API drill collar slips Type C safety clamp for oil drilling rig tools

Description

Goldenman API 7K Safety Clamps provide secondary mechanical restraint around flush-joint pipe, drill collars and other tubulars that do not have a sufficiently large external shoulder for conventional handling protection.

The available series includes:

• WA-C Type C Safety Clamp: 3-3/4–15-5/8 in
• WA-T Type T Safety Clamp: 1-1/8–4-1/2 in

The segmented link design allows the clamp circumference to be adjusted by selecting the correct number of links for the actual tubular outside diameter.

Each link contains a gripping insert that contacts the tubular surface when the clamp is tightened. The linked structure distributes contact around the tubular rather than concentrating the gripping force at one point.

Goldenman Safety Clamps are manufactured under the applicable API Spec 7K product scope for safety clamps not used as hoisting devices.

They are supplementary safety tools and must be used with properly selected slips, elevators or other approved primary tubular-handling equipment.

Product Short Description

Goldenman WA-C and WA-T Safety Clamps are multi-link secondary restraint tools for drill collars, flush-joint pipe and tubulars with small or insufficient lifting shoulders.

WA-C configurations use 7–18 links for tubular outside diameters from 3-3/4 to 15-5/8 inches. WA-T configurations use 4–6 links for outside diameters from 1-1/8 to 4-1/2 inches.

The clamp must not be used as an elevator, lifting clamp or primary load-holding device.

Product Highlights

• Manufactured to applicable API Spec 7K requirements
• API 7K Safety Clamps product classification
• WA-C Type C and WA-T Type T configurations
• Complete tubular range from 1-1/8 to 15-5/8 in
• Adjustable multi-link construction
• WA-C configurations with 7–18 links
• WA-T configurations with 4–6 links
• Suitable for drill collars and flush-joint pipe
• Individual gripping inserts around the tubular circumference
• Replaceable links, inserts, pins and tightening components
• Even circumferential gripping arrangement
• Model selection by actual tubular OD
• Dimensional, material and functional inspection
• Replacement and overhaul components available
• Supplied as a secondary safety device
• Not designed or certified as a hoisting device

What Is an Oilfield Safety Clamp?

An oilfield Safety Clamp is a segmented mechanical gripping device installed around a tubular as an additional safety restraint during rig-floor handling.

It is commonly used when the tubular:

• Has no large tool joint
• Has no coupling shoulder
• Has only a small external shoulder
• Cannot be reliably protected by a conventional shoulder-type arrangement
• Requires additional restraint above the primary slips

Typical applications include:

• Drill collars
• Flush-joint pipe
• Selected Heavy Weight Drill Pipe sections
• Small-shoulder drilling tools
• Smooth-body tubulars
• Selected bottom-hole assembly components

The Safety Clamp wraps around the tubular and uses multiple gripping inserts to develop circumferential contact.

It is normally positioned according to the rig procedure in conjunction with the appropriate rotary slips, drill collar slips, spider or other primary holding equipment.

Safety Clamp Is Not a Hoisting Device

The Goldenman WA-C and WA-T Safety Clamps covered by this page are not designed to:

• Lift a tubular from the rig floor
• Suspend a drill collar string
• Replace an elevator
• Replace rotary slips
• Replace Drill Collar Slips
• Carry the full suspended string weight
• Arrest a freely falling tubular
• Serve as a crane lifting clamp
• Be connected directly to lifting slings or wire ropes

The product provides secondary restraint only.

The primary tubular load must be carried by correctly selected and rated equipment such as:

• Rotary slips
• Drill Collar Slips
• Tubing slips
• Casing slips
• Elevators
• Spiders
• Lifting subs
• Approved tubular-handling systems

The current page wording “Usage: lifting” must not be used for this WA-C and WA-T product series.

API 7K Product Classification

The correct API product classification is:

Safety Clamps Not Used as Hoisting Devices

Recommended standard wording:

Manufactured to the applicable current edition of API Spec 7K under Goldenman’s licensed Safety Clamp product scope.

API 7K and API 8C safety-clamp products should not be confused.

Product Position	Applicable Classification
Secondary Safety Clamp not used for hoisting	API Spec 7K
Safety Clamp specifically designed and qualified as hoisting equipment	API Standard 8C
Drill Collar Slips used in a rotary slip bowl	API Spec 7K Rotary Slips
Tubular elevator used for lifting	API Standard 8C Elevator

This page should remain an API 7K non-hoisting Safety Clamp page unless Goldenman has a separate API 8C design, certificate scope and lifting qualification for another product.

Type C and Type T Model Comparison

Comparison	WA-C Type C	WA-T Type T
Main tubular range	Medium and large OD	Small OD
Available OD range	3-3/4–15-5/8 in	1-1/8–4-1/2 in
Number of links	7–18	4–6
Typical applications	Drill collars and large flush-joint pipe	Small drill collars, tools and flush-joint tubulars
Adjustment method	Select correct total number of links	Select correct total number of links
Primary function	Secondary tubular restraint	Secondary tubular restraint
Hoisting use	Not permitted	Not permitted

The overlapping area between approximately 3-3/4 and 4-1/2 inches does not automatically mean that WA-C and WA-T are interchangeable.

Final selection must consider:

• Actual tubular OD
• Link geometry
• Insert profile
• Clamp body dimensions
• Tightening range
• Required contact distribution
• Existing operating procedure

WA-C Type C Safety Clamp Specifications

Tubular OD Range	Metric Reference Range	Total Number of Links
3-3/4–4-5/8 in	95.3–117.5 mm	7
4-1/2–5-5/8 in	114.3–142.9 mm	8
5-1/2–6-5/8 in	139.7–168.3 mm	9
6-1/2–7-5/8 in	165.1–193.7 mm	10
7-1/2–8-5/8 in	190.5–219.1 mm	11
8-1/2–9-5/8 in	215.9–244.5 mm	12
9-1/2–10-5/8 in	241.3–269.9 mm	13
10-1/2–11-5/8 in	266.7–295.3 mm	14
11-1/2–12-5/8 in	292.1–320.7 mm	15
12-1/2–13-5/8 in	317.5–346.1 mm	16
13-1/2–14-5/8 in	342.9–371.5 mm	17
14-1/2–15-5/8 in	368.3–396.9 mm	18

The existing page text also mentions a 3-1/2 in minimum for WA-C, while its published table begins at 3-3/4 in.

Until the factory drawing confirms an additional configuration, the technical table should use the verified minimum of 3-3/4 in.

WA-T Type T Safety Clamp Specifications

Tubular OD Range	Metric Reference Range	Total Number of Links
1-1/8–2 in	28.6–50.8 mm	4
2-1/8–3-1/4 in	54.0–82.6 mm	5
3-1/2–4-1/2 in	88.9–114.3 mm	6

The gap between 3-1/4 and 3-1/2 inches should be checked against the current factory link and insert drawings.

Do not assume that one configuration covers a diameter outside its approved range.

Main Components

A WA-C or WA-T Safety Clamp can include:

• Individual clamp links
• Gripping inserts or buttons
• Insert springs
• Connecting pins
• End links
• Tightening screw
• Nut and handle assembly
• Retaining components
• Identification plate or marking area

The precise construction depends on the approved model.

All links in one clamp assembly should have:

• Matching model designation
• Compatible dimensions
• Consistent insert type
• Similar wear condition
• Correct connecting pins
• Verified assembly orientation

Links from different manufacturers, models or generations should not be mixed without a dimensional and functional review.

Working Principle

The clamp is assembled around the tubular using the number of links specified for the actual outside diameter.

As the clamp is tightened:

1. The link assembly closes around the tubular.
2. Spring-loaded or supported inserts contact the tubular surface.
3. Contact is distributed around the circumference.
4. The inserts develop mechanical grip against downward movement.
5. The clamp provides an additional safety restraint above the primary holding equipment.

Correct performance depends on:

• Correct number of links
• Proper insert contact
• Tubular surface condition
• Clamp tightening
• Link and pin condition
• Correct positioning
• Properly functioning primary slips

Too few links may prevent the clamp from closing correctly.

Too many links may leave the clamp loose or produce an unsuitable tightening position.

How to Select the Correct Safety Clamp

1. Measure the Actual Tubular OD

Measure the tubular at the exact position where the clamp will be installed.

Do not select only from nominal pipe size because the actual OD may be affected by:

• External wear
• Corrosion
• Hardbanding
• Spiral grooves
• Slip recesses
• Elevator recesses
• Upsets
• Tool joints
• Coatings
• Repair welds
• Non-standard machining

The selected clamp must make uniform contact with an approved gripping surface.

2. Identify the Tubular Type

Specify whether the clamp will be used on:

• Slick Drill Collar
• Spiral Drill Collar
• Flush-joint pipe
• Heavy Weight Drill Pipe
• Drill stem sub
• Non-magnetic Drill Collar
• Small-shoulder tool
• Other BHA component

The same OD can have different surface profiles and handling risks.

3. Select WA-C or WA-T

As a general guide:

• Use WA-T for small tubular ODs from 1-1/8 to 4-1/2 in.
• Use WA-C for medium and large tubular ODs from 3-3/4 to 15-5/8 in.

For overlapping sizes, Goldenman should confirm the preferred assembly according to the exact drawing and intended application.

4. Select the Correct Link Quantity

The link quantity controls the clamp circumference.

Confirm:

• Tubular OD
• Total number of links
• End-link arrangement
• Insert type
• Tightening screw engagement
• Remaining adjustment allowance

The clamp should tighten securely without reaching the end of its mechanical adjustment.

5. Check Insert Compatibility

The gripping inserts should be selected according to:

• Tubular material
• Tubular hardness
• Surface condition
• Coating
• Allowable marking
• Corrosion-resistant alloy
• Required gripping resistance

Aggressive inserts can damage:

• Thin-wall tubulars
• Non-magnetic alloys
• Corrosion-resistant alloys
• Chrome surfaces
• Coated tubulars
• Worn drill collars

Reduced-marking inserts may be required for sensitive surfaces, subject to verified gripping performance.

Use with Slick and Spiral Drill Collars

Slick Drill Collars

A slick Drill Collar provides a continuous cylindrical surface that normally allows more uniform insert contact.

The clamp should be positioned away from:

• Threaded connections
• Stress-relief grooves
• Box bore-back areas
• Slip recess transitions
• Damaged hardbanding
• Severe wear zones

Spiral Drill Collars

A Spiral Drill Collar has raised lands and recessed helical grooves.

Before using a standard Safety Clamp, verify that:

• A suitable cylindrical gripping area is available
• Inserts do not bridge across deep grooves
• All links achieve consistent contact
• Spiral lands are not damaged
• The selected location is approved by the operating procedure

A dedicated slip or handling recess may be required.

The phrase “suitable for all Spiral Drill Collars” should not be used without reviewing the actual external profile.

Safety Clamp vs Drill Collar Slips

Comparison	Safety Clamp	Drill Collar Slips
Primary function	Secondary restraint	Primary holding in the slip bowl
Installation position	Around the tubular above the primary holding tool	Inside the rotary-table slip bowl
Load path	Supplementary safety function	Transfers tubular load into bowl and rotary table
Typical construction	Multi-link clamp with inserts	Tapered segmented slip bodies
Main standard scope	API 7K Safety Clamps	API 7K Rotary Slips
Can replace the other tool	No	No

The Safety Clamp should normally be used together with the correctly selected Drill Collar Slips or other approved primary handling equipment.

Safety Clamp vs Elevator

Comparison	WA-C/WA-T Safety Clamp	Tubular Elevator
Main function	Secondary restraint	Hoisting and suspension
Load capacity	Not rated as primary hoisting equipment	Defined rated load
Connection to elevator links	No	Yes
API positioning	API 7K non-hoisting Safety Clamp	API 8C hoisting equipment
Tubular support	Gripping inserts around OD	Shoulder or slip-based lifting interface
Suitable for lifting	No	Yes, within approved rating

A Safety Clamp should never be connected to elevator links, slings or crane hooks.

Avoiding Tubular Crushing and Surface Damage

Excessive tightening can cause:

• Deep insert marks
• Local wall deformation
• Coating damage
• Stress concentration
• Surface cracking
• Damage to non-magnetic material
• Reduced fatigue performance

Risk increases with:

• Thin-wall tubulars
• Corroded pipe
• Incorrect link quantity
• Wrong insert profile
• Uneven insert wear
• Excessive tightening force
• Gripping across a transition
• Contaminated contact surfaces

The required tightening procedure should come from the Goldenman operating manual and the tubular-handling risk assessment.

Do not use uncontrolled impact tools unless the approved procedure specifically permits them.

Common Causes of Clamp Slippage

Incorrect Number of Links

The clamp may not reach the correct closed geometry.

Worn Gripping Inserts

Rounded, broken or polished inserts reduce gripping ability.

Contaminated Tubular Surface

Mud, oil, grease, ice or scale can reduce insert contact.

Mixed Link Components

Links from different models or wear conditions may not distribute contact evenly.

Irregular Tubular Surface

Spiral grooves, hardbanding, severe wear or corrosion can prevent uniform engagement.

Insufficient Tightening

The inserts may not develop adequate contact with the tubular.

Primary Slip Movement

A Safety Clamp is not intended to compensate indefinitely for incorrectly selected or damaged primary slips.

The primary holding equipment must be inspected whenever unexpected tubular movement occurs.

Inspection Before Each Use

Inspect:

• Model identification
• Total number of links
• Individual link bodies
• Link pin holes
• Connecting pins
• End links
• Gripping inserts
• Insert springs
• Tightening screw
• Nut and handle
• Retaining components
• Product markings

Remove the clamp from service if there is evidence of:

• Cracked links
• Permanent deformation
• Elongated pin holes
• Bent or damaged pins
• Missing inserts
• Broken insert teeth
• Seized springs
• Damaged tightening threads
• Unapproved welding repairs
• Severe corrosion
• Mixed incompatible components
• Illegible model identification

Installation and Use Considerations

Before installing the clamp:

1. Confirm the tubular OD.
2. Select the correct model and link quantity.
3. Inspect the primary slips or holding device.
4. Inspect all clamp components.
5. Clean the tubular contact surface.
6. Confirm an approved gripping position.
7. Keep personnel clear of pinch points.

During installation:

• Assemble the clamp evenly around the tubular.
• Verify that all links are correctly connected.
• Check that inserts contact the tubular uniformly.
• Tighten according to the approved procedure.
• Confirm adequate adjustment remains.
• Do not use the clamp to lift or reposition the tubular.

After the primary load has been transferred:

• Check the clamp for movement.
• Confirm the primary slips remain fully seated.
• Keep hands clear of the tubular and clamp.
• Stop the operation if any link or insert is unevenly loaded.

The detailed Goldenman operating manual and rig procedure take precedence over this general guidance.

Maintenance and Storage

After use:

• Remove mud and debris
• Clean all link joints
• Clean the gripping inserts
• Inspect insert springs
• Inspect pin holes
• Lubricate moving joints as specified
• Protect threaded tightening components
• Apply corrosion protection
• Store the complete matched assembly together
• Keep model and link-count identification visible
• Record inspections and repairs

Do not store the clamp in a tightened or permanently deformed position.

Do not mix links from separate assemblies unless compatibility has been formally verified.

Replacement Parts

Available replacement components can include:

• Standard clamp links
• End links
• Gripping inserts
• Insert springs
• Connecting pins
• Retaining pins
• Tightening screw
• Tightening nut
• Handle components
• Fasteners
• Complete WA-C link kits
• Complete WA-T link kits

Replacement parts should be ordered using:

• Clamp type
• Tubular OD range
• Total link quantity
• Existing part number
• Link dimensions
• Insert dimensions
• Current factory drawing

Replacement Compatibility

A replacement Safety Clamp should not be ordered only by the description “Type C” or “Type T.”

Provide:

• Existing manufacturer
• Existing model
• Tubular OD
• Total number of links
• Link dimensions
• Pin diameter
• Insert type
• Tightening mechanism
• Overall closed dimensions
• Existing part numbers
• Clear photographs
• Existing assembly drawing

Similar-looking clamps may have different link pitch, insert pockets, pin sizes and tightening components.

Individual links should not be represented as universally interchangeable without dimensional verification.

Manufacturing and Quality Control

Goldenman manufacturing and inspection procedures can include:

• Raw-material certificate verification
• Heat-number traceability
• Chemical and mechanical property review
• Heat-treatment verification
• Link-body dimensional inspection
• Pin-hole inspection
• Connecting-pin inspection
• Insert-pocket inspection
• Insert material verification
• Insert hardness testing
• Tightening-screw inspection
• Magnetic-particle examination of critical components
• Assembly inspection
• Link-count verification
• Tubular-range fit-up test
• Functional tightening test
• Product marking inspection
• Coating and preservation inspection
• Final documentation review

The final inspection scope should correspond to the applicable API 7K requirements, approved design and purchase order.

Factory Acceptance and Functional Inspection

The agreed inspection can include:

• Approved datasheet review
• Model verification
• Link-count verification
• Material traceability review
• Dimensional inspection
• Pin and hole inspection
• Insert inspection
• Assembly fit-up
• Tubular-size fit test
• Tightening-mechanism test
• Uniform contact inspection
• Release-function check
• Product marking verification
• Documentation review

Because this WA-C/WA-T product is not a hoisting device, the page should not advertise an API 8C elevator proof-load test unless a separate approved testing requirement applies.

Available Documentation

The order documentation package can include:

• API certificate according to Goldenman’s actual licence scope
• Certificate of Conformity
• Approved product datasheet
• Assembly drawing
• Link-quantity chart
• Spare-parts drawing
• Material certificates
• Heat-treatment records
• Hardness report
• NDE report where required
• Dimensional inspection report
• Insert inspection report
• Fit-up and functional inspection record
• Product traceability list
• Operation and maintenance manual
• Inspection and rejection guidance
• Recommended spare-parts list
• Packing list
• Third-party inspection report

Frequently Asked Questions

Is a Type C Safety Clamp the same as a Drill Collar Slip?

No.

The Safety Clamp is a secondary restraint installed around the tubular. Drill Collar Slips are the primary holding tool installed in the rotary slip bowl.

The two products perform different functions and should normally be used together according to the rig procedure.

Can WA-C or WA-T Safety Clamps be used for lifting?

No.

The products on this page are API 7K Safety Clamps not used as hoisting devices. They must not replace an elevator, lifting clamp or other rated hoisting tool.

What is the difference between WA-C and WA-T?

WA-T is designed for smaller tubular outside diameters from 1-1/8 to 4-1/2 inches and uses 4–6 links.

WA-C covers larger outside diameters from 3-3/4 to 15-5/8 inches and uses 7–18 links.

How is the correct number of links selected?

The link quantity is selected from the actual tubular OD and the approved Goldenman size chart.

The assembly should close correctly with adequate insert contact and tightening adjustment. Links should not be added or removed without checking the resulting approved diameter range.

Can one 16-link WA-C clamp fit every pipe close to 13 inches?

No.

The page-listed 16-link configuration covers approximately 12-1/2–13-5/8 inches. The actual tubular OD, external profile and insert contact must still be verified.

Can the clamp be installed directly over spiral grooves?

Not automatically.

A Spiral Drill Collar may not provide uniform insert contact across the grooves. Use an approved cylindrical handling area or dedicated recess after reviewing the actual collar drawing.

Why does a Safety Clamp mark the tubular surface?

The gripping inserts require mechanical contact to provide restraint.

Excessive or uneven marking may indicate the wrong insert profile, incorrect link quantity, excessive tightening, damaged inserts or an unsuitable gripping position.

Can links from two different clamps be mixed?

They should not be mixed unless the model, link dimensions, pin sizes, insert type and manufacturing drawing are verified as compatible.

Mixing components can cause uneven contact and incorrect clamp geometry.

What should be checked when a clamp slips?

Immediately secure the tubular through the approved primary handling system and inspect:

• Link quantity
• Insert condition
• Tubular cleanliness
• Tightening mechanism
• Link and pin condition
• Gripping location
• Primary slips

Do not simply continue tightening without identifying the cause.

Is Type MP included on this page?

The current page contains Type MP image names and quick-detail text, but it does not provide a complete Type MP size table or technical configuration.

Type MP should either be removed from this page or added as a separately verified product section with its own size and link data.

What information is required for replacement links and inserts?

Provide the manufacturer, clamp type, total number of links, tubular OD range, existing part number, pin dimensions, insert dimensions and clear photographs.

A current assembly drawing is the preferred replacement basis.

Information Required for Quotation

Please provide:

• Required model: WA-C or WA-T
• Tubular type
• Actual tubular OD
• Slick or spiral external profile
• Required total number of links
• Existing clamp manufacturer
• Existing model
• Existing link part number
• Insert type
• Reduced-marking insert requirement
• Tubular material
• Surface coating
• Primary slips or holding equipment
• Required spare links
• Required spare inserts
• Required pins and springs
• API certificate requirement
• Inspection requirements
• Third-party inspection requirement
• Quantity
• Destination country
• Required delivery schedule

For replacement orders, also provide the existing assembly drawing, product markings and clear photographs.

Request a Technical Quotation

Goldenman supplies API 7K WA-C and WA-T Safety Clamps for drill collars, flush-joint pipe and other small-shoulder tubulars.

Available configurations cover outside diameters from 1-1/8 to 15-5/8 inches with adjustable assemblies from 4 to 18 links.

Send your tubular OD, external profile, required model, link quantity and spare-parts requirements to:

Email: info@goldenman.com

Goldenman will review the tubular interface and prepare the recommended clamp configuration, link arrangement, technical datasheet and commercial quotation.