For export crates carrying heavy machinery, the practical baseline is 1.25 in (32 mm) PET or steel strapping for loads in the 1,000 to 5,000 lb range, stepping up to 1.5 in or 2 in steel when the load exceeds 5,000 lb, has sharp edges, or is exposed to long-haul ocean and rail transit [S1][S5].
Width drives holding force, edge-protection requirements, and machine-tool compatibility; a 1/2 in (12 mm) hand-grade PP strap that tops out near 750 lb nominal break has no business on a crated CNC or a skid-mounted diesel generator [S4].
Width and break-strength map for export-crate loads
Standard industrial strapping widths run 1/4 in (6 mm), 1/2 in (12 mm), 3/4 in (19 mm), 1 in (25 mm), and 1.25 in (32 mm), with steel commonly stocked up to 2 in [S1][S5]. Break strength scales with both width and gauge: 1/4 in machine-grade PP starts around 200 lb nominal, 1/2 in hand-grade PP reaches roughly 750 lb nominal, and 1.25 in PET or steel is the threshold for heavy industrial pallets over 1,000 lb [S4][S5].
For a typical export crate holding a single skid-mounted machine weighing 3,000 to 8,000 lb, four to six transverse straps of 1.25 in PET with a 32 mm edge protector under each strap contact line is the most common specification. Where the crate carries a press, transformer, or engine block above 10,000 lb, 1.5 in or 2 in steel with waxed or painted finish becomes the default, paired with heavier buckles or seals [S1].
PP, PET, and steel: decision criteria for export use
PP (polypropylene) is the economical choice for light bundling and small parcel reinforcement in widths from 1/4 in to 3/4 in, almost always embossed for friction, and is unsuitable as the primary restraint on heavy machinery crates [S4]. PET (polyester) is the workhorse for most industrial pallets and long-haul transport, offering higher retained tension than PP and accepting widths up to 1.25 in for heavy industrial pallets [S5].
Steel is required where the load is rigid, sharp-edged, or exceeds the tension retention that plastic can deliver over multi-week ocean transit, and it remains mandatory for some railroad securement applications [S1][S4]. Composite or woven cord strapping fills the niche for fragile or high-value equipment where plastic is too rigid and steel risks surface damage [S4]. The FMCSA cargo-securement rule requires that the aggregate working load limit of all securement devices be at least one-half the weight of the article being secured, so strap count and break strength must be sized against gross crate weight, not nominal product weight alone [S4].
Tool and machine compatibility by strap width
Strapping width directly governs equipment selection: the Fromm P328 hand tool is specified for 10.0 to 16.0 mm strap only, which excludes it from 1 in and 1.25 in PET and from any steel [S5]. Pneumatic and battery combination tools cover 12 to 19 mm and 16 to 25 mm ranges, and dedicated heavy steel strapping tools are required for 1.5 in and 2 in steel with seal or buckle closures [S1].
For crate operations, mobile semi-auto pallet strappers suit dense pallets staged across multiple warehouse zones, while fixed stations make sense when pallet flow is controlled and line-stop position plus guarding can be engineered in [S2]. A heavy export pallet that settles after strapping needs a PET-capable industrial strapping machine; a machine rated only for light PP is a poor fit because retained tension and seal quality will not survive a container's stack-and-vibration cycle [S2]. For broader context on equipment selection for industrial packaging, the construction machinery and equipment and strapping band reference pages list the typical strap-path and tension ranges that procurement teams should pre-validate with real pallets before signing a purchase order.
Edge protection, seal type, and finish selection
Edge condition is a primary selection driver alongside load weight: sharp-edged metal, tile, boards, pipe, or stone must be paired with an edge protection process, or the strap will show cuts, whitening, or abrasion after movement, regardless of the strap's nominal break strength [S2]. Corner boards and steel-edge protectors are mandatory under every strap contact line on a crated machine crate, and any strap that touches a bare steel or cast-iron surface without a buffer is a freight-claim waiting to happen [S1].
Seal type must match strap material and tool: push-type seals and open-flange seals cover 1/2 in to 3/4 in PP and PET, while 1 in and 1.25 in PET typically use serrated or welded seals, and steel uses crimped seals or buckles sized to the strap width [S1]. Surface finish (painted, waxed, blued, or zinc-coated) is selected by transit environment: waxed or painted steel is the common choice for export crates to resist humidity in ocean containers, and zinc-coated is specified where the crate will sit in covered outdoor storage for months before loading [S1].
Standards, regulations, and documentation for export crates
FMCSA cargo-securement rules in the United States set the working-load-limit floor at one-half the article weight, and international ocean freight typically references the same ratio through the CTU Code and IMO/ILO/UNECE guidelines for packaging of heavy machinery [S4]. Some railroad transport modes still require steel strapping, not plastic, so any shipment that splits between road, rail, and sea needs the most restrictive leg's strap spec [S4].
For European export, the relevant ATEX zone only enters the picture if the strapping operation occurs in a flammable atmosphere; routine crate closing on a shipping dock is not in scope. Documentation that should travel with the crate includes the strap material, width, break strength, seal type, edge-protection method, and the number of straps applied, because end customers and receiving inspectors increasingly reject crates that lack traceable packaging data. Procurement should also confirm the strapping machine head, industrial adhesive for the crate itself, and the industrial borescope used for receiving inspection are all rated for the same load class the strap specification implies.
Specification checklist before placing a strapping order
Document gross crate weight, center of gravity height, and pallet base dimensions before sizing the strap; a 4 ft x 4 ft x 6 ft tall crate with a top-heavy machine will need more transverse straps than a low, wide crate of the same weight [S2]. Specify strap material (PP, PET, steel, or composite), width in inches and millimeters, nominal break strength in pounds, finish, seal type, and edge-protection method in a single line item so the supplier cannot substitute a lighter gauge. Confirm the hand tool or machine head is rated for the chosen width: a P328-class tool will not tension a 19 mm PET strap, and a 1 in PET head will not feed a 1.25 in strap without a shim change.
Real-load testing on a finished crate with the planned strap pattern, edge protectors, and normal forklift handling route is the only reliable proof that the specification will hold. For additional reading on the regulatory and machine-safety side of the build, see the NFPA 79 emergency stop requirements for industrial machinery and the EU AI Act compliance path for machine builders references, which touch the same factory acceptance flow that should also validate the strapping station.