How to Request a Die Casting RFQ

Why a Poorly Structured Inquiry Causes Cost Errors

A vague request for quotation leads to a vague quote. If you send a sketch without material data, the supplier must make assumptions. They may quote a high-end aluminum alloy while you expected zinc. They may assume a 10 percent die life rather than 50 percent. The gap between those assumptions and your actual needs creates pricing errors that are hard to fix later.

A well-structured die casting RFQ removes ambiguity. It tells the foundry exactly what to build, how to build it, and how much to build. This allows the supplier to model the process, calculate die wear, and assign labor hours with precision. The result is a pricing document you can use for budgeting and vendor selection.

Prerequisites Before You Send the RFQ

Before writing the email or filling out a portal form, gather the technical foundation. You need a final or near-final technical drawing. The drawing must include critical dimensions, tolerances, and surface finish requirements. If the drawing is still changing, the quote will expire quickly because the supplier will not commit to a price for a moving target.

Next, choose the material. Zinc and aluminum behave very differently in the press. Zinc offers good detail but lower strength. Aluminum offers strength but different cooling curves. Specify the alloy, such as A380 for aluminum or ZA-100 for zinc. Do not leave this blank.

Finally, define the quantity. A prototype run of 100 pieces costs more per unit than a production run of 10,000. The supplier needs to know if this is a first article, a pilot batch, or long-term production. They also need to know the expected annual volume to determine if the die cost is justified.

Step 1: Attach High Resolution Technical Drawings

Upload the CAD file or the PDF version of your drawing. Do not send a screenshot of a screen. The supplier needs to see thread callouts, hole depths, and fillet radii. If you have multiple views, ensure the top view, front view, and section views are included.

Reason: Ambiguous drawings force the supplier to call you for clarification. Every phone call adds time to the sales cycle. If a thread is not specified, the caster may assume a standard size. If that size does not fit your housing, you need a rework. Rework costs money.

Step 2: Specify Material and Alloy Grade

State the exact alloy in the subject line or the top of the inquiry form. For example, “Aluminum A380 die casting” or “Zinc ZA-100 die casting.” If you are open to alternatives, state that explicitly and ask for a comparison.

Reason: Material choice drives die cost and production speed. Zinc alloys flow differently than aluminum. The foundry must select the right mold temperature and pressure. By specifying the alloy upfront, you help them select the right press and die steel. If you want to compare zinc against aluminum, ask for two separate line items in the quote.

Step 3: Define Tolerances and Surface Finish

General tolerances are often not enough for functional parts. Identify which dimensions are critical. Mark these on the drawing or list them in a separate table. Specify the surface finish, usually measured in microns or Ra.

Reason: Tighter tolerances require more careful die polishing and tighter machining. This increases die cost and slows down production. If you do not specify tolerances, the supplier applies their standard, which may be looser than you need. If your part does not fit the mating component, the quote was accurate, but your design was not.

Step 4: State Quantities and Delivery Schedule

Break the order into batches. For example, “100 pieces for first article inspection” and “2,000 pieces for pilot production.” State the required delivery date for the first batch.

Reason: Lead time depends on die manufacturing. A new die takes weeks to machine and heat treat. If you need the part in two weeks, the supplier must check their schedule and potentially rush the die. Rush work costs more. By stating the date, the supplier can tell you if the schedule is realistic.

Step 5: Request a Die Cost Breakdown

Ask the supplier to separate the die cost from the part cost. The die cost is a one-time investment. The part cost is the variable cost per unit.

Reason: This transparency helps you decide if the part is worth casting. If the die costs a significant amount, you need a higher volume to justify the investment. If the part cost per unit is very low but the die cost is high, you may need to negotiate the die ownership or share the cost with the supplier.

Step 6: Include Quality and Inspection Requirements

State what inspection standards you require. Mention first article inspection, dimensional reports, or material test certificates. If you need specific certifications, list them.

Reason: Quality documentation adds labor time. A simple visual check takes less time than a full dimensional report with a CMM machine. By stating your requirements upfront, the supplier includes the labor in the price. If you change the requirements later, the price changes.

Step 7: Ask for Lead Time and Capacity

Request the estimated lead time for the die and the first shipment. Ask about their current capacity.

Reason: Supply chains have constraints. A foundry may be at full capacity for your material type. Knowing the lead time helps you plan your inventory. It also helps you identify if the supplier can handle your annual volume. If they cannot, you need to find another vendor.

Common Mistakes in Die Casting RFQs

The most common mistake is sending a 3D model without a 2D drawing. A 3D model is great for design but lacks dimensional tolerances. The supplier cannot price a part if they do not know the tolerance stack-up.

Another error is not asking for a die life estimate. Ask how many shots the die is expected to last. A standard aluminum die may last 50,000 shots. A high pressure die may last 100,000 or more. If you plan to run 500,000 shots, you need a different die.

Finally, do not accept a single price without asking for assumptions. Every quote is based on assumptions about die life, scrap rate, and labor. Ask the supplier to list those assumptions in the quote. If their assumptions differ from your reality, the price is wrong.

Step 8: Verify the Supplier Before Awarding

Once you have a few quotes, verify the supplier’s capabilities. Check their facility, their materials inventory, and their quality systems. Do not rely on the quote alone. A low price may hide a high defect rate.

Reason: A cheap die may use inferior steel. A cheap process may produce high flash or porosity. Verify the supplier’s reputation and audit their quality process. This step protects your production line from receiving bad parts.

Final Verification: The Quote Checklist

Before you sign off on a quote, run it through this checklist. Does the quote match your drawing number? Does it list the correct alloy? Does it include the die cost and the part cost separately? Does it state the lead time? If any answer is no, ask for a revised quote. A clear quote is the foundation of a successful sourcing relationship.

Item to Include	Why It Matters
Final 2D Drawing	Defines dimensions and tolerances for machining
3D CAD Model	Helps with mold design and simulation
Material Alloy	Determines press settings and die material
Quantity and Schedule	Drives die cost amortization and labor planning
Surface Finish	Affects die polishing and production speed
Inspection Requirements	Adds labor for testing and documentation