual process.