Caldwell Model LP Vertical Locking Lifting Clamp

Model LP Vertical Locking Lifting Clamp — 1-Ton Ergonomic Plate Turning Clamp

The Renfroe Model LP (LP-01.00-A) is a 1-ton capacity vertical locking lifting clamp engineered for turning single steel plates or structural members from horizontal to vertical and back through a 90° arc. Designed for contractors and rigging professionals who need precise, repeatable plate handling, it combines a pivoting shackle with a Lock Open – Lock Closed mechanism to streamline attachment and removal in demanding jobsite conditions. The Model LP is manufactured by The Caldwell Group and carries the trusted Renfroe sub-brand, backed by more than 50 years of international lifting clamp use.

The Model LP is the lightweight, ergonomic alternative to the heavier Model JP, delivering the same core turn-and-lift functionality in a 5.3 lb. package. Its pivoting shackle permits side loading at rated capacity increments up to 90°, a capability not available on straight-shackle clamps, making it a more versatile choice when load angles vary during the lift.

Key Features & Benefits

90° Plate Turning Arc

The Model LP is specifically designed to turn a single plate or member from horizontal to vertical and back to horizontal through the same 90° arc. This makes it well-suited for fabrication and steel erection tasks where plate orientation must change during handling without re-rigging.

Pivoting Shackle with Graded Side-Load Capacity

The integrated pivoting shackle allows side loading of the lifting shackle at 100% of rated capacity from vertical to 30°, 75% of rated capacity between 30° and 45°, and 50% of rated capacity between 45° and 90°. This de-rating system gives riggers a defined, predictable capacity envelope when load angles shift during a lift, reducing guesswork on the job.

Lock Open – Lock Closed Feature

The Lock Open – Lock Closed mechanism facilitates attaching and removing the clamp from the plate quickly and securely. Locking the clamp closed before a lift is a required safety practice, and the positive locking feature makes this step straightforward for operators.

Lightweight, Ergonomic Design

At 5.3 lbs., the Model LP is the ergonomic version of the Model JP, reducing operator fatigue during repeated attach-and-lift cycles. A lighter clamp body also means less total rigging weight to account for when working near rated lift capacities.

Common Applications

Single Plate Turning

Turn individual steel plates from horizontal to vertical or vertical to horizontal during fabrication, staging, or erection operations. The clamp is rated for one plate at a time and must not be used to lift from the bottom of a plate stack.

Structural Member Handling

Handle single structural members that require reorientation during steel erection or shop fabrication, where controlled turning through a 90° arc is needed.

Side-Pull Lifts

Where the crane or hoist line cannot remain directly vertical above the clamp shackle, the pivoting shackle permits controlled side loading up to 90° from vertical using the defined de-rated capacity schedule.

Compatible Materials

• Single steel plates (up to 0.75 in. maximum thickness)
• Single structural steel members

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's Manual before using the clamp.
• Always 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; always use a flexible connection between the crane hook and the clamp shackle.
• Do not use a connection that may release the clamp.
• Use the clamp within its rated capacity; do not overload the clamp.
• Do not use large-capacity clamps to lift light loads.
• Use enough clamps to balance the load; do not lift unbalanced loads.
• Do not lift more than one plate at a time with a vertical clamp.
• Do not lift a plate horizontally with a vertical lift-only clamp.
• Do not side load with a straight shackle clamp — use the pivoting shackle Model LP for side-load applications.
• Do not misuse the clamp (e.g., do not lift a plate 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.
• Use only Renfroe replacement parts to assure proper operation.
• During turning operations, the edge of the plate opposite the edge to which the clamp is attached should always be in contact with a supporting surface such as a factory floor, and the load on the clamp must not exceed one half of the rated capacity during the turn.
• Consult the Operator's Manual or Renfroe when in doubt about any application.

Technical Specifications

Frequently Asked Questions

Q: Can the Model LP lift more than one plate at a time?
A: No. The Model LP is designed and rated for lifting a single plate or member only. Lifting more than one plate at a time with a vertical clamp is explicitly prohibited.

Q: What is the maximum plate thickness this clamp can grip?
A: The Model LP-01.00-A accommodates a maximum plate thickness of 0.75 in.

Q: Can I side-load this clamp, and if so, by how much?
A: Yes. The pivoting shackle permits side loading at 100% of rated capacity from vertical to 30°, 75% of rated capacity between 30° and 45°, and 50% of rated capacity between 45° and 90°. Side loading beyond 90° is not permitted.

Q: How does the Model LP differ from the Model JP?
A: The Model LP is the lightweight, ergonomic version of the Model JP, providing the same vertical turn-and-lift functionality in a lighter, more manageable package.

Q: Can I attach the Model LP directly to a crane hook?
A: No. Always use a flexible connection between the crane hook and the clamp shackle. Direct attachment to a crane hook is prohibited per the operator's manual.

Q: Are replacement parts available for the Model LP?
A: Yes. Renfroe replacement parts are available. Only genuine Renfroe replacement parts should be used to ensure proper operation of the clamp. Refer to the Renfroe Repair Kits Catalog linked in the Product Documents section.