How to Compare Aluminum Casting Quotes: A Buyer-Side Quote Sheet

# How to Compare Aluminum Casting Quotes: A Buyer-Side Quote Sheet

When procurement compares aluminum casting suppliers, the cheapest line item is rarely the cheapest landed program. One supplier may include CNC machining, pressure testing, dimensional reports, and export packaging. Another may quote a lower casting price but exclude machining datums, inspection records, or tooling maintenance. A third supplier may use a different casting process altogether. This guide gives buyers a quote-comparison sheet for normalizing supplier offers before award.

If you are still preparing the RFQ package, start with the aluminum casting RFQ checklist. If you already have drawings, use the formal RFQ page or the quote-intent page to send the same assumptions to every supplier.

The seven columns your comparison sheet needs

1. Casting process and alloy

Do not compare a gravity-casting quote against a die-casting quote without naming the process difference. Gravity casting, low-pressure casting, die casting, and sand casting create different tooling cost, part cost, porosity risk, tolerance assumptions, and surface-finish outcomes.

For each supplier, record:

• •quoted process route
• •alloy and temper
• •whether process selection is fixed by the buyer or recommended by the supplier
• •whether heat treatment is included
• •whether machining allowance is already considered in the casting model

A quote that says only "aluminum casting" is not ready for award. Ask the supplier to specify process, alloy, and the reason for that route.

2. Tooling cost and tooling ownership

Tooling cost should be separated from part price. Buyers should record:

• •tooling design cost
• •mold fabrication cost
• •core box or insert cost
• •fixture cost for machining or inspection
• •tooling maintenance responsibility
• •ownership after payment
• •storage conditions and tool-life assumption

If one supplier includes machining fixtures and another does not, the first quote may look higher but be more complete. If tooling ownership is unclear, the buyer may be locked into a supplier even after paying for the mold.

3. Casting piece price

The casting price should be compared at the same quantity break. A useful comparison table includes sample quantity, pilot quantity, annual volume, and one higher-volume scenario. For example:

• •20 sample parts
• •200 pilot parts
• •2,000 annual parts
• •10,000 annual parts

Ask whether the quote assumes a single shipment, monthly releases, quarterly releases, or blanket-order scheduling. A supplier quoting a full-container batch may not hold that price for monthly small releases.

4. CNC machining scope

CNC machining is often the largest difference between quotes. Buyers should separate:

• •rough machining vs finished machining
• •datums and locating strategy
• •bores, sealing faces, O-ring grooves, ports, and threads
• •surface roughness requirement
• •deburring and cleaning
• •whether machining is in-house or coordinated with qualified partners
• •whether CMM reports are included

For housings, read the related article on casting plus CNC RFQ packages. Many quote disputes start when the drawing says "machine all critical areas" but does not identify critical datums and inspection points.

5. Inspection and documentation package

Do not assume inspection is included just because the supplier has inspection equipment. Compare:

• •first article inspection
• •CMM report
• •material certificate
• •spectrometer report
• •X-ray or CT sample plan
• •leak-test method and acceptance criteria
• •PPAP or FAI support
• •traceability format

For automotive programs, the documentation package may cost real engineering time. A supplier who includes PPAP support should state what elements are included and what requires separate review.

6. Packaging, Incoterms, and logistics

A casting quote without Incoterms is incomplete. Record:

• •EXW, FOB, CIF, DAP, or DDP basis
• •export packaging standard
• •pallet or crate size
• •corrosion protection
• •carton labeling
• •sea freight or air freight assumption
• •destination port or delivery address

For fragile machined castings, packaging is not cosmetic. Poor packaging can damage sealing faces, threads, and machined bores before the parts ever reach incoming inspection.

7. Quote assumptions and exclusions

This is the most important section of the comparison sheet. Ask every supplier to list what is not included. Common exclusions are:

• •3D model cleanup
• •drawing revision change after tooling release
• •special fixture development
• •destructive testing
• •third-party lab testing
• •salt-spray or coating validation
• •PPAP customer-specific forms
• •expedited air freight
• •tooling modification after first sample

The goal is not to force every supplier to include everything. The goal is to compare the same scope.

A simple buyer-side scoring model

Use a weighted score instead of choosing the lowest price:

This structure helps buyers avoid a common trap: selecting the lowest quote, then paying later through tool changes, inspection gaps, and schedule slips.

Red flags in aluminum casting quotes

Watch for these:

• •no process route stated
• •no tooling ownership statement
• •no machining scope breakdown
• •no inspection deliverables
• •unclear Incoterm
• •price valid only for a vague "annual volume"
• •no note about drawing revision control
• •supplier quotes before asking about alloy, tolerance, leak testing, or machining

If the supplier cannot explain what assumptions sit behind the quote, the quote is not mature enough for supplier selection.

What Bohua needs to quote cleanly

For a comparable quote from Bohua, send:

• •2D drawing in PDF
• •3D model in STEP or IGES
• •alloy or mechanical requirement
• •annual volume and pilot quantity
• •machining scope and critical datums
• •inspection requirements
• •surface finish or coating requirement
• •destination and preferred Incoterm
• •timing target and drawing revision status

Use the request-quote form for a structured RFQ, or start from the quote hub if you are still comparing tooling, MOQ, lead time, and supplier assumptions.

FAQ

Should I compare suppliers by tooling price or part price?

Compare the full program cost. Tooling price matters, but a lower tool cost can be offset by higher piece price, missing machining fixtures, or extra inspection cost. Use a landed-cost model over the expected program volume.

Why do two casting suppliers quote different processes for the same part?

They may have different equipment, tooling philosophy, or risk tolerance. A supplier with only die-casting machines may quote die casting even when gravity or low-pressure casting better fits thick-wall pressure parts. Ask each supplier to explain the process choice.

Should CNC machining be quoted separately?

Yes. Buyers should see casting price and machining price separately, even when the supplier delivers a finished part. This makes it easier to compare datum complexity, inspection needs, and machining risk.

What quote detail helps avoid later price increases?

Clear revision control, machining scope, inspection deliverables, packaging, Incoterm, and tooling ownership. Most price changes happen when those assumptions were vague at RFQ stage.