A practical process-fit RFQ guide for engineers, sourcing teams, and quality managers.
This white paper helps buyers decide when gravity casting fits an A356 or ZL114 part, which drawing details change tooling and machining assumptions, and when to move from design review into a formal RFQ.
RFQ evidence paths
At a glance
Why this matters
Most casting RFQs fail before tooling even starts. The drawing is over-toleranced, the alloy is chosen by habit, and the supplier is judged on piece price instead of process fit.
This guide is built to fix that — fast.
Guide Overview
Compare gravity casting, die casting, and sand casting using real-world design and cost logic instead of generic process charts.
Understand the practical differences between A356, ZL114, and ADC12 before you lock the drawing or RFQ package.
Review wall thickness, draft, fillets, undercuts, parting lines, and gating strategy with gravity-casting-specific guidance.
Set realistic CT6-CT8 expectations, avoid billet-style over-tolerancing, and specify secondary operations only where function requires it.
See when T5 or T6 makes sense, what property gains are realistic, and why porosity control still matters first.
Cover common defects, traceability, and how to ask the right supplier evaluation questions.
Read Online
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Gravity casting sits in the sweet spot between sand casting and high-pressure die casting. It offers stronger, lower-porosity parts than typical die cast alternatives, better repeatability than sand casting, and a much more practical tooling budget for medium-volume engineered components.
Choose gravity casting when the part is too structural for typical thin-wall die casting, too repeatability-sensitive for sand casting, and valuable enough to justify better tooling, tighter process control, and heat-treatable alloys such as A356.
The cheapest quote is often the most expensive outcome. Real comparison should include tooling cost, yield, heat treatment, scrap risk, and the supplier's ability to explain defect modes before production starts.
The full guide walks through alloy selection, DFM rules, tolerances, heat treatment, RFQ structure, and supplier-evaluation questions you can actually use in a sourcing meeting.
Soft lead capture
No forced form. If you want help applying the guide to your own part, send us a drawing and we'll review the alloy, process fit, and manufacturability.
Drawing-Ready RFQ
The guide is useful for research, but sourcing teams get a faster supplier answer when the RFQ separates geometry, alloy, machining, inspection, and commercial assumptions. Use this checklist before asking Bohua to compare process route or tooling fit.
2D drawing plus STEP file, or a clearly marked preliminary sketch if the design is still moving
Part envelope, estimated weight, thinnest and thickest wall sections, and any draft or undercut concerns
A356, ZL114, ADC12, or open alloy note with the mechanical or corrosion requirement behind the choice
Machining datums, critical bores, sealing faces, threaded features, and surface-finish expectations
Annual volume range, project stage, tooling status, sample quantity, and target launch or approval window
Inspection evidence needed, such as CMM, material certificate, X-ray scope, leak test, FAI, or PPAP-style package
| Buyer question | Best next route |
|---|---|
| Still choosing gravity casting vs die casting? | Use the process-selection guide first, then submit a process-fit RFQ when drawings and volume are ready. Open this route → |
| A356/ZL114 route already looks likely? | Use the gravity casting RFQ path with wall sections, heat-treatment target, machining scope, and inspection assumptions. Open this route → |
| The part has leak or pressure risk? | Add leak medium, pressure or hold-time target, acceptance criteria, sealing-face datums, and inspection records before quote comparison. Open this route → |
FAQ
This resource is currently available as an online markdown guide with a direct download link, so buyers can read it instantly or save it for internal review.
It is written for design engineers, sourcing managers, quality teams, and OEM buyers evaluating aluminum gravity casting suppliers and process choices.
Gravity casting is often the right answer for medium-volume structural aluminum parts that need better mechanical performance, heat treatment capability, and repeatability than typical die cast or sand cast alternatives.
Send a 2D drawing, STEP model, target alloy or mechanical requirement, annual volume range, machining scope, critical tolerances, sealing or load-bearing requirements, and any known surface treatment or inspection expectations. This helps the supplier review wall sections, draft, tooling feasibility, and process risk before quoting.
Gravity casting may not be the best fit for very high-volume thin-wall parts where high-pressure die casting tooling economics dominate, or for very large low-volume parts where sand casting may be more practical. The right route depends on geometry, annual volume, alloy, tolerance targets, machining exposure, and validation requirements.
Resource URL: https://www.bohua-casting.com/resources/aluminum-gravity-casting-design-guide
Alloy and process names referenced on this page are technical descriptors of casting options. They are not performance guarantees or supply commitments. Final part-specific performance, certification scope, and inspection plan are determined per RFQ review.
