Date: Oct 31, 2026
Source: Weifang Far Eastern Machinery/www.chinafareastern.com
Hole openers and reamers fitted with roller cone bits are widely deployed across multiple drilling scenarios. Many clients enquire about the rules for selecting the correct size and quantity of roller cone bits for reamers. Our technical team has sorted out practical selection guidelines for trenchless HDD reamers and vertical water well hole openers.
Generally speaking, larger roller cones are the preferred option. They adopt heavier-duty bearing structures, with lower failure probability, though the purchase cost is higher.
The reaming range is a primary reference index:
• When reaming from 450 mm up to 500 mm, small roller cones are acceptable;
• When reaming from 450 mm up to 600 mm, large roller cones are normally recommended;
• When the reaming size expands from 450 mm to 650 mm (a 200 mm reaming increment), large roller cones are mandatory.
Drilling rig capacity is another critical factor. Large roller cones demand higher torque and are less flexible to operate. A simple analogy: an oversize knife is hard to control while cooking, while a properly sized knife delivers smooth, efficient work.
Core Selection Points
1. Large roller cones feature better performance, longer service life and lower failure risk;
2. Large roller cones come with higher cost, so the project budget needs to be evaluated;
3. Reaming diameter range is a key benchmark for roller cone selection;
4. Rig output torque matters: large rigs can easily drive large roller cones, while small rigs may struggle and face poor operability.
We can design hole opener/reamer as per the end client’s requirement. 
For your upcoming reaming projects, please contact Far Eastern’s engineering team for customised roller cone configuration solutions.
Weifang Far Eastern Machinery focuses on manufacturing API-standard hole openers, reamers, roller cone cutters and tricone bits for HDD, water well, foundation and oilfield drilling.Anything you need more, please contact us sales@chinadrillings.com or contact us by Whatsapp:+86-18563617956
Post time: Oct-31-2026