Why Drawing Revision Matters in Casting RFQs

# Why Drawing Revision Matters in Casting RFQs

Drawing revision control is a small detail that can change a casting quote. When a buyer sends an outdated file, mixed file set, or unclear revision note, the supplier may quote the wrong geometry or carry assumptions that do not match the current design.

For aluminum casting RFQs, this matters because geometry, wall sections, machining stock, hole locations, finish notes, and assembly features can all change between revisions. A supplier does not need a perfect file set to start a discussion, but it does need to know which files are current and which files are only background information.

This guide explains how buyers can manage drawing revisions before sending an RFQ.

Put the revision in the RFQ email or form

Do not rely only on the file name. The RFQ message should state the drawing revision clearly.

For example:

• •part number: BH-1001
• •current drawing revision: Rev C
• •3D model: matches Rev C
• •older Rev B file included only for reference: no

This gives the supplier a clear starting point. If the supplier later asks a question, both sides can refer to the same revision. Bohua's RFQ package route gives buyers a structured place to send this context.

Avoid sending mixed revisions without explanation

Sometimes buyers send a PDF drawing from one revision and a 3D model from another. This can happen during engineering changes or when file systems are not fully updated.

If the files do not match, say so directly. A clear note is better than silence:

The 3D model is newer than the PDF drawing. Please use the model for geometry review and the drawing for general notes only. A matched drawing set will follow.

This type of note helps the supplier avoid treating the two files as fully aligned.

Identify what changed

If the supplier is reviewing a revised quote, it helps to summarize what changed. The buyer does not need to write a full engineering report. A short change list is enough.

Useful change notes include:

• •wall section changed near a boss
• •hole location updated
• •mounting face changed
• •surface note revised
• •thread depth changed
• •weight target changed
• •part number stayed the same but revision changed

This helps the supplier focus review time on the features that may affect the quote.

Separate quote revision from drawing revision

A quote can be revised even when the drawing does not change. A drawing can change even when the buyer has not requested a new quote yet.

Keep the two revision systems separate:

• •drawing revision: controlled by engineering design
• •quote revision: controlled by commercial and supplier assumptions

When asking for an updated quote, state whether the drawing changed or only the quotation basis changed. This avoids unnecessary technical review when the only change is quantity, finish scope, packaging, or delivery terms.

Ask suppliers to quote with the revision shown

Buyers should ask suppliers to state the drawing revision in the quote. This creates a simple trace between the RFQ package and the supplier response.

A quote assumption line can be simple:

Quote based on part number BH-1001, drawing Rev C, PDF dated May 2026, STEP file received with RFQ.

This small note can prevent confusion later if a new revision appears before tooling or production approval.

Use a file list for multi-part RFQs

When an RFQ includes multiple part numbers, use a file list. The file list should show each part number, drawing revision, model file, and open status.

Example columns:

• •part number
• •part name
• •drawing file name
• •drawing revision
• •model file name
• •model revision if available
• •current or reference file
• •notes

This table helps the supplier confirm that every part was reviewed from the right file set. For more file-preparation detail, see the casting drawing requirements resource.

Flag design freeze status

The supplier should know whether the drawing is released, nearly final, or still changing. This does not need to be complicated.

Use a simple status:

• •released for quote
• •under supplier review
• •preliminary
• •revision expected
• •replacement sourcing from existing part

If the design is still changing, the supplier can quote with that context. If the drawing is released, the supplier can treat it as a stronger basis for review.

Keep old files out unless they are needed

Old files can be useful, but they can also create confusion. If an old drawing or model is not needed, do not include it. If it is needed for background, mark it clearly as reference only.

A supplier should not have to guess which file controls the quote.

Update the RFQ when the revision changes

If the buyer changes the drawing after the quote is requested, send an update. The update should state whether the supplier needs to re-quote or only keep the new revision on file.

Useful update language:

Drawing revision changed from Rev C to Rev D. Please review whether this changes the quote basis. The main change is the mounting face note on sheet 2.

This keeps the supplier response tied to the latest engineering intent.

Bottom line

Drawing revision control is not paperwork. It is part of quote quality. A clear revision note helps the supplier quote the correct geometry, list assumptions, and respond with fewer back-and-forth questions.

Before sending an aluminum casting RFQ, confirm the current drawing revision, match the model and drawing when possible, explain any mismatches, and ask the supplier to state the revision in the quote.

If you are preparing a revised casting RFQ, Bohua can review the drawing package and help identify which assumptions should be listed before quotation. Send the current revision, any reference files, and a short change note through the RFQ form.

FAQ

Can I request a quote before the drawing is final?

Yes. State that the drawing is preliminary or under review, and ask the supplier to list assumptions in the quote.

What if the PDF and 3D model do not match?

Say which file controls geometry and which file is for reference. If neither is final, state that a matched file set will follow.

Should the supplier state the drawing revision in the quote?

Yes. The quote should identify the part number, drawing revision, and file basis so both sides know what was reviewed.

What should I send when a revision changes?

Send the new file, identify the old and new revision, summarize the main changes, and ask whether the quote basis needs to be updated.