Moving steel is different from moving almost any other load. It is heavy, often has sharp edges, comes in awkward shapes, and most importantly it usually lacks a built-in lifting point.
You can’t just wrap a synthetic sling around a sharp steel plate (it will cut). You can’t always drill a hole for a shackle (it ruins the integrity). And welding on a temporary lug takes time and certified labor.
In the steel fabrication yards and construction sites we serve at Holloway Houston , clamps are the workhorses of material handling. But they are also precision instruments. A clamp relies on friction and mechanical grip. If you choose the wrong jaw size, or try to lift a plate that is too hard for the clamp’s teeth, gravity will win.
This guide covers the different types of lifting clamps, how to select the right one for your beam or plate, and the critical safety factors required by ASME B30.20.
A lifting clamp is a mechanical gripping device designed to attach a hoist to a load usually a steel plate, beam, or pipe without the need for slings or additional hardware.
Technically classified as Below-the-Hook Lifting Devices under ASME B30.20, they work on a simple principle: the heavier the load, the tighter the grip. Most industrial clamps utilize a cam mechanism where the upward force of the lift drives a serrated jaw into the material.
Industrial lifting clamps grip the load mechanically, providing a secure connection without modifying the workpiece. However, they are strictly rated for specific orientations—vertical, horizontal, or universal. Using a vertical clamp to pull a plate horizontally is a fast way to damage the clamp and drop the load.
Walk into any major fabrication shop, and you will see racks of clamps. Knowing which one to grab is the first step in a safe lift.
These are the most common types. They are designed to lift a single steel plate from a horizontal stack and turn it 90 degrees to a vertical position (or vice versa).
These are designed to lift plates flat (horizontally) without bending them.
Moving I-beams and H-beams is notoriously difficult with slings because the center of gravity shifts easily.
Lifting round stock or pipe is dangerous because it rolls. Pipe clamps use a scissor-action grab or specialized curved jaws to cradle the pipe securely.
These are manually tightened using a screw mechanism rather than relying on the load's weight to actuate a cam.
| Clamp Type | Load Orientation | Material Thickness | Typical WLL | Best Application |
|---|---|---|---|---|
| Vertical | 90° Turn / Vertical | 0" to 4" | 0.5 - 30 Tons | Feeding burn tables, turning plates. |
| Horizontal | Flat Only | 0" to 6" | 1 - 10 Tons (Per Pair) | Moving thin sheets that sag. |
| Beam | Vertical / Horizontal | Flange Width Dependent | 1 - 20 Tons | Lifting I-beams or hanging hoists. |
| Screw | Universal (Static) | Varied | 0.5 - 5 Tons | Temporary anchor points. |
Selecting a clamp isn't just about weight capacity. At Holloway Houston, we see riggers select a 5-ton clamp for a 2-ton load and assume they are safe. Not always.
Here are the three factors that dictate clamp selection:
This is the most overlooked specification. Vertical clamps work by digging teeth into the steel.
Clamps have a minimum and maximum jaw opening (e.g., "0 to 2 inches").
Many cam-action clamps require a certain amount of weight to engage the teeth.
Holloway Houston stocks plate clamps and beam clamps from leading manufacturers like Crosby, IP, and Renfroe, with jaw openings ranging from 0 to 4 inches and capacities from 1 to 20 tons.
A clamp is a dynamic tool with moving parts. It requires more inspection than a shackle or a sling.
Critical Safety Note : Never stand under a load held by a clamp. Unlike a shackle which is a positive connection, a clamp is a friction connection. If the load strikes an obstacle or the crane jerks, the grip can be broken.
We often get asked: "Should I buy clamps or a magnet?" Both lift steel without lugs, but they excel in opposite environments.
For a deeper dive into magnetic lifting, check our guide on Lifting Magnets.
Whether you are erecting structural steel or feeding a plasma table, you need clamps that bite hard and let go only when you say so.
At Holloway Houston, we verify every clamp we sell against ASME B30.20 standards. We stock parts, repair kits, and full replacement units for the top brands in the industry.
Find the right lifting clamp for your steel handling needs. We carry plate clamps, beam clamps, and pipe clamps in a range of capacities.
Lifting clamps are mechanical gripping devices designed to attach a hoist or rigging assembly to steel plates, beams, pipes, and other structural material without slings or drilled lifting points. Most industrial clamps use a cam mechanism: the upward force of the lift drives a serrated jaw deeper into the material surface, creating a grip that increases with load. ASME B30.20 (Below-the-Hook Lifting Devices) covers the design, inspection, and operation framework for this equipment class. Browse Lifting Clamps At Holloway Houston.
Vertical plate clamps are designed to grip a plate in the upright position - they lift from the top edge of a plate and are typically used to turn a plate from horizontal to vertical or to move it in the vertical orientation. Horizontal plate clamps grip a plate while it remains flat and must be used in pairs (minimum) to maintain level orientation. A single horizontal clamp on one edge will cause the load to tilt. The clamp model documentation specifies the rated orientation and minimum number of clamps for each application.
Standard lifting clamp jaws use hardened serrated teeth designed for mild structural steel. Using these jaws on stainless steel, hardened plate, aluminum, or coated surfaces can damage the material surface and may result in inadequate grip if the tooth profile is not compatible with the material hardness. Non-marring clamp variants use high-friction pads instead of teeth and are commonly used for finished, painted, or sensitive material surfaces. Manufacturer documentation specifies the approved material range for each clamp model.
Pre-use inspection of lifting clamps typically covers the jaw and cam condition - worn teeth reduce grip effectiveness - the spring and locking mechanism function, the hoisting eye and swivel integrity, body deformation or cracking, and legibility of the WLL and size markings. Clamps used on material near the limits of their rated plate thickness range warrant extra attention to jaw engagement. ASME B30.20 addresses the inspection criteria for below-the-hook lifting devices. Holloway Houston offers inspection services for rigging hardware customers.
The content provided is for general informational purposes only and is not a substitute for professional advice. Holloway Houston, Inc. is not responsible for any actions taken based on this information.