When you’re preparing to request a quote for cast components, a clear and complete drawing isn’t just helpful – it’s essential.
At Fowler & Holden, we’ve quoted thousands of jobs over the decades. The difference between a clean RFQ and an unclear one can mean days of delay, missed tolerances, or even a quote that doesn’t reflect what you actually need.
In this guide, we’ll walk through what makes a casting drawing useful for quoting – and how to avoid the common pitfalls that slow the process down.
Why Accurate Drawings Matter
1. Quoting Accuracy Depends on Engineering Input
A casting quote isn’t just based on weight and volume – it relies heavily on the specifications you provide. If tolerances, material grades, draft angles, or finish requirements are unclear or missing, the quote may not reflect your real needs.
2. Minimising Back-and-Forth with the Foundry
Every round of clarification costs time. Whether it’s asking for missing dimensions or querying CAD compatibility, the more complete your submission is, the faster we can move to pricing and lead time.
Engineering Best Practices for Casting Drawings
1. GD&T Principles
Geometric Dimensioning and Tolerancing (GD&T) principles help ensure we know exactly what level of precision is needed where. Even if every surface doesn’t need tight tolerances, showing where they do helps us cost your part more accurately.
2. File Format Guidelines (STEP, DWG, PDF)
We recommend uploading a STEP file for 3D geometry, a PDF for 2D annotated drawings, and optionally DWG if you’re using AutoCAD. If you only have one file type, make sure it includes all critical details.
For reverse engineering jobs, photos and context help – but drawings make all the difference.
Common Pitfalls to Avoid
1. Missing Dimensions and Tolerances
Too often we receive drawings with no tolerances listed. This leaves us guessing – which may result in over-engineering (and overpricing) your part.
Always specify tolerances for functional features, and note any finish requirements (e.g. machined, as-cast, painted).
2. Overcomplicating Early Stage Designs
Some early-stage CAD models are overly detailed or include features that aren’t casting-friendly (like sharp internal corners). If you’re still in the design phase, ask us to review your drawing before tooling.
Fowler & Holden’s Expertise with Uploaded Drawings
1. Reverse Engineering Options
No drawing?
No problem. We can reverse engineer legacy components using our in-house 3D scanning and inspection tools, creating casting-ready files from worn or broken parts.
2. Pattern and Tooling Advice
Beyond quoting, our engineers advise on pattern design, gating, and risers – ensuring your drawing isn’t just manufacturable, but cost-effective too.
We’re more than a quoting machine. We’re an engineering partner.
FAQs
What is required on a casting drawing for accurate quoting?
At minimum: dimensions, tolerances, material grade, finish requirements, and an indication of volume or batch size.
Do foundries accept hand-drawn or scanned sketches?
Yes, but they may delay quoting. Digital formats like STEP or PDF allow us to start quoting immediately.
What file formats do UK foundries prefer?
STEP (.stp), DWG, and PDF are preferred. We accept most formats as long as critical data is visible.
What are the top mistakes engineers make in casting drawings?
Missing tolerances, unclear materials, non-castable geometries, and omitting finish or machining notes.
Does adding tolerances and finish levels help speed up quotes?
Yes – it reduces follow-up questions and allows us to cost more accurately, saving you time.
Get Started
Use our checklist to make your casting drawings quote-ready
Contact us
Call: +44 (0)1472 355 316
Email: admin@fowlerandholden.co.uk
