Caldwell Model PCK-SL Locking Screw Type Vertical Lifting Clamp

Locking Screw Type Vertical Lifting Clamp — Versatile Lift, Turn & Pull for Steel Fabrication

The Model PCK-SL-05.00-A Locking Screw Type Vertical Lifting Clamp is a 5-ton capacity, multi-purpose rigging tool engineered for demanding steel fabrication and construction environments. Manufactured by The Caldwell Group under the trusted RENFROE brand, this clamp is designed for lift and turn operations across a full horizontal-through-180° arc, making it suitable for complex positioning tasks beyond simple vertical lifts. It is equally capable of being used as an assembly tool for drawing steel plates and structural members together. Contractors and fabricators who work with heavy plate, structural sections, and welded assemblies will find this clamp an essential part of their rigging inventory.

Unlike standard vertical lift-only clamps, the PCK-SL series features dual lifting eyes that allow repositioning of the lifting shackle for optimized pulling angles, and a locking adjusting screw mechanism that securely accommodates varying plate thicknesses up to 1.5 inches. These capabilities — combined with the clamp's ability to function from horizontal through a 180° arc — set it apart from single-purpose lifting clamps that cannot perform turning or assembly operations.

Key Features & Benefits

Locking Screw Adjustment

The adjusting screw allows the clamp to accommodate various material thicknesses up to 1.5 in. and secures the clamp firmly to the workpiece before lifting. This positive locking action gives contractors confidence that the clamp will remain attached throughout the lift, turn, or pull operation without slipping.

Lift & Turn Through 180° Arc

The PCK-SL is specifically rated for lift and turn operations from the horizontal position through a full 180° arc. This capability allows a single pair of clamps to handle plate flipping, rotation, and repositioning tasks that would otherwise require additional rigging equipment or manual intervention.

Dual Lifting Eyes

Two lifting eyes are built into the clamp body, allowing the operator to reposition the lifting shackle for the best pulling angle relative to the load. This flexibility improves load control during complex lift-and-turn sequences and assembly alignment operations.

Ergonomic Handle for Easy Attachment and Removal

The clamp features an ergonomically designed handle with an overall length of 7.38 in. that makes attaching and removing the clamp more efficient, even in tight working conditions. Faster attachment and removal reduces downtime during high-throughput fabrication operations.

Assembly and Drawing Capability

When used in pairs, the PCK-SL can draw two plates or structural members together or position them at a predetermined location adjacent to each other. This makes the clamp a dual-purpose tool that functions as both a lifting device and a fabrication assembly aid, reducing the number of tools a crew needs on the job.

RENFROE Brand Reliability

The RENFROE brand has been trusted by international lifting clamp users for more than 50 years and is manufactured by The Caldwell Group, Inc. in Rockford, IL. This heritage of quality is backed by a worldwide network of stocking distributors who maintain the same performance and service standards.

Common Applications

Vertical Lifting of Steel Plate

Attach the clamp to the edge of a steel plate to perform a vertical lift with the rigging force aligned directly above the shackle, as intended for vertical lift operations.

Plate Turning and Flipping

Use the clamp — typically in pairs — to rotate or flip steel plate from horizontal through a 180° arc, eliminating the need for manual repositioning of heavy members.

Assembly of Structural Members

The PCK-SL can be used in pairs to draw steel plates, structural members, and welded sections together or position them precisely adjacent to each other for fit-up and welding.

Pulling and Positioning

Beyond lifting, the clamp functions as a pulling tool, allowing fabricators to pull members to a predetermined position using the dual lifting eye configuration to optimize the pulling angle.

Handling Welded Sections

The clamp is suited for handling assembled or welded steel sections that require repositioning or alignment during fabrication without damaging the workpiece surface at the jaw contact point.

Compatible Materials

• Steel plate
• Structural steel members
• Welded steel sections

Product Documents

• Download Catalog
• Download Manual
• Lifting Clamp Survey Report
• Lifting Tool Inventory and Maintenance Form
• Minimum Recommended Clamp Inspections
• Renfroe Repair Kits Catalog

Safety Data Summary

Safe Handling

• Read and understand the operator manual before placing the clamp in service.
• Lock the clamp closed before lifting; never lift with the lock in the open position.
• Do not lift over workers, safety areas, or personnel.
• Do not attach the clamp directly to a crane hook; use a flexible connection between the crane hook and the clamp shackle.
• Do not use a heavy flexible connection that may release the clamp.
• Use the correct capacity clamp for the job; do not use large capacity clamps to lift light loads, and do not overload clamps beyond their rated capacity.
• Use enough clamps to balance the load; do not lift loads that are not balanced.
• Do not side load with a straight shackle clamp.
• Do not lift more than one plate at a time with a vertical clamp.
• Do not lift plate horizontally with a vertical lift-only clamp.
• Do not lift from the bottom of a plate stack.
• Do not alter, grind, weld, or modify the clamp in any manner.
• Secure the load before attaching the clamp.
• Inspect the clamp before each lift and follow all inspection and maintenance instructions in the operator manual.
• Use only RENFROE replacement parts to ensure proper operation of the clamp.
• Attend a RENFROE factory training class to establish proper clamp use.
• Consult the operator manual or factory when in doubt about any application.

Technical Specifications

Frequently Asked Questions

Q: Can this clamp be used for both lifting and assembly tasks?
A: Yes. The PCK-SL-05.00-A is a multi-purpose tool designed for lifting, turning, pulling, and the assembly of steel plates, structural members, and welded sections. When used in pairs, it can draw two plates or members together or position them adjacent to each other at a predetermined location.

Q: What is the maximum plate thickness this clamp can accommodate?
A: The adjusting screw accommodates plate thicknesses up to 1.5 in. for this 5-ton model.

Q: Why does the clamp have two lifting eyes?
A: The dual lifting eyes allow operators to reposition the lifting shackle to achieve a better pulling angle relative to the load, which improves control during turning and pulling operations.

Q: Is this clamp suitable for horizontal plate lifting?
A: No. This is a vertical lifting and turning clamp. It should not be used to lift plate horizontally. It is designed for vertical lift and turn operations through a horizontal-to-horizontal 180° arc.

Q: Can this clamp be modified or repaired in the field?
A: The clamp must not be altered, ground, welded, or modified in any manner. Only genuine RENFROE replacement parts should be used for repairs to ensure proper operation.

Q: How many clamps are typically required for an assembly operation?
A: The PCK-SL is generally used in pairs when drawing two plates or members together or positioning them adjacent to each other.