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Drill Type Underreamer Hole Opener for Drilling Any Application / Environments Rock Formation

1 pcs
Drill Type Underreamer Hole Opener for Drilling Any Application / Environments Rock Formation
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Type: Environmental Rock Formation Drilling
Style: Exploration Mining
Model: Mineral Exploration
Name: Tricone Roller Drill Bits
Use: PDC Cutter
Usage: Downhole Drilling
Functions: Drill Type Underreamer Hole Opener
High Light:

milled tooth drill bit


tricone rock roller bit

Basic Infomation
Place of Origin: USA
Brand Name: ROSCHEN
Certification: ISO
Model Number: 8 1/2″ ~ 56″
Payment & Shipping Terms
Packaging Details: Poly wood box
Supply Ability: 1000 pcs
Product Description

Drill Type Underreamer Hole Opener Suitable for Drilling Any Application and Environments Rock Formation



The Roschen DTU Underreamer has gone through several changes and modifications to adapt to the ever changing drilling applications and environments.

Features and Benefits:

1. Long proven history with over 2.5 million feet underreamed worldwide.
2. Expansion ratios 70% and larger than the OD of the body.
3. Hydraulically expandable with pump pressure.
4. Cutter arms move upward and out simultaneously in the body.
5. Reverse actuating mechanism maintains that tool is open while drill string weight prohibits tool closure.
6. Roller cone cutters are specifically designed for the ROSCHEN DTU underreamers and are consistent with down hole diameters.
7. Proprietary internal "cage" inside of roller cone cutters reduces wear and increases the life of the cutter. 
8. Body machined from heat-treated steel bar, giving it exceptional strength. 
9. Jet nozzles near the cutters allow for cutter washing and cooling. 

10.Cutting Structures available include: 

A. Sealed Bearing Mill Tooth 
B. Sealed Bearing TCI 

4. ROSCHEN's ADD Cutter 

Drilling Type Underreamer


The ROSCHEN Drilling Type Underreamer was created for well bore enlargement in a variety of applications and always being updated to adapt to the drilling environment. Once the under reamer has passed through the restrictions and reached the desired depth, the rotary and pumps are engaged allowing the arms to open. 


1. Cutter arms, which are held in the body by a hinge pin attached to a yoke, move upward and out in the body simultaneously. 
making it virtually impossible for the hinge pins to vibrate loose.

2. Hydraulic power combined with reverse actuating mechanism maintains that the tool is open while drill string weight on cutter arms prevents tool closure.

3. Without changing internal or external parts, the underreamer can be adjusted to any size within its operating range in minimal time in a shop or at a rig site.
4. Roller cone cutters are specifically designed for underreamers. Internal cage reduces bearing revolution thus increasing bearing and seal life of cutter.

5. Machined from heat-treated steel bar giving it exceptional strength. Integral Jet sub near bottom of underreamer allows cutter washing for longer tool life, better penetration rates, and
fewer down hole trips.

6. Jet nozzles in top sub allow for increased GPM through the tool without causing washouts.

7. Tool is activated by pump pressure. In scenarios when tool needs to be closed,(i.e. drilling out shoe track) the tool can be fitted with shear pins to ensure closure until activation is needed.

Technical Specifications: 

Smallest I.D. (in) Recommended Maximum Opening(in) Recommended Drilling Weight (pounds) Max Flow (GPM) Rotary Speed (RPM) Top Connection (Pin) Bottom Connection (Box)
3/4" 8 1/2" 0~7000 350 70~100 3 1/2" Reg 3 1/2" Reg
1" 9 7/8" 0~7000 500 70~110 4 1/2" Reg 4 1/2" Reg
1" 13 1/2" 0~12,000 500 70~110 4 1/2" Reg 4 1/2" Reg
1 1/2" 14 3/4" 0~15,000 900 70~100 4 1/2" Reg 4 1/2" Reg
1 1/2" 22" 0~15,000 1,000 70~100 7 5/8" Reg 6 5/8" Reg
2 1/4" 24" 0~20,000 1,400 70~100 7 5/8" Reg 7 5/8" Reg
2 1/4" 28" 0~20,000 1,400 70~100 7 5/8" Reg 7 5/8" Reg
2 1/4" 30" 0~25,000 1,400 60~110 7 5/8" Reg 7 5/8" Reg
2 1/4" 40" 0~25,000 1,400 50~110 7 5/8" Reg 7 5/8" Reg
2 1/4" 40" 0~30,000 1,400 40~110 7 5/8" Reg 7 5/8" Reg
2 1/4" 50" 0~30,000 1,400 40~80 7 5/8" Reg 7 5/8" Reg


ROSCHEN Cutting Structure Options
Sealed Bearing Mill Tooth
Sealed Bearing Interrupted Mill Tooth
Sealed Bearing Tungsten Carbide Insert
ADD Cutter (Carbide)







Q: Are you a manufacturer or trading company?
A: We are a specialized manufacturer.

Q: What are your main products, and used for?
A: Our products include core bit, PDC bit, reaming shell, core barrel, casing, drill rod, SPT equipment, Shelby sampler, drill rig and other drilling parts.
They are used for mineral exploration, geological drilling, geotechnical engineering and soil sampling.

Q: How about the delivery terms?
1. Payment: T/T, L/C, Western Union, Paypal, 30% deposit in advance and rest before delivery.
2. Min. order quantity: 1 piece.
3. Transportation: By DHL/TNT/Fedex express, air, sea, train.

Q: How about discount?
A: Price is based on products and order quantity.

Q: Do you accept sample order?
A: Yes sure, please contact us for details.

Q: How about your after-sales service?
A: As a manufacturer, we offer promt technology support for all problems and questions. Besides, we accept goods return or replace for quality problem.

Q: How does your company control the quality?
A: Quality first. In order to guarantee high quality for our products, Roschen always makes a serious inspection for all products and raw materials in strict procedure. We have obtained certificate of ISO9001:2000 in 2004.


For more information please contact:



WeChat: +86-137 6419 5009 ; +86-135 8585 5390

WhatsApp: +86-137 6419 5009 ; +86-135 8585 5390

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Contact Person : Bill, George, Michael
Tel : 13764195009
Fax : 86-021-54380177
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