The retrievable reverse-circulation overshot can be used for fishing, reverse-circulation, and releasing the fish. During the reverse-circulation operation, it has the two functions of simultaneously completing the grabbing and transmitting the left-hand torque. It can replace the left-hand thread male tap and female tap. Its function is similar to that of the reverse-circulation sub. The difference is that this tool does not need to make up with the fish and can fish the required part of the inner diameter of the fish.
Technical parameters ：
| Model | Specification Size | Fishing Inner Diameter (mm(in)) | Allowable Tensile Force (kN) | Initial Tensile Force and Corresponding Torque | Joint Thread | |
| Tensile Force (kN) | Torque (N·m) | |||||
| DLM-T60 | 2 3/8 | 50.8 (2) | 330 | 147 | 4313 | 2 7/8REG |
| DLM-T73 | 2 7/8 | 57.4 (21/4) 62 (27/16) 69.9 (23/4) 74.2 (299/64) 76.2 (3) 77.9 (33/64) |
500 | 166 | 5799 | NC31 |
| DLM-T89 | 3 1/2 | 76 (3) 77.9 (33/64) 84.8 (311/32) 88.3 (331/64) 90.1 (335/64) |
650 | 166 | 9593 | NC31 |
| DLM-T114 | 4 1/2 | 97.2 (353/64) 99.6 (393/64) 101.6 (4) 102.8 (43/64) 103.6 (45/64) |
850 | 196 | 11522 | 4 1/2REG |
| DLM-T127 | 5 | 108.7 (49/32) 112 (413/32) 114.1 (41/2) 115.8 (49/16) |
860 | 196 | 12320 | 4 1/2REG |
| DLM-T140 | 5 1/2 | 118.6 (443/64) 121.4 (443/4) 124.3 (457/64) 125.7 (461/64) 127.3 (51/64) |
880 | 196 | 13263 | NC50 |
I. Product Features
Releasable Structure Design
Features a controllable release function, enabling rapid unlocking or retraction of components under specific conditions, improving operational flexibility.
High-Strength Material
Made from metal materials (such as alloy steel or stainless steel), possessing excellent wear resistance and impact resistance, suitable for high-load environments.
Precision Machining Process
Finely designed surface grooves and holes facilitate installation and motion guidance, ensuring operational stability and accuracy.
Modular Structure
Compact structure allows for quick assembly or replacement with other components, facilitating maintenance and upgrades.
High Durability
The surface may undergo heat treatment or anti-corrosion treatment, extending service life and adapting to complex working conditions.
II. Application Scope
Automation Equipment
Used in automated mechanical systems requiring linear motion, locking, and release control.
Industrial Machinery Devices
Suitable for machine tools, fixtures, transmission mechanisms, and other scenarios requiring positioning and retraction functions.
Engineering Equipment
Applicable to linkage structures or control components in engineering machinery.
Precision Instruments
Used as guiding or actuating components in equipment with high motion accuracy requirements.
Customized mechanical systems are suitable for various non-standard equipment and can be integrated and designed according to specific needs.
