The Top 3 Types Of Strapping Material And Their Uses

Updated October 2026. Originally published June 2020.

Strapping comes down to three materials: polypropylene (PP), polyester (PET), and steel. Each behaves differently under tension, responds differently as a load settles, and demands different tooling. Pick the wrong one and you are either wasting material on a load that needed half as much, or dealing with broken straps, damaged freight and safety incidents on the dock. This guide walks through what each material does, where it belongs, and what has shifted in the market since most buyers last compared them side by side.

Strapping is most often used with stretch wrap to fully secure a pallet load. Before you start comparing materials, use the strapping break strength calculator to confirm the tensile strength your load actually requires, based on weight and number of straps. That number is your starting point.

Polypropylene Strapping

PP strapping is the most versatile and widely used option, well suited for light to medium loads, settling loads, and operations running any level of automation.

PP strap is almost always embossed. The embossed texture adds friction at the joint, increases effective strength, and cuts down on the polymer dust that accumulates in sealing heads over time. It comes in a wide range of widths, tensile strengths and core sizes, so it fits manual buckles, hand tensioners, battery-operated tools, semiautomatic and fully automatic strapping machines.

The defining mechanical trait of PP is its elongation behavior. PP strapping stretches approximately 25% on application and recovers approximately 10% shortly after. That recovery matters: as a pallet or bundle of printed materials settles and compresses during transit, the strap moves with it and holds some residual tension rather than going slack. For loads that are expected to compress, PP handles that shift in a way that PET and steel cannot.

The tradeoff is that PP has lower tensile strength than PET and is more sensitive to UV exposure and elevated temperatures in its standard formulation. Suppliers offer UV-stabilized and heat-resistant formulations that address both issues. If your load will sit on a loading dock in direct sun or move through high-temperature environments, specify the right formulation upfront.

On the virgin vs. recycled question: for machine applications, virgin PP strap runs cleanest. Virgin material is produced from new polymers, has minimal camber, and generates less dust in friction-weld sealing heads. Most machine-grade PP strap is white for this reason. Black strap almost always contains reprocessed content and introduces more camber variability, which can cause jams in semiautomatic and automatic equipment. For manual application, camber is less critical.

Best Uses for Polypropylene Strapping

• Printed materials: newspapers, magazines, direct mail
• Millwork: moldings, trim, banisters
• Flooring: hardwoods, laminates
• Appliances
• Clothing and soft goods
• Food distribution: grocery, produce, frozen and fresh meats, seafood pallets
• Pharmaceutical and drug store distribution
• Hay baling

PP fits almost any light to medium strapping application. For heavier loads or long hauls with multiple stops, read the polyester section before finalizing your choice.

For more detail on sizing PP strap for a specific application, see how to calculate strapping cost and volume and the guidance on how to choose the right strapping material.

Polyester Strapping

PET strapping handles heavy, rigid loads that require high initial tension and need to hold that tension through a long haul or multiple stops. It has largely replaced steel in most non-railroad industrial applications.

PET strap is generally smooth but can be embossed. Its mechanical advantage over PP is tension retention: PET has significantly less tension decay, which means the strap stays tight as a load moves through a multi-stop route or a cross-country haul. For loads where a loose strap at delivery equals a freight claim, that retention difference is the deciding factor.

PET also has higher tensile strength than steel of comparable width and better thermal tolerance than PP. It absorbs impact during transit without snapping, making it the right choice for rigid, dense loads, particularly metals, lumber, masonry and unitized pallets of heavy goods. Unlike steel, PET will deflect slightly rather than cutting into load edges under vibration.

Almost all PET strapping is made from recycled materials, most commonly post-consumer beverage bottles. This is not a new development, but the recycled-content supply picture has become more complex. NAPCOR's 2024 annual analysis, reported by Packaging Dive, shows the U.S. PET bottle collection rate at 30.2% and the North American rate at 39.2%. At the same time, demand for rPET is rising as brands face sustainability mandates. That tightening supply-demand balance can affect availability and consistency for buyers who specify recycled-content PET strapping, so it is worth discussing with your supplier as part of any sourcing review.

For machine applications, recycled-content PET strapping needs to be manufactured to tight tolerances to keep camber in check. Well-made recycled PET strap runs cleanly in semiautomatic and automatic equipment. Lower-quality recycled material introduces the same camber and dust problems as recycled PP. Ask your supplier specifically about machine-grade vs. hand-grade when ordering recycled-content PET.

There is also corded polyester strapping, a woven cloth material joined with wire buckles and tied by hand. It has no stretch, is highly flexible, and is a good choice for irregularly shaped loads where a rigid strap would not seat evenly.

PET Replacing Steel: Where the Line Is Now

The shift from steel to PET across heavy industrial applications is no longer a trend to watch. It has happened. Lumber yards, metal distributors, masonry suppliers and pallet operations that once ran steel now run PET in most cases. The reasons are practical: PET is safer to handle, requires less PPE, and does not create the laceration hazard that steel under tension presents when cut. It also does not rust, which matters for any load exposed to moisture.

The remaining cases where steel still makes sense, or is required, are covered in the steel section below. If you are currently running steel and wondering whether PET can replace it in your operation, the polyester vs. steel strapping comparison covers the decision in detail.

Best Uses for Polyester Strapping

• Metals and steel coils
• Lumber and timber
• Pallets of bottles and cans
• Bricks and tiles
• Cinder blocks and construction materials
• Any heavy load requiring high initial tension held over a long haul or multiple stops

Steel Strapping

Steel strapping is now used primarily where it is required by regulation, specifically for open railroad car shipments, or where load conditions genuinely exceed what PET can handle.

Steel does not elongate and does not recover. Once tensioned, it holds its dimension. That rigidity is the correct choice for a narrow set of applications, and a liability in others. When steel strap wraps around a pallet edge and bends at a right angle, it loses significant strength at that bend point. That is not a specification to work around; it is a fundamental characteristic of the material that limits where steel actually performs as intended.

Railroad shipments where the load is not held within a container are required by the Association of American Railroads (AAR) to use steel strapping. Some AAR-approved PP and PET options do exist for specific applications; confirm with your supplier and verify against current AAR requirements before substituting.

The safety consideration is significant enough to state plainly. Steel strapping under tension stores energy. When cut, it can snap back with enough force to cause lacerations and eye injuries. Proper PPE, trained personnel and safe cut procedures are not optional for anyone handling steel strap on a receiving or shipping dock. This is a meaningful operational cost that does not appear on the material invoice but does appear in incident reports. It is one of the primary reasons operations that can move to PET do.

Best Uses for Steel Strapping

• Open railroad car shipments (AAR-required)
• Heavy manufacturing and industrial equipment where load edges would damage PET
• Steel coils with sharp, unprotected edges
• Construction materials in heavy-duty bundling applications
• Baling wire applications
• Secure closure of metal containers

Factors That Drive Your Material Choice

Load characteristics, shipping distance, tensile strength requirements and tooling all interact. Get one wrong and the others do not compensate.

Load Weight, Size and Edge Conditions

Start with load weight and then factor in the edge condition. A load with sharp, unprotected metal edges can cut a PET strap under tension; edge protectors solve this in most cases and are standard practice. A load with smooth, flat edges gives PET no disadvantage over steel. Awkward or top-heavy loads, such as refrigeration equipment, need enough tensile strength across enough strapping points to prevent tipping, not just sliding. Overstrapping wastes material and cost. Understrapping creates transit failures. Use the break strength calculator to run the numbers for your load before ordering.

Shipping Distance and Load Settling

For loads that compress or settle during transit, PP is the right call: its elongation and partial recovery maintain residual tension as the load shifts. For rigid loads on long-haul or multi-stop routes, PET's lower tension decay keeps the strap tight from origin to final delivery in a way that PP cannot match. Steel holds tension on rigid loads as well, but the handling hazards and edge-bend strength loss mean PET is the better choice for most of those applications today.

Tensile Strength Sizing

Tensile strength is the force required to break the strap. The correct break strength depends on total load weight, number of straps per load, strap width, and the strapping method. Both overbuilding (excessive cost and material) and underbuilding (broken straps, damaged product, safety hazard) are common and avoidable. The strapping break strength calculator gives you a starting point based on your actual load parameters.

Tooling and Machine Compatibility

Material choice and tooling are linked. PP runs in the full range of equipment: manual buckles, hand tensioners, battery-operated tools, pneumatic tools, semiautomatic and fully automatic strapping machines. PET is applied by the same range of tools, though it is more often hand-applied in heavy-duty applications. Steel requires its own dedicated tools and cannot be run through PP or PET equipment.

For machine applications, virgin strap or machine-grade recycled strap is the practical choice. Camber, the curve or irregularity in a coil of strap, causes jams in semiautomatic and automatic equipment, fouls sealing heads and creates safety hazards when strap feeds incorrectly. Recycled-content strap can have more camber variability unless it is manufactured to machine-grade tolerances. Virgin material practically eliminates camber and reduces polymer dust, which extends the time between machine cleanings and reduces maintenance calls. If you are running a manual operation, camber is far less of an issue and recycled content is a reasonable consideration.

A Quick Comparison

For a deeper look at when PET makes more sense than steel for your specific application, see the polyester vs. steel strapping guide. If you are also evaluating how strapping works alongside stretch film on heavy or irregular loads, this overview of pallet wrap covers how the two materials complement each other.

Industrial Packaging, founded in 1953 and based in Webster, Massachusetts, sells polypropylene and polyester strapping alongside the machinery to apply them. Reach out at (800) 233-5288 or through the contact page to discuss your application.

Frequently Asked Questions

More questions plant and purchasing teams ask on this topic.

Can I run recycled-content PET strapping through my automatic strapping machine?

Yes, but the key variable is how well the strap was manufactured. Recycled-content PET strapping made to machine-grade tolerances runs reliably in semiautomatic and automatic equipment. The problem arises with lower-quality recycled material that has excessive camber or inconsistent width, which causes feed jams and sealing failures. When sourcing recycled-content PET for a machine application, ask your supplier explicitly whether the product is rated for machine use and what camber tolerances it meets.

Do I need edge protectors when switching from steel to polyester strapping?

For most loads with smooth or moderately rough surfaces, PET strap seats cleanly without edge protection. Where edge protectors become necessary is on loads with sharp, unprotected metal edges, cut stone, or other surfaces that concentrate load stress on a narrow point of the strap. In those cases, corner protectors distribute the tension across a wider contact area and prevent the strap from cutting through under vibration or impact. Adding edge protectors is standard practice and does not compromise the case for switching from steel.

How does shipping method affect which strapping material I should choose?

Rail transport of uncontained loads is the clearest constraint: the Association of American Railroads requires steel strapping for those shipments, and buyers should verify current AAR specifications before substituting any other material. For over-the-road truck shipments, the choice comes down to load type and haul characteristics: PP for compressible or settling loads on shorter routes, PET for rigid heavy loads on long hauls or multi-stop routes where tension retention matters most. Air freight and ocean container shipments generally follow the same logic as truck, with PET covering most heavy-load scenarios.

Want a Second Set of Eyes on Your Strapping?

If you want to talk through your strapping, your strapping machine or how you buy, start a conversation with Industrial Packaging.