Storage Shelf Column with Butterfly Holes – Roll Forming Technology

Storage shelving systems come in a variety of designs, each featuring different column structures. One key distinction lies in the hole patterns punched into the columns. These holes play an important role in connecting beams, enabling flexible adjustment and easy assembly. Among the most popular designs is the butterfly hole, which we will explore in this article along with the corresponding roll forming machine used to manufacture these columns.

Raw material	Galvanized steel
Material thickness	1-2 mm

Rolling shaft material	45# steel with tempering treatment
Shaft diameter	70 mm
Rolling station	18 stations
Work speed	0-12m/min (include hole punching)
Machine frame	Iron casting vertical structure
Machine body	steel plate welded with grinding
Motor brand	Lichao
Work power	7.5 kw+7.5kw  (two motors driving)
Transmission	Chain transmission
Leveling station	5 shafts
Straightening	4 vertical rollers

Why Are There Different Hole Types in Shelf Columns?

The hole patterns on the rack columns (including butterfly holes, diamond holes and eight-slot holes) are selected according to the specific environment and application requirements. Although the overall structure of the rack may be similar, the shape of the holes will affect the installation method, load distribution and price. Generally, the holes are spaced 50 mm apart, so the rack height can be adjusted in 50 mm increments.

The butterfly-shaped hole, named for its resemblance to butterfly wings, offers several benefits:

1. Quick and tool-free installation – Butterfly holes allow for fast assembly using clip-on brackets.
2. Enhanced stability – The design ensures tight fitting between the beam and column, reducing shelf wobble.
3. Ideal for medium-duty storage – These columns are commonly used in mid-range shelf systems, including retail and industrial storage.
4. Compatible with multiple shelf styles – From mobile and pallet shelves to mezzanine and gravity racks, the butterfly design supports modern shelving versatility.

In some cases, round holes are also added to enhance compatibility and increase the flexibility of connections. However, adding round holes may slightly reduce load capacity, depending on the material and hole layout.

Machine Configuration and Customization

When manufacturing shelf uprights with butterfly holes, each column size typically requires a dedicated roll forming machine, while different punching patterns only require die changes, making production more efficient.

For the butterfly-hole style, our roll forming machine features:

1. A robust structure designed for long-term stability and precision.
2. Interchangeable punching dies for multiple hole types.
3. Adjustable roll sets to accommodate various widths and thicknesses.