Strapping steel coils, pipe and profiles with steel strap and seals

Steel products are heavy, dense and often sharp-edged. They are also where steel strap remains a common choice, because the strap has to hold a high tension with little stretch and survive contact with hard edges. Getting a steel product to its destination intact depends on two things: a band layout that suits the product’s shape, and a strap, seal and tool combination that has been specified as a set.

This guide covers practical layouts for coils, pipe and profiles, then the selection of strap and seals.

Coils

Coils are usually strapped in two directions.

• Circumferential bands run around the outside diameter. They stop the outer wraps from springing loose and keep the coil’s shape.
• Radial, or through-the-eye, bands pass through the coil’s centre and around the outside. They hold the wraps together across the width and stop the coil from telescoping.

The number of each depends on the coil width, mass and how it will be lifted. Bands must not be positioned where lifting gear or forks will bear on them. Where bands cross the inner or outer edges, protect both the strap and the coil. A coil standing on a skid or cradle may also be banded to it, which is a separate decision from banding the coil itself.

Pipe and tube bundles

Bundles of pipe and tube are typically formed into a hexagonal or square shape and banded at intervals along their length.

• Space bands evenly, with bands near each end so the end pipes cannot slide out.
• Longer or more flexible products need more bands so the bundle does not sag between them.
• Align the pipe ends before banding; staggered ends concentrate load on a few pieces.
• Use spacers or end protection where the product finish matters.

Seals are best placed on a side face of the bundle, where they will not be struck when bundles are stacked or lifted.

Profiles, bars and sheet

Angles, channels, bars and sheet packs are often banded to timber bearers or dunnage so they can be lifted by fork or crane.

• Bearers set the band positions; bands should pass close to each bearer.
• Sharp profile edges need edge protection under the strap, or the strap may be cut under tension.
• Mixed lengths need special care: the shortest pieces must still be held by more than one band.

Our guide to sharp edges and abrasion lists the contact details worth recording before choosing protection.

Choosing strap, seal and tool

ASTM D3953-15 is the specification for flat steel strapping and seals in closing, reinforcing, bundling, unitizing, palletizing, bracing, lifting and lashing. It classifies strap by type and finish and seals by class, finish and style, with cold-rolled carbon steel as the base material. It is a useful vocabulary for an enquiry, even when a buyer is not asking for full compliance.

When specifying, record:

Item	Details to record
Strap	Nominal width, thickness, type or grade, and finish as the supplier names it (for example waxed or zinc coated)
Seal	Width, length, sheet thickness, finish and style (for example snap-on or thread-on)
Joint	Notch or crimp, and the number of notches or crimps the sealer forms
Tool	Tensioner and sealer models, or combination tool
Storage	Indoor, covered or open yard, and expected duration

The joint type determines the tool. Signode’s overview of seal joints explains that notch sealers cut into the seal and strap edges to form a mechanical interlock, and that notch joints are typically used on waxed strap. Crimp sealers press the seal and strap into wavy crimps without cutting and rely on friction. The same page shows that some seal styles are used mainly with one joint type while others, such as thread-on seals, serve both, so check each seal against the sealer it will meet rather than assuming. A seal of the right width can still be wrong for the strap thickness.

Finish matters for products stored outdoors. The ASTM specification distinguishes several strap and seal finishes, so state where and for how long the bundles will be stored and ask which finish the supplier proposes for that exposure. Corrosion eats into the band’s steel section, and rust can stain the product it holds.

Steel’s stiffness has a downside too. The CTU Code text notes that steel band stretches only about 0.3% at its maximum securing load, which makes it prone to losing pre-tension if the cargo shrinks or settles, and that a sealed steel band cannot be re-tensioned. If a product is likely to settle after banding, say so in the enquiry so that the strap choice and band layout can take it into account.

Our steel seal compatibility guide explains how to identify the seal precisely enough to reorder or replace it.

Safety with tensioned steel strap

Steel strap under tension stores energy. When it is cut, the free ends can spring back with force.

• Use a cutter designed for tensioned steel strap, not an improvised tool such as pliers, a hammer or a claw bar.
• Stand to the side of the strap, not in line with it, and keep hands and face clear of the free ends.
• Wear eye protection and cut-resistant gloves when applying or removing strap.
• Collect and dispose of used strap promptly; loose ends on the floor are a trip and cut hazard.

Bundling is not the same as securing

A well-banded coil or bundle is a stable unit. It still has to be secured in the truck, wagon or container. The 2014 IMO/ILO/UNECE CTU Code gives non-mandatory guidance on packing and securing cargo in transport units. Its text treats bundling and strapping as an auxiliary measure that should always be combined with direct or friction securing, and notes that very heavy items such as steel coils may need a combination of blocking and lashing. Banding should be designed so it does not interfere with those measures.

Matching seals to steel strap

For steel strap systems, see YAKU’s steel strapping seals. Seal profile and sheet thickness should be checked against your strap and sealer, and performance values are on request. Share the strap reference, sealer model and application through the enquiry page.