Strapping Materials, Seals & Tools: Poly, PET and Steel Explained
A practical and technical guide to choosing the right strap, seal and tool for your load—from light bundling to heavy export pallets.
Quick Chooser: What You Need by Load Type
| Load Type | Strap | Closure | Tool |
|---|---|---|---|
| Light bundling, cartons, general dispatch | Poly (PP) Strap | Plastic Seals & Buckles | Plastic Strapping Tools |
| Pallets and general freight (most common) | Polyester (PET) Strap | Plastic Seals & Buckles | Battery Strapping Tool |
| Heavy, rigid or sharp-edged loads | Steel Strap | Steel Strap Seals & Buckles | Steel Strapping Tools |
Poly, Polyester (PET) or Steel: Choosing the Right Strap Material
The strap material does more work than the tool that applies it. Get this choice wrong and you'll either be over-paying for steel on light cartons, or under-securing a heavy export pallet with strap that can't hold retained tension. Here's how the three main materials actually compare.
| Strap Material | Tension Retention | Edge Safety | Best For |
|---|---|---|---|
| Polypropylene (PP) | Lowest of the three—suits light, stable loads | Safe to handle, no sharp edges | Carton bundling, light general dispatch |
| Polyester (PET) | High—holds tension as loads settle in transit | Safe to handle, no sharp edges | Pallets, mixed and export loads, most warehouse strapping |
| Steel | Highest rigidity—least elongation under load | Sharp edges—handle with gloves and edge protection | Heavy, rigid or sharp-edged loads (steel coils, timber, bricks) |
Note: exact breaking strain varies by grade and width within each material. Confirm the specific strap grade against your load and safety factors, or use the enquiry form below and we'll spec it for you.
Steel Strap: Ribbon Wound vs Rope Wound, and Grade Options
Steel strap isn't a single product—coil format and grade both change what it's suited for. Power Packaging's steel strap range is Australian-made, available in 12mm, 15mm and 19mm widths.
Ribbon Wound
Each layer wound directly over the last, on a smaller, lighter coil. Suits portable hand tools and mobile dispensers where the strap needs to be carried or changed over regularly.
Rope Wound (Oscillated)
Spool-wound in a larger format for extended run time. Suits heavy-duty mobile dispenser carts and fixed strapping stations with high daily throughput.
Beyond coil format, grade matters: standard steel strap covers general warehouse unitising and medium-duty palletising, while heat-treated (Magnus) and high-strength (Super/HSA) grades step up break force for structural steel, timber packs and heavy export crates. If you're not sure which grade your load needs, tell us the weight and load type in the enquiry form and we'll recommend a spec.
Strap Seals & Buckles: Matching the Closure to Your Strap
The seal or buckle is the weakest link in a strapped load if it doesn't match the strap material, width and joint method. Getting this wrong is one of the most common causes of a strap letting go in transit.
For Poly & PET Strap
- Friction-weld (via battery tool)—no separate seal needed, fastest joint
- Poly buckles—for manual or low-volume application
- Wire buckles (phosphate-coated)—used with polywoven strap for a strong, re-tensionable join
For Steel Strap
- Standard seals—crimped with a manual or pneumatic sealer, matched to strap width
- Serrated seals—added grip for higher-tension applications
- Seal-less joints—notched directly into the strap itself (e.g. ST-IMA, INCA)—no separate seal to source or lose
View Plastic Seals & Buckles → | View Steel Strap Seals & Buckles →
Tools for Applying Each Strap Type
For a full model-by-model comparison of our Siat battery tools (Viper, GT-Xtreme, GT-One+), see the Siat Strapping Tools guide →
Polyester Strapping & Battery Tools
Battery-powered pallet strapping tools pair well with PET strap for fast, consistent tensioning and sealing.
Siat GT-Xtreme (Battery)
- High-tension: Up to 4,200 N for heavy loads
- Modes: Manual, Semi-Auto, Auto, and Soft
Siat GT-One+ (Battery)
- Versatile all-rounder for 10-16mm strap
- Lightweight: Only 3.7kg including battery
Metal Strap: Manual & Pneumatic Tools
Steel remains the industrial standard for dense or sharp-edged loads. Choose a metal strap tool for ultimate load security.
Siat ST-IMA (Manual Combo)
Seal-less combination tool for 13–19mm steel strap—mobile and durable for manual metal strapping.
View Product →
Siat STSR (Pneumatic)
3-button pneumatic tool, 19–32mm strap, up to 9,000N tension—suited for high-volume benches with consistent low-effort sealing.
View Product →How to choose (quick checklist)
- Load weight & rigidity: light/stable → poly; mixed/most pallets → PET; heavy/rigid/sharp → steel.
- Throughput: higher volumes → battery or pneumatic pallet strapping tools.
- Seal match: always match seal/buckle material and width to the strap—see the seals section above.
- Edge Risk: heavy/sharp → consider metal strap with corner protection.
Frequently Asked Questions
What's the difference between poly strap and polyester (PET) strap?
Poly strap (polypropylene, or PP) is the lighter, lower-cost option for bundling and general carton work. Polyester (PET) strap is stronger, holds tension better as a load settles in transit, and is the standard choice for most pallet strapping. Both are safe to handle with no sharp edges, unlike steel.
When do I need steel strap instead of PET?
Steel is the right choice for heavy, rigid or sharp-edged loads, such as steel coils, timber packs and structural steel, where PET's elongation isn't suitable. For most standard pallets and mixed loads, PET strapping provides sufficient holding power with much safer handling.
What's the difference between ribbon wound and rope wound steel strap?
Ribbon wound strap is coiled in a smaller, lighter format suited to portable hand tools and mobile dispensers. Rope wound (oscillated) strap is spool-wound into a larger coil for extended run time, suited to heavy-duty mobile dispenser carts and fixed strapping stations with high daily throughput.
Do I need a separate seal, or can I use a seal-less tool?
Battery PET tools typically friction-weld the strap ends together, so no separate seal is needed. Manual and pneumatic steel tools usually require a matched seal crimped over the strap ends, unless you're using a seal-less tool like the Siat ST-IMA or INCA, which notch the strap directly.
What steel strap widths and grades do you stock?
We stock Australian-made steel strap in 12mm, 15mm and 19mm widths, in standard, heat-treated (Magnus) and high-strength (Super/HSA) grades, in both ribbon wound and rope wound formats. Tell us your load weight and type in the enquiry form and we'll recommend the right spec.
Not Sure Which Strap, Seal or Tool You Need?
Tell us your load weight, size and environment—we'll spec the strap, seal and tool combo for you.
Prefer to talk it through? Call (02) 9725 2211