Double Loop Wire Ties Specifications: What to Put in Your RFQ

A specification for double loop wire tiess is only useful if it is unambiguous to someone who cannot see your project. Most disputes on this product do not come from bad manufacturing — they come from a drawing that could reasonably be read two ways, where the supplier read it the cheap way and the buyer read it the expensive way.

This is a practical specification checklist, written around what the standards actually require.

The three specification families you will meet

Suppliers will quote against whichever family your market uses, and the part can usually be built to any of them:

• ASTM A370 — mechanical testing of wire.
• ASTM A641 — zinc-coated wire (galvanised grades).

The mistake is to specify a standard reference without specifying the class or grade within it. If you write only the standard number, the supplier will quote the lowest class that satisfies it. Write the standard and the level you want.

Dimensional data that has to be on the drawing

For this product the critical dimensions are: wire Ø 1.6–2.5 mm (16–14 ga); lengths 150–600 mm; bagged 100 / 250 / 500 pcs.

Three rules that prevent most dimensional disputes:

1. Give tolerances on every functional dimension, not just the nominal values. A nominal dimension with no tolerance is legally “as the supplier chooses”.
2. Say which dimensions are functional and which are cosmetic. Suppliers prioritise what you prioritise, and they cannot guess.
3. State the gauge or measuring method where a dimension is critical. Two inspectors with different methods will disagree about the same part.

Material and grade

The base specification is soft annealed low-carbon steel wire, looped both ends. Grades commonly offered include:

• black annealed (standard)
• galvanised (outdoor / food-grade yards)
• cut-to-length 150–600 mm
• colour-tagged lengths for fast identification

Ask the supplier to state the grade on the quotation, not on an assumption. Grade substitution is the single most common silent cost reduction, and it is usually invisible in the finished part — a 201 stainless component looks exactly like a 304 one until the second winter.

Surface treatment

The usual finish for this product is black anneal or electro-zinc; ends looped true, no sharp tails.

Two points worth writing into the order:

• A measured requirement, not a process name. “Hot-dip galvanised” is a process; “70 µm minimum, tested by coating mass on three parts per batch” is a requirement.
• What happens at cut edges and drilled holes, if any. These are where coatings are habitually broken and where corrosion starts.

Type tests and routine tests

These are different things and are frequently confused in quotations:

• Type tests qualify the design once. On this product: loop twist test — 4 turns without fracture; tensile per lot; length tolerance ±3 mm.
• Routine tests are run on every batch: loop geometry (closed eye, no burr).

Specify which type-test reports you want supplied as documents, and which routine test results must accompany each shipment. On a first order, ask for the type-test report before you place it.

The failure modes your specification should be closing

• Loops cracking off at the eye — loop formed after the wire cooled past its anneal window; the eye works hardens and parts on the first twist
• Inconsistent length in the bag — cut station drift; workers sort by hand and the crew slows down — tolerance ±3 mm keeps the bag trustworthy
• Sharp loop tails scratching — loop eye left open or tails untrimmed; a scratched hand on every bag is a claim on a food-grade yard

Each of these can be turned into one line in the specification. That is the real purpose of writing it out: not bureaucracy, but making the specific failure you are worried about somebody’s explicit responsibility.

A specification skeleton you can reuse

1. Scope: Double Loop Wire Ties to be supplied as double loop ties, preformed wire ties, loop ties, bale ties with loops, bag ties.
2. Dimensions and tolerances: wire Ø 1.6–2.5 mm (16–14 ga); lengths 150–600 mm; bagged 100 / 250 / 500 pcs.
3. Material: soft annealed low-carbon steel wire, looped both ends; grade black annealed (standard) or better.
4. Standard: ASTM A370 — mechanical testing of wire; ASTM A641 — zinc-coated wire (galvanised grades).
5. Finish: black anneal or electro-zinc; ends looped true, no sharp tails.
6. Tests: loop twist test — 4 turns without fracture; tensile per lot; length tolerance ±3 mm; loop geometry (closed eye, no burr).
7. Marking and packing: bagged by count with silica gel for sea freight; 20 bags per carton.
8. Inspection: pre-shipment, against this specification, with photo evidence and test records.

Related: the double loop wire ties quality inspection checklist turns this specification into an inspection plan you can hand to a third-party inspector.