DG Series Drilling Hooks for Rig Hoisting Systems

Description

Goldenman DG Series Drilling Hooks are load-bearing components designed to connect the traveling equipment to the drilling swivel, elevator-link system and other approved rig-hoisting equipment.

The complete product range includes:

• DG135
• DG170
• DG225
• DG315
• DG450
• DG675

Page-listed maximum hook loads range from 1,350 to 6,750 kN, equivalent to approximately 150 to 750 short tons.

Each model incorporates a load-bearing hook body, upper bail and bail-support structure, main hook opening, safety-retaining device, rotation-control mechanism and spring or cushioning arrangement.

The correct model is selected according to the drilling rig rating, maximum hook load, traveling-block interface, drilling-swivel bail dimensions, Elevator Link arrangement, main hook opening, operating temperature and required API Product Specification Level.

Product Short Description

Goldenman API 8C DG Drilling Hooks provide the main load-transfer connection between the traveling block and drilling-rig suspended equipment.

Available models cover compact and medium-capacity rigs through heavy drilling systems requiring hook-load ratings up to 750 short tons.

The hook body and associated load-bearing components are manufactured from controlled high-strength alloy-steel materials and inspected according to the approved manufacturing, NDE and testing procedures.

Product Highlights

• Manufactured to applicable API Standard 8C requirements
• API 8C Drilling Hooks product classification
• DG135 through DG675 model range
• Page-listed hook loads from 150 to 750 short tons
• Main hook openings from approximately 165 to 235 mm
• Spring travel from approximately 140 to 220 mm
• High-strength alloy-steel load-bearing components
• Main hook safety-retaining device
• Hook-body rotation brake or locking mechanism
• Spring or cushioning system for vertical movement
• Compatible with approved drilling swivel bails
• Integration with traveling blocks and Elevator Links
• PSL 1 or PSL 2 according to project requirements
• Low-temperature material options
• Material and heat-number traceability
• Dimensional, hardness and NDE inspection
• Proof-load and functional testing
• Replacement parts and overhaul components available

What Is a Drilling Hook?

A Drilling Hook is a primary load-bearing component in the traveling system of a drilling rig.

Its main function is to suspend and transfer load between the traveling block and equipment such as:

• Drilling swivel
• Power swivel
• Elevator Links
• Tubular elevators
• Kelly and drillstring assembly
• Selected casing-running equipment

In a conventional drilling system, the typical vertical load path includes:

1. Drillstring or casing string
2. Elevator or drilling swivel
3. Elevator Links or swivel bail
4. Drilling Hook
5. Traveling Block
6. Drilling line
7. Crown Block
8. Derrick or mast structure

Every component in this load path must have a compatible rated capacity.

A high-capacity Drilling Hook does not increase the capacity of a lower-rated Traveling Block, swivel bail, Elevator Link or derrick structure.

DG Series Technical Specifications

Model	Page-Listed Maximum Hook Load	Main Hook Opening	Spring Travel	Reference Dimensions	Reference Weight
DG135	1,350 kN / 150 short tons	165 mm	140 mm / 5-1/2 in	2,200 × 720 × 616 mm	1,900 kg
DG170	1,700 kN / 190 short tons	190 mm	180 mm / 7-1/8 in	2,498 × 742 × 678 mm	2,100 kg
DG225	2,250 kN / 250 short tons	190 mm	180 mm / 7-1/8 in	2,545 × 780 × 750 mm	2,180 kg
DG315	3,150 kN / 350 short tons	220 mm	200 mm / 7-7/8 in	2,953 × 890 × 830 mm	3,410 kg
DG450	4,500 kN / 500 short tons	220 mm	200 mm / 7-7/8 in	2,953 × 890 × 880 mm	3,500 kg
DG675	6,750 kN / 750 short tons	235 mm	220 mm / 8-5/8 in	3,730 × 1,210 × 975 mm	7,300 kg

The table reproduces the reference data currently published by Goldenman.

Final hook load, opening dimensions, spring travel, overall dimensions and weight must be confirmed through the current Goldenman engineering drawing, product nameplate and Certificate of Conformity.

DG135 Drilling Hook

The DG135 is the smallest model in the current Goldenman series.

Its page-listed specifications include:

• Maximum hook load: 1,350 kN
• Approximate load class: 150 short tons
• Main hook opening: 165 mm
• Spring travel: 140 mm
• Reference weight: 1,900 kg

It may be considered for:

• Compact drilling rigs
• Workover rigs
• Shallow and medium-depth wells
• Lower hook-load operations
• Smaller drilling swivels
• Rig refurbishment projects

The DG135 should still be selected from the complete hoisting-system load analysis rather than nominal rig depth alone.

DG170 Drilling Hook

The DG170 provides an intermediate capacity between the DG135 and DG225.

Its page-listed maximum hook load is 1,700 kN.

The existing Goldenman page converts this to 190 short tons. Because similar DG170 product tables often use a nominal 200-short-ton description, Goldenman should confirm the official rated-load marking used on its drawing and nameplate.

Other page-listed data include:

• Main hook opening: 190 mm
• Spring travel: 180 mm
• Reference weight: 2,100 kg

DG225 Drilling Hook

The DG225 is a 2,250 kN / 250-short-ton-class Drilling Hook.

It can be considered for:

• Medium drilling rigs
• Drillstring and casing operations
• Conventional kelly drilling systems
• Compatible 250-ton Traveling Blocks
• Rig replacement and modernization

Its listed main hook opening is 190 mm, with a spring travel of 180 mm.

The drilling-swivel bail dimensions must be checked against the main hook opening and contact profile.

DG315 Drilling Hook

The DG315 is a common heavy-duty configuration with a page-listed maximum hook load of:

• 3,150 kN
• Approximately 350 short tons

Its reference specifications include:

• Main hook opening: 220 mm
• Spring travel: 200 mm
• Overall dimensions: 2,953 × 890 × 830 mm
• Weight: approximately 3,410 kg

The DG315 may be suitable for medium-to-deep drilling rigs and heavy casing-running operations.

DG450 Drilling Hook

The DG450 is designed for high-capacity drilling operations requiring a page-listed maximum hook load of:

• 4,500 kN
• Approximately 500 short tons

Its reference specifications include:

• Main hook opening: 220 mm
• Spring travel: 200 mm
• Reference weight: 3,500 kg

The DG450 may be used in:

• Deep-well drilling rigs
• Heavy drillstring operations
• Large casing programs
• High hook-load land rigs
• Selected offshore drilling systems
• Replacement of compatible 500-ton-class hooks

DG675 Drilling Hook

The DG675 is the largest model on the current Goldenman page.

Its reference specifications include:

• Maximum hook load: 6,750 kN
• Approximate load class: 750 short tons
• Main hook opening: 235 mm
• Spring travel: 220 mm
• Overall dimensions: 3,730 × 1,210 × 975 mm
• Weight: approximately 7,300 kg

This model requires a full compatibility review covering:

• Traveling Block
• Derrick or mast capacity
• Drilling line
• Crown Block
• Drilling swivel bail
• Elevator Links
• Rig-floor tubular-handling equipment
• Installation and maintenance clearances

Drilling Hook vs Hook Block

A Drilling Hook and Hook Block are related but different products.

Comparison	Drilling Hook	Hook Block
Basic structure	Independent hook assembly	Traveling Block and hook integrated into one assembly
Upper interface	Connected to a compatible Traveling Block	Sheaves and hook form one combined unit
Main function	Suspends swivel, links and hoisting equipment	Provides reeving movement and hook suspension
API 8C category	Drilling Hooks	Traveling Blocks and/or Hook Blocks
Replacement data	Hook load, bail interface and hook opening	Sheave count, line diameter, reeving and hook load
Direct interchangeability	No	No

The Goldenman DG135–DG675 table describes standalone Drilling Hooks rather than complete Hook Blocks.

Drilling Hook vs Clevis or Link Adapter

A clevis, connector or link adapter is an intermediate connecting component.

It does not provide the complete functions of a DG Drilling Hook, such as:

• Main swivel-bail hook
• Safety-retaining system
• Rotating hook body
• Rotation brake
• Spring or cushioning travel
• Side-link handling arrangement
• Full drilling-hook load path

The word “Clevis” should therefore be removed from the primary product name.

When Goldenman supplies separate Block-to-Hook Adapters, Connectors or Link Adapters, those components should have their own API 8C product page and specification table.

Maximum Hook Load

Maximum hook load is the approved vertical load that the hook can support under the specified design and operating conditions.

It must not be confused with:

• Proof-test load
• Design verification load
• Breaking load
• Dynamic shock load
• Derrick capacity
• Traveling Block capacity
• Drillstring weight in air
• Nominal rig tonnage alone

The selection review should consider:

• Drillstring weight
• Bottom-hole assembly weight
• Casing-string weight
• Tubing-string weight
• Drilling-fluid buoyancy
• Overpull allowance
• Stuck-pipe contingency
• Dynamic hoisting effects
• Block acceleration and deceleration
• Offshore rig movement
• Applicable operator safety factors

The allowable operating load is limited by the lowest-rated component in the complete hoisting system.

Main Hook Opening and Swivel Bail Compatibility

The main hook opening must fit the drilling-swivel or power-swivel bail.

Compatibility should be checked using:

• Hook opening width
• Hook throat geometry
• Hook-body section
• Swivel-bail width
• Swivel-bail cross-section
• Contact radius
• Required articulation
• Safety-latch clearance
• Wear allowance
• Operating angle

A swivel bail that physically enters the hook opening is not automatically compatible.

Incorrect contact geometry can create:

• Edge loading
• Concentrated bearing stress
• Restricted articulation
• Excessive hook wear
• Swivel-bail wear
• Side loading
• Safety-latch interference

A dimensional interface drawing should be approved before replacement.

Spring Travel and Cushioning

The listed spring travel provides controlled vertical movement within the hook assembly.

Depending on the approved model design, this system may help:

• Reduce shock during connection breakout
• Protect drill pipe and tool joints
• Reduce impact during load transfer
• Improve handling during kelly and swivel operations
• Accommodate limited vertical movement

Spring travel must not be interpreted as additional lifting height or permission for shock loading.

The model datasheet should identify:

• Spring type
• Spring quantity
• Initial preload
• Working travel
• Maximum permitted travel
• Cushioning arrangement
• Inspection and replacement criteria

Where a hydraulic buffer is fitted, its pressure, fluid, seals and maintenance requirements should be stated separately.

Rotation and Locking Mechanism

A Drilling Hook normally needs controlled rotational movement so suspended equipment can be aligned during drilling and tubular-handling operations.

The DG Series page states that the hook incorporates a braking device that can lock or release hook-body rotation.

The locking system should provide:

• Free rotation when alignment is required
• Positive locking when rotation must be prevented
• Clear operating position
• Reliable engagement
• Protection against unintended release
• Accessible inspection and maintenance

Before loading, verify that the brake or lock is in the position required by the operating procedure.

The rotation lock should not be used to absorb uncontrolled power-tong reaction torque.

Main Hook Safety Device

The main hook requires a reliable retaining or safety device to reduce the risk of the swivel bail or connected equipment leaving the hook opening unintentionally.

Before operation, inspect:

• Safety latch
• Latch pin
• Return spring
• Locking surface
• Hook throat
• Bail seating
• Closing clearance
• Mechanical damage
• Corrosion
• Unauthorized modification

The hook should not be loaded when the safety device:

• Does not close fully
• Is bent or cracked
• Has missing parts
• Interferes with the swivel bail
• Has been tied open
• Has an unapproved field repair

Elevator Link Interface

During tubular-handling operations, Elevator Links may be supported from the hook’s designated link-supporting areas or side hooks, depending on the approved design.

The compatibility review should include:

• Elevator Link model
• Rated load
• Upper-eye dimensions
• Link-body diameter
• Link length
• Contact radius
• Side-hook or support geometry
• Available articulation
• Clearance from the main hook and swivel

The Drilling Hook, Elevator Links and elevator must be treated as one hoisting assembly.

Elevator Links should not be suspended from an unapproved part of the hook body.

Traveling Block Compatibility

The upper hook bail and bail-support assembly must match the Traveling Block.

Provide:

• Traveling Block manufacturer
• Traveling Block model
• Rated load
• Lower connection dimensions
• Bail dimensions
• Pin or connector arrangement
• Required articulation
• Available installation space
• Existing hook drawing

A DG450 Hook should not be assumed compatible with every 500-ton Traveling Block.

Different equipment can have different:

• Bail widths
• Connection pins
• Support radii
• Centerline heights
• Overall dimensions
• Lubrication arrangements

PSL 1 and PSL 2

The purchaser should specify the required API 8C Product Specification Level.

PSL selection can affect applicable:

• Design documentation
• Material controls
• Heat-to-product traceability
• Mechanical testing
• Impact testing
• Heat-treatment records
• NDE
• Proof-load testing
• Product marking
• Documentation

The quotation, manufacturing record and Certificate of Conformity should identify the supplied PSL.

Material and Casting Controls

The Goldenman page states that the hook body, bail and bail support are produced from special alloy steel.

For cast load-bearing components, manufacturing controls should address:

• Material grade
• Chemical composition
• Casting procedure
• Heat treatment
• Mechanical properties
• Impact toughness
• Hardness
• Internal soundness
• Surface discontinuities
• Repair controls
• Heat-number traceability

The phrase “high-quality alloy casting” should not replace a defined material specification.

The supplied documentation should identify the actual material grade and applicable acceptance requirements.

Low-Temperature Service

Drilling Hooks used in cold regions or offshore environments may require verified low-temperature toughness.

The purchaser should specify:

• Minimum design temperature
• Minimum operating temperature
• Required impact-test temperature
• Material toughness requirements
• Offshore or arctic environment
• Applicable operator specification

A standard ambient-temperature hook should not automatically be used for severe low-temperature service.

Inspection Before Each Use

Inspect the hook for:

• Hook body cracks
• Main hook opening wear
• Hook-throat deformation
• Safety-latch operation
• Upper bail condition
• Bail-support condition
• Side-hook or link-support wear
• Rotation-lock operation
• Spring or cushioning condition
• Pins and retaining components
• Lubrication
• Corrosion
• Product identification
• Rated-load marking
• PSL marking where applicable

Remove the hook from service when there is evidence of:

• Cracking
• Permanent bending
• Excessive throat opening
• Severe wear
• Heat damage
• Unauthorized welding
• Seized rotation
• Failed latch
• Broken spring components
• Missing identification
• Load above the marked rating

Replacement Hook Compatibility

A replacement Drilling Hook should not be ordered using only its nominal tonnage.

Provide:

• Existing manufacturer
• Model
• Serial number
• Maximum hook load
• PSL
• Main hook opening
• Hook-body diameter
• Spring travel
• Upper bail dimensions
• Traveling Block model
• Swivel model
• Swivel-bail dimensions
• Elevator Link model
• Overall dimensions
• Product weight
• Existing drawing
• Inspection history
• Clear photographs

Two DG450 Hooks can have similar rated loads but different upper-bail, main-hook and locking-system dimensions.

Manufacturing and Quality Control

Goldenman manufacturing and inspection controls can include:

• Material-certificate verification
• Heat-number traceability
• Casting-process control
• Heat-treatment record verification
• Mechanical-property testing
• Impact testing where required
• Hardness testing
• Dimensional inspection
• Main hook opening inspection
• Bail and bail-support inspection
• Ultrasonic examination
• Magnetic-particle examination
• Surface inspection
• Safety-latch inspection
• Rotation and brake test
• Spring-travel verification
• Assembly inspection
• Proof-load testing under the approved procedure
• Post-load dimensional inspection
• Post-test NDE where required
• Rated-load marking verification
• Final documentation review

The exact inspection and test scope depends on the model, PSL, API requirements and purchase order.

Factory Acceptance Test

The agreed FAT can include:

• Approved datasheet review
• General assembly drawing verification
• Material traceability review
• Mechanical-property report review
• Overall dimensional inspection
• Main hook opening measurement
• Upper-bail interface inspection
• Safety-latch functional test
• Hook rotation test
• Rotation-brake or locking test
• Spring-travel test
• Proof-load test
• Post-load dimensional inspection
• Post-load NDE
• Product marking verification
• Documentation review

The proof load and acceptance criteria must follow the applicable API 8C requirements and approved product procedure.

Available Documentation

The documentation package can include:

• API 8C certificate according to Goldenman’s active scope
• Certificate of Conformity
• Model-specific datasheet
• General assembly drawing
• Traveling Block interface drawing
• Swivel-bail interface drawing
• Elevator Link interface data
• Material certificates
• Casting records
• Heat-treatment records
• Mechanical-property reports
• Impact-test reports where required
• Hardness report
• Ultrasonic inspection report
• Magnetic-particle inspection report
• Dimensional inspection report
• Safety-device functional report
• Rotation and brake test report
• Spring-travel test report
• Proof-load test report
• Post-test inspection report
• Product traceability record
• Operation and maintenance manual
• Inspection and rejection criteria
• Recommended spare-parts list
• Third-party inspection report

Recommended Spare Parts

A model-specific spare package can include:

• Main hook safety latch
• Latch pins
• Latch springs
• Rotation-lock components
• Brake components
• Bearings or bushings
• Main spring components
• Cushioning-system seals
• Pins and retainers
• Lubrication fittings
• Approved fasteners
• Inspection-critical overhaul kit

Load-bearing replacement components must match the approved model drawing and material requirements.

Frequently Asked Questions

Is this product a Clevis or a Drilling Hook?

It is a DG Series Drilling Hook.

Clevises, connectors and link adapters are separate API 8C product categories and should not be used as the main product name for the DG135–DG675 series.

Is a Drilling Hook the same as a Hook Block?

No.

A standalone Drilling Hook connects to a separate Traveling Block. A Hook Block integrates the Traveling Block sheave assembly and hook into one unit.

Does DG450 mean the hook weighs 450 tons?

No.

DG450 refers to a model with a page-listed maximum hook load of 4,500 kN, approximately 500 short tons. Its physical weight is approximately 3,500 kg.

Does DG675 mean a 675-ton rating?

The model has a page-listed maximum hook load of 6,750 kN, approximately 750 short tons.

The model number should not be used as a substitute for the marked rated load.

Can a DG450 replace any 500-ton drilling hook?

Not automatically.

The upper bail, Traveling Block connection, main hook opening, swivel-bail profile, spring travel, overall dimensions and Elevator Link arrangement must all be verified.

What is the purpose of spring travel?

Spring or cushioning travel helps control limited vertical movement and reduce impact during selected drilling and connection-handling operations.

It does not permit shock loading or operation above the rated capacity.

Can the hook rotation lock absorb Power Tong reaction torque?

No.

Connection reaction torque should be controlled by an approved backup tong or reaction system. The hook brake is intended to control hook-body rotation, not absorb uncontrolled tong loads.

Can Elevator Links be installed anywhere on the hook body?

No.

Elevator Links must engage the designated, approved supporting interface shown on the hook drawing.

What should be checked when matching the hook to a drilling swivel?

Check the swivel-bail width, cross-section, contact radius, required articulation, hook opening and safety-latch clearance.

Can a worn main hook opening be repaired by welding?

Load-bearing weld repair must not be performed without an approved manufacturer procedure, engineering evaluation, qualified welding procedure, heat treatment and NDE requirements.

Unauthorized field welding can change the hook’s material properties and invalidate its certification status.

What documents should be supplied with an API 8C Drilling Hook?

Depending on the specified PSL and purchase order, the package can include material records, NDE reports, dimensional inspection, proof-load report, Certificate of Conformity and API documentation.

Information Required for Quotation

Please provide:

• Required DG model
• Required maximum hook load
• Drilling-rig model
• Traveling Block manufacturer and model
• Traveling Block rated load
• Upper hook-bail interface dimensions
• Drilling swivel manufacturer and model
• Swivel-bail dimensions
• Main hook opening requirement
• Elevator Link manufacturer and model
• Required spring travel
• Required rotation-lock arrangement
• PSL 1 or PSL 2
• Minimum operating temperature
• Land or offshore application
• API Monogram requirement
• Material and impact-test requirements
• NDE requirements
• Proof-load witness requirement
• Third-party inspection requirement
• Required spare-parts package
• Quantity
• Destination country
• Delivery schedule

For replacement projects, also provide the existing nameplate, serial number, assembly drawing and clear photographs.

Request a Technical Quotation

Goldenman supplies API 8C DG Series Drilling Hooks for drilling, workover and rig-refurbishment projects.

Available models include DG135, DG170, DG225, DG315, DG450 and DG675, with page-listed maximum hook loads from 150 to 750 short tons.

Send your required hook load, Traveling Block, drilling swivel, bail dimensions, Elevator Link and PSL information to:

Email: info@goldenman.com

Goldenman will review the complete hoisting interface and prepare the recommended Drilling Hook model, dimensional drawing, inspection plan and commercial quotation.