Most ferro alloy disputes are not really quality disputes. They are specification disputes, discovered after the material has arrived, because the purchase order said "500 MT Ferro Silicon 75%" and nothing else. Here is what a complete specification covers, and why each line earns its place.
1. Chemistry, as ranges with a basis
State a range for the main element and a maximum for everything else you care about. "75% silicon" is not a specification — it is a nickname.
A workable form looks like this:
| Element | Specification |
|---|---|
| Silicon | 74.0% – 78.0% |
| Aluminium | 1.5% max |
| Carbon | 0.10% max |
| Phosphorus | 0.035% max |
| Sulphur | 0.020% max |
Two things people forget. First, say whether the analysis is on a dry basis — it matters for material shipped in bulk that can pick up moisture. Second, name the analytical method, or at least the standard, if you have a history of results differing between your lab and the supplier's.
Pay particular attention to the elements that are not the headline. Aluminium in ferro silicon, sulphur in ferro chrome, phosphorus in manganese alloys — these are the ones that cause trouble downstream, and they are the ones most often left off the order.
2. Size fraction and fines
Sizing is not packaging trivia; it determines whether the alloy dissolves in time. Undersized material blows away or oxidises on the slag before it dissolves. Oversized lumps are still sitting there when you tap.
State three things:
- The nominal range, for example 10–50 mm or 10–80 mm
- The maximum percentage permitted below the range — the fines limit, commonly 5% or 10%
- The maximum percentage permitted above the range
The fines limit is the one that matters commercially. Material that leaves the plant at 5% fines can arrive at 15% after crushing in transit and transhipment, and if the order is silent on it you have no recourse.
3. Packing
Bulk, 1 MT jumbo bags, 25 kg bags, drums. This affects handling cost at your end, moisture exposure and how easily you can sample on arrival. If you need bags palletised or a particular liner for a hygroscopic product, say so — it is far cheaper to specify than to remedy.
4. Sampling and analysis
This is where most disputes are actually won or lost, and it is the clause most often missing.
Agree, in the contract, before shipment:
- Where sampling happens — at the works, at load port, on discharge, or some combination
- Who does it — the supplier, the buyer, or an independent inspection agency
- The sampling standard, so the method is not open to argument
- How samples are split and retained — typically three parts: buyer, seller, and a sealed umpire sample
The umpire clause
Include one. It says: if the buyer's and seller's results differ by more than an agreed tolerance, the sealed umpire sample goes to a mutually agreed third-party laboratory, whose result is final and binding, with the cost borne by whichever party is further from it.
Without this clause, a chemistry disagreement has no mechanism for resolution and becomes a commercial standoff. With it, disagreements resolve in days.
5. Tolerances and rejection limits
Decide what happens when material lands slightly outside specification, because it will eventually.
Most contracts distinguish between two bands. Within the first, the material is accepted with a price adjustment — pro-rata on the main element, or an agreed penalty scale for an impurity. Beyond the second, the buyer may reject.
Spell both out numerically. "Subject to buyer's approval" is not a rejection clause; it is an argument waiting to happen.
6. Certification
Specify what must accompany the shipment:
- Mill test certificate with heat or lot numbers and full analysis
- Certificate of origin — increasingly important given trade measures on ferro alloys in several markets
- Any third-party inspection certificate you have required
- Where relevant, a REACH or equivalent regulatory declaration, and a current safety data sheet
Confirm the lot numbers on the certificate can actually be traced to the bags you receive. Certification that cannot be tied back to physical material is decorative.
7. Delivery terms and timing
Use an Incoterms rule and name the version — FOB, CFR, CIF and DAP allocate cost and risk very differently, and the rules have been revised. State the shipment window, the tolerance on quantity (±5% and ±10% are both common), and whether partial shipments are permitted.
For anything moving by sea, be explicit about the transfer point for risk. A moisture or contamination problem discovered on discharge turns on exactly this.
8. Payment and documentation
Letter of credit, documentary collection, or open account for an established relationship. If it is an LC, check that the document list matches what your supplier can actually produce — an LC calling for a document nobody can issue is a guaranteed delay, and it is a surprisingly common own goal.
A short checklist
Before releasing a ferro alloy order, confirm it states:
- Chemistry ranges for the main element and maxima for named impurities, with basis
- Size fraction, plus limits on undersize and oversize
- Packing type, and palletisation or lining if required
- Sampling location, sampling party, standard, and an umpire clause
- Tolerance bands with price adjustment, and a defined rejection threshold
- Required certificates, traceable to lot numbers
- Incoterms rule and version, shipment window, quantity tolerance
- Payment terms and a document list your supplier can meet
A note on evaluating suppliers
Price per tonne is the least informative number on a quotation. What actually determines your cost is delivered price per unit of the element you need, adjusted for the recovery you achieve with that supplier's sizing, plus the cost of the variability you have to hold inventory against.
A supplier whose analysis lands in the same part of the range every time is worth a premium over one who is cheaper on average but scatters, because consistency is what lets you tighten your own additions instead of over-adding as insurance.
Worth asking any prospective supplier: are they the producer or a trader — both are legitimate, but it changes who controls consistency; what is the lot-to-lot variation on their key elements; how is sizing controlled and verified; and what happens, procedurally, when a lot lands out of specification.
If you are preparing an enquiry, our ferro alloy range lists the products we manufacture and export, and our team can work through a specification with you. Get in touch with your grade, tonnage and destination.
Frequently asked questions
What size fraction should I order?
It depends on where the alloy goes. Furnace charging usually takes 10–50 mm or 10–80 mm. Ladle additions want smaller and more consistent sizing, commonly 10–50 mm, so the alloy dissolves within the tapping window. Always state a maximum permissible fines percentage.
Who should sample the material, and when?
Agree this before shipment. The common arrangements are sampling at load port by an independent inspection agency, sampling on discharge, or an umpire analysis clause where buyer and seller results differ by more than an agreed tolerance.