Welded cone hole openers are often used as efficient rock-breaking tools in fields like trenchless (HDD) construction and geological drilling. How well they work has a direct impact on the cost and speed of construction. So, how do you pick the best cone hole opener? Today, we’ll talk about three important things to think about when making a choice.

Make sure the cone size fits the drill rig.

It’s not always true that bigger cones are better or that smaller ones are worse. The most important thing is to make sure they work with your drill rig.A small drill rig and big cones together could cause too much torque and a slow reaming speed. On the other hand, using small cones on a big drill rig can speed up wear because of the high torque, and it could even cause serious problems like “broken palms.”

Principles of matching:

73–89mm drill pipe goes with 6½”–8½” cones.

102mm drill pipe goes with 8½”–10″ cones.

Drill pipe 127 to 140 mm should be used with cones 9 to 12.4 inches.

Keep in mind that the size of the drill rig affects the size of the cone.Finding the right match makes things work better.

Match the type of tooth to the hardness of the rock.

Cones with different types of teeth are needed for different formations. Common types are steel teeth (milled teeth) and inserted teeth (tungsten carbide inserts).

Steel-tooth cones: These have taller teeth and are good for fully weathered mudstone and sandy gravel formations because they let you get in quickly.

According to IADC standards, insert-tooth cones come in types like 517, 537, 617, and 637. Each type is best for rocks of a certain hardness.

Suggestions for matching:

Layers of sand and weathered mudstone → Steel teeth

IADC 517 inserts for soft rock (<30 MPa)

IADC 537 and 617 inserts work for medium-hard rock (40–80 MPa).

IADC 637 inserts for hard rock (over 80 MPa)

Picking the right type of tooth not only makes the tool last longer, but it also makes it work better.

Find out how many cones you need based on the size and type of rock.

The number of cones changes based on the size of the cone and how hard the formation is.

Basic rules:

The more cones you use, the smaller the cone;

You need more cones if the rock is harder.

This design makes it easier to break rocks and makes them more stable in hard formations.

To find the right welded cone hole opener, you need to not only match the cone size to the drill rig, but also pick the right tooth type based on how hard the rock is and figure out how many cones you need. Construction can only be efficient, safe, and cost-effective when all three of these things are taken care of.

We hope this guide helps you choose! Please leave a comment if you have any other questions.