Five Things Your Supplier Hopes You Never Check

Information asymmetry is the real issue

Let us be clear: most suppliers are not trying to deceive you. They are running businesses with their own cost pressures, and they price accordingly. But the relationship between buyer and supplier is inherently asymmetric. The supplier knows exactly what the part costs to make. The buyer usually does not.

That asymmetry creates opportunities for margin capture that even well-intentioned suppliers will take advantage of, often without thinking of it as overcharging. Here are five things worth verifying on every significant metal part purchase.

1. Whether market actually went up

The claim: "Raw material costs have increased, so we need to adjust pricing."

The reality: market prices fluctuate daily. A supplier might request a price increase citing rising costs, but by the time the request reaches your desk, the market may have already corrected. In some cases, market actually went down during the period the supplier claims costs rose.

How to check: Pull the market 3-month price for the specific metal on the date of the supplier's last purchase (typically 60 to 90 days before the quote) and compare it to the date of the price increase request. If the metal price dropped or stayed flat during that window, the increase is not justified by raw material costs.

What to say: "We have checked the market data for the period between your likely purchase date and the date of your increase request. The base metal price was flat or declining during that window. Can you help us understand which cost component drove the increase?"

2. What percentage of the part is actually metal

The claim: "Aluminium is up 10%, so the part price goes up 10%."

The reality: Metal is typically only 30 to 50% of the total cost of a finished part. The rest is labour, conversion, tooling, freight, and margin. A 10% increase in the metal price on a part that is 40% metal should produce a 4% increase in the total part price, not 10%.

How to check: Build a rough cost decomposition. What does the raw metal weigh? What is its value at current market? Compare that to the total part price. If metal is less than half the cost, any percentage increase in metal price should be applied only to the metal portion.

What to say: "Our analysis shows metal content is approximately 40% of the part cost. We would expect a 10% market increase to translate to roughly a 4% part price adjustment. Can you walk us through the cost breakdown?"

3. When they purchased the raw material

The claim: The quote reflects current market conditions.

The reality: Suppliers typically buy raw material 60 to 90 days before production. The price they actually paid for the metal may be significantly different from today's spot price. If they bought during a dip and are quoting at a peak, the margin is larger than it appears.

How to check: Ask the supplier when the material was purchased or when the mill order was placed. Cross-reference that date against historical market data. The procurement community on Reddit regularly discusses this timing gap, and experienced buyers know to ask the question.

What to say: "For our cost modelling, can you confirm the approximate date of the raw material purchase for this order? We want to make sure our market benchmark aligns with your actual input cost."

4. Whether tariffs actually apply to the specific product form

The claim: "There is a 25% tariff on this metal, so we have added 25% to the price."

The reality: Tariffs are applied to specific HS codes and product forms. A 25% tariff on raw aluminium ingot does not automatically apply to a semi-finished aluminium bracket manufactured in a third country. The tariff might apply to the raw material input only, or it might not apply at all depending on the country of origin and the degree of transformation.

How to check: Verify the HS code classification for the specific part. Check whether the tariff applies to the product form (raw, semi-finished, finished) and the country of manufacture. Section 232 tariffs in the US, for example, apply to the metal content, not the entire part value.

What to say: "We would like to verify the tariff classification. Can you provide the HS code you are using for this part? Our understanding is that the 25% rate applies to the raw metal content rather than the full part value."

5. What the labour and conversion cost actually is per region

The claim: The quoted conversion cost is competitive for the region.

The reality: Conversion costs vary dramatically by region, and suppliers do not always pass through the savings from lower-cost manufacturing locations. A bracket machined in Shenzhen at £12 per hour machine time might be quoted at a rate that implies £30 per hour, because the buyer does not know the regional benchmark.

How to check: Research typical machine-hour rates and labour costs for the specific manufacturing region. Industry sources, trade associations, and tools like SupplyVerse provide regional benchmarks. Compare the implied conversion cost in the quote to the regional norm.

What to say: "Our regional benchmarking suggests CNC machining rates in your area are approximately £14 to £18 per hour. The conversion component in your quote implies a higher rate. Can you help us reconcile this?"

The common thread

All five of these checks share a common theme: they require data that the supplier has but the buyer typically does not. The shift to intelligent procurement tools is closing that gap. When buyers have access to live commodity intelligence, should-cost models, historical pricing, and regional benchmarks, the information asymmetry shrinks, and pricing becomes fairer for both sides.

You do not need to be adversarial about it. Simply asking informed questions changes the dynamic entirely.