How to Select a Multi-Span Lifting Beam?
**Multi-span lifting beams (also called adjustable lifting beams)** are mainly used for lifting workpieces that are long, have uneven weight distribution, or require multi-point lifting. When selecting a model, key parameters to consider include load capacity, span, adjustable span range, number of lifting points, and lifting method.
Below is a practical engineering selection guide.
I. Step 1: Determine Basic Parameters (Most Important)
Five core data points must be determined before selection:
1️⃣ Maximum Lifting Weight (Q)
Shoulder weight + Lifting tool weight
Generally, a safety factor of 1.1–1.25 is used.
For example: Workpiece 8t Lifting tool 0.5t
Design load: Q ≈ 8.5–10t
2️⃣ Lifting Point Spacing (L)
The distance between two lifting points on the workpiece.
For example:
Workpiece Lifting Point Spacing
Mold 1.2m
Steel structure 3m
Equipment shell 5m
Multi-hole lifting beams must cover this range.
3️⃣ Number of Lifting Points
Common:
Lifting Point Applicable
2-point lifting: Ordinary components
3-point lifting: Long components
4-point lifting: Large equipment
4️⃣ Lifting Height Limits
Lifting beam height + sling height + workpiece height
Must be less than the factory's net clearance.
In some situations, the following are required:
Low headroom lifting beams
Flat lifting beams
5️⃣ Lifting Methods
Two common methods:
Single-point lifting beam (one lifting lug at the top)
Double-point lifting beam (with double hooks or a balance beam)
II. Step Two: Determine the Lifting Beam Span
The lifting beam length is usually:
Lifting point spacing + allowance on both sides
Empirical formula:
Lifting beam length ≈ Lifting point spacing + 0.5–1m
For example:
Lifting point distance: 4m
Recommended lifting beam length:
4.5–5m
III. Step Three: Select the Hole Spacing and Adjustment Range
The advantage of multi-hole lifting beams is that the lifting points are adjustable.
Common Hole Spacing:
Hole Spacing Applicable
100 mm Fine Adjustment
150 mm Common
200 mm Heavy-duty Lifting Beam
Example:
Lifting Beam Length
6m
Hole Spacing
200mm
Adjustable Range:
0.2m Interval Adjustment of Lifting Points
IV. Step Four: Determine the Structural Form
Common Structures:
1️⃣ I-beam Lifting Beam
Advantages
Low Cost
Simple Manufacturing
Suitable for
Under 10t
Small Span
2️⃣ Box-type Lifting Beam
Advantages
High Strength
Good Rigidity
Suitable for
10–100t
Large Span
3️⃣ Truss-type Lifting Beam
Advantages
Lightweight
Large Span
Suitable for
Extra-long Components
Wind Power, Bridges
V. Step Five: Calculate Key Parameters
Main Calculations:
1️⃣ Lifting Beam Strength
Bending Moment:
M = Q × L / 4
(Simplified Two-Point Lifting)
2️⃣ Deflection
General Requirements:
L / 700 ～ L / 1000
For example:
6m lifting beam
Allowable Deflection
6~8mm
3️⃣ Lifting Lug Strength
Lifting Lug Plate Thickness
Common:
Tonnage Lifting Lug Thickness
5t 20mm
10t 25mm
20t 35mm
50t 50mm
VI. Common Selection Reference
Load Lifting Beam Length Hole Spacing
5t 2–4m 100mm
10t 3–6m 150mm
20t 4–8m 200mm
50t 6–12m 200mm
VII. Engineering Experience Suggestions
① Rated load of lifting beam ≥ 1.25 times the actual load
② Number of holes: The more, the more flexible
③ Try to make symmetrical lifting points
④ For large tonnage loads, box-type structures are recommended.
⑤ For spans exceeding 10m, truss structures are recommended.
✅ In short:
The core selection criteria for multi-span lifting beams are five points:
Load capacity + lifting point distance + adjustment range + structural form + strength verification