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Free DFM Review — Before You Pay for the Part

Send a drawing. Within 16 hours Bill, our engineering manager, sends back a quote and the two or three changes that would make the part cheaper, faster or easier to hold in tolerance. No charge, no obligation, and the files stay in the shop.

Why we do this

An auto-quote prices your drawing. An engineer questions it.

Online platforms price whatever you upload. They will never tell you that a ±0.01 mm on a clearance hole is doubling the cost, or that a 0.5 mm internal corner is forcing a tool change nobody needs. A 36-person shop cannot compete on volume, so we compete on the thing an algorithm cannot do: read the drawing and tell you what it is really asking for.

What is driving the cost

The two or three callouts that account for most of the price, and what each one would save if relaxed. You decide; we do not change your drawing.

What will be hard to hold

Features we expect to struggle with — thin walls that will move, deep pockets, fits that need a gauge — flagged before the order, not on the first article.

A quote that reflects both

Price and lead time for the part as drawn, and, where it makes sense, an alternative price for the part with the suggested changes.

What we look at

The seven things that decide what a machined part costs

Almost every expensive part is expensive for one of these reasons. The examples are typical of what we see, not promises for your part — your numbers come with your quote.

1. Tolerances

Every extra decimal place costs machine time and inspection time. A ±0.005 mm where ±0.05 mm would work can add 30–50% to a feature. We ask which dimensions are actually functional.

2. Number of setups

Each time the part is re-clamped it costs handling and risks stacking error. Thirteen of our 32 centres are four-axis, and a part designed so we can reach it in one setup is usually the cheapest version of itself.

3. Internal corner radius

An internal corner smaller than the cutter forces a smaller cutter, slower feeds or an EDM operation. Going from R0.5 to R1.0 on a pocket often removes a tool change entirely.

4. Deep pockets and thin walls

Depth over four times cutter diameter means slow cutting and deflection; walls under 1 mm move when clamped. Both are machinable — both cost more than the drawing suggests.

5. Material

6061 cuts three times faster than 316L and holds tolerance more easily. If the drawing says stainless for appearance rather than corrosion, anodised aluminium may do the job at a fraction of the machining time.

6. Surface finish and coating

Ra 0.8 µm costs more than Ra 1.6 µm; hard anodise costs more than clear. A finish specified over the whole part, when only one face matters, is paid for on every face.

7. Quantity and price breaks

The setup is the cost. Between 10 and 100 pieces the price per part often halves. Ask for two or three quantities and we quote them all — sometimes a slightly larger run is cheaper in total.

And the one people forget: inspection

A drawing with fifty toleranced dimensions takes fifty measurements on the CMM. Tell us which are critical and we inspect those to the letter and the rest to ISO 2768-mK.

What it looks like

A DFM note is short, specific and about your part

This is the shape of what comes back. The values are illustrative — a real note refers to your dimensions, your material and your quantity.

Aluminium block with bored ID and milled slots, machined in one setup on a four-axis centre
Machined in one setup after DFM
Example — aluminium housing, 50 pcs

Three notes, one alternative price

  • Pocket corner radiusR0.5 → R1.0, removes one tool change
  • Bore toleranceH7 kept; H6 on the second bore relaxed to H7 — not a bearing seat
  • Wall thickness1.0 mm → 1.5 mm on the back wall, avoids deflection and a remake risk
  • FinishClear anodise on visible faces only, back face as-machined
  • Result, as drawnQuoted at 100%
  • Result, with changesQuoted at roughly 70%, one day shorter lead time

You accept some, all or none of the notes. The drawing is yours; we only tell you what we see.

How to send it

What to include so the review is useful

A 3D file and a 2D drawing

STEP, IGES or X_T for geometry; PDF, DWG or DXF for tolerances, threads, material and finish. Both together is fastest. One is fine to start.

Which dimensions are critical

A sentence is enough: “the two Ø20 bores are bearing seats, everything else is clearance”. It changes the quote more than anything else.

Quantity and when you need it

Now, and roughly per year if it repeats. Two or three quantities get two or three prices.

What the part does

Not the whole project — just enough that we do not suggest a change that breaks the function.

No CAD? Send what you have

A sketch with dimensions, or the worn part itself. We measure, draw and send you the drawing to approve before cutting.

NDA first if you prefer

Send yours or ask for ours. Files are seen by the engineer who quotes them and the programmer who runs them, nobody else.

Questions

Before you send it

Is it really free, and what is the catch?
It is free, and the catch is the obvious one: we would like to make the part. If the notes are useful and the quote is fair, you order. If not, you keep the notes and owe us nothing. Nobody chases you.
Will you change my design?
No. We tell you what we see and what it would save; you decide. If you want us to redraw a feature we will do that on your instruction, and the revised drawing is yours.
What if the part is fine as drawn?
Then the note says so, and you get a quote. Not every drawing needs changing. A short note that says “no changes recommended” is still worth having before you commit a purchase order.
How fast?
Within 16 hours, usually the same working day. Complex assemblies with many parts may take a day longer; we will tell you when we open the files.
Do you keep my files?
Only for as long as we need them to quote and, if you order, to make the parts and repeat them later. They are not shared with other suppliers and never appear on this site without your written permission.

Send the drawing. You get a quote and the notes in 16 hours.

STEP, IGES, X_T, DWG, DXF or PDF. Metric or inch. No minimum order, no obligation.

Send it here

Upload the drawing for review

Attach the 3D file and the 2D drawing together if you can, and tell us which dimensions matter.

Phone / WhatsApp / WeChat
Who reads it
Bill, Engineering Manager — every drawing, before it is priced
Hours
Mon–Sat 08:00–23:00 China time

    Your files are covered by our NDA and are only seen by our engineering team.

    Your files are used to quote and make your parts, nothing else.

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