CNC Machining FAQ — Quotes, Tolerances & Lead Times

Quotes, pricing and MOQ

This is the hub for the questions we get before and during an order — what to send, what it costs, how long it takes, what travels with the goods and what happens if something is not right. Each answer links to the detailed page where the subject is covered properly.

How do I get a quote?

Send your drawing — STEP, IGES, DWG, DXF or PDF — through the quote form or WhatsApp. We return DFM feedback and a price within 24 hours, on business days.

How is a machined part priced — what am I actually paying for?

Six things: the material and how much of it is cut away, the machine time the geometry needs, the number of setups and how many parts share each one, any secondary operations such as tapping or heat treatment, the surface finish, and the packaging. Two quotes for the same part normally differ because those six are not the same, not because one supplier is cheaper.

What is the minimum order quantity (MOQ)?

From 50 pieces per style and material. A production run builds on the same setup as the sample batch, so the two are not separate jobs.

Do you charge for quotes or samples?

Quotes are free and come with DFM feedback. Sample pricing depends on the part, the quantity and the material, and is stated as its own line on the quote so you can see what it costs.

What if the part is a repeat order?

Say so at the quote stage and the price changes shape. The first batch carries the programming, the setup and the tooling, and a repeating part spreads that over the volumes you expect. Give us the first quantity you would order and the annual volume if the part repeats, and the quotation is built around the part being made more than once rather than as a one-off. The details of how repetition changes unit price are on bulk order pricing.

What are your payment terms?

The terms are stated on the quotation rather than quoted as a standing policy, because they depend on the order — how much of it is custom material or tooling committed ahead of production, and whether we have supplied you before. Where a deposit applies, it is because material or tooling has to be ordered before the first part can be cut. Ask at the quote stage and the terms come with the price.

Files and drawings

What to send, what to avoid, and what happens when the file is the problem.

Which file format is best for a machined part?

A STEP file plus a PDF drawing. The STEP carries the geometry and works whether the part is modelled in SolidWorks, Fusion, Inventor, NX or Creo. The PDF carries what the model cannot: which dimensions are toleranced, which surfaces matter, the thread callouts, the finish, and the material. Send both and nothing gets assumed.

What file formats do you accept?

STEP, IGES, DWG, DXF, PDF, and native SolidWorks or Fusion files. If your CAD package exports a neutral format, that is enough.

Can I send an STL file?

You can, but it is a poor fit for machining. An STL describes a surface as a mesh of triangles rather than as precise geometry, so there are no true cylinders, no sharp edges and no exact dimensions to work from. We will look at one to understand what you are describing, but a STEP or a dimensioned PDF is what we need before a quote.

Can you quote from a PDF or a sketch?

Yes. A dimensioned PDF is enough to start. A 3D model plus a PDF answers most questions up front and shortens the back-and-forth. See drawing and file requirements for what a drawing needs to carry.

What if I have no CAD file at all?

Send a sketch with the dimensions that matter, or a photograph with a ruler in it, and say what the part has to do. We will come back with what is missing. For a simple part that is usually a short list — overall size, hole positions, thread and material. A design service step can also turn a description into a drawing before quoting.

What are the most common file problems you see?

Four. A drawing whose general tolerance block is missing or names no class. Thread callouts without a thread class. Tolerances stated on features that do not need them, which raises the price without changing the part. And a model that has been revised without the drawing being revised with it. All four are visible at the quote stage, which is why the DFM feedback comes before the price.

Can you send me a STEP or DXF of my part?

We quote from your geometry; we do not redistribute it. Where a part is modified during DFM, the change is described and shown so you can update your own model and drawing, and your revision stays the master. If you need a specific export for your own records, say so at the quote stage.

Can you reverse-engineer a part from a sample?

Yes. A physical sample is one of the inputs we work from, alongside a drawing, a 3D model, a dimensioned sketch or a photograph. Where a part has no drawing — an old component, a discontinued item, a part that has to be reproduced because the original supplier has gone — the sample is measured and the geometry is turned back into a model and a drawing you can hold. Say what the part has to do as well as what it measures, because a reproduced part that fits but does not function has not solved the problem. See design and DFM support.

Lead times and samples

Production timing, and how a first order is de-risked.

What is the sample lead time?

5 to 10 days after the drawing is approved, depending on the part and the material.

What is the production lead time?

25 to 35 days after the sample or the drawing is approved, depending on quantity and finish. Surface work and heat treatment are the two steps most likely to push it.

Can you expedite an order?

We look at each request against the schedule. A rush is far more likely to work when the drawing, the material and the finish are settled up front, because the schedule then only moves production rather than waiting on answers.

Can I order a sample first?

Yes, and for a first order it is worth it. A sample from a single piece lets you check fit, function, finish and packaging before a 50-piece run is cut. See how to order.

Can I supply my own material?

Yes. Free-issue stock is machined, the balance is returned or accounted for, and the material test report obligation stays with your supplier rather than moving to us. Send the grade, the form and the condition with the drawing, and the quotation prices the machining separately from the material. See the materials page for how free-issue is handled.

Materials

Grades we run, how material is sourced, and the limits of the list.

What materials do you machine?

Aluminium, stainless steel, carbon and alloy steel, tool steel, brass, copper, bronze, titanium and engineering plastics. The grades we run most are 6061 and 7075 aluminium, 303, 304 and 316 stainless, and 1045 and 4140 steel. The full grade list sits on the materials page.

Can you supply the raw material?

Yes. We source to your specification and ship a material test report (MTR) with every order, tracing the grade to the mill heat it came from.

Which stainless steel grades do you machine?

301, 303, 304, 304L, 316, 316L, 410, 416 and 17-4PH, matched to what the drawing calls for. 303 and 416 are the free-machining grades; 304 and 316 are the corrosion grades; 17-4PH is the one that adds strength after ageing. See stainless steel parts.

Which aluminium alloys do you machine?

2024, 5052, 6061 and 7075. 6061 is the general-purpose choice, 7075 is the high-strength one, 2024 is the aerospace-grade one and 5052 is the formable one. See aluminium parts.

What material specification will you use, and can I see it?

The one on your drawing, and yes — the material test report (MTR) accompanies the order and names the grade, the heat and the standard it was bought to. If your drawing names a grade without a standard, we will say which standard we are sourcing to before the order is placed rather than after.

Does material grain direction matter?

On some parts, and it is worth a line on the drawing when it does. Rolled bar and plate have a direction, and a part machined across the grain behaves differently from one machined along it — a thin rib or a long slender feature can distort or be weaker one way round. Where it matters, mark the grain direction on the drawing. Where it does not, say nothing and the part will be nested for the best material yield.

Tolerances and precision

What the drawing controls, and what the process controls.

What is your general tolerance?

ISO 2768-m for dimensions the drawing does not call out. If your drawing carries its own general tolerance block, that block wins. What the note does and does not cover is set out in the ISO 2768-m tolerance chart.

What precision tolerance can you hold?

Plus or minus 0.01 mm on the features your drawing requires, applied feature by feature rather than as a blanket claim. Precision is a decision about which features need it — the details are on the tolerances page.

What does reviewed against your drawing mean?

It means no dimension is assumed. Anything we have not confirmed is checked against your file and quoted from it, and where a feature cannot be made as drawn we tell you before the price rather than after.

How do I call out a surface roughness (Ra) on a drawing?

Put the Ra value on the surfaces that need it, with the symbol and a number — Ra 1.6 is a common machined finish. Leave the rest to a general note, such as leaving the general surface as machined. Ra is a process signature: a turning operation, a milling operation and a ground surface each land in a different band, so the value you write should be the one the function needs, not the tightest one you have seen.

Can you machine to a fit — bearing seats, press fits, spigots?

Yes, and those features need their own tolerances rather than the general block. A fit is defined by a tolerance band on both parts, so a bearing seat, a press fit or a locating spigot should carry the fit it has to achieve. General tolerances are for the dimensions that do not matter; the tolerances page sets out how the two work together.

How do you hold a deep pocket or a long bore?

With the right tool and a plan, not with a single pass. A deep pocket is taken in steps with a tool long enough to reach but stiff enough to cut, and a long bore is drilled undersize and then finished by boring, reaming or interpolating with an end mill. A hole produced by drilling alone is a roughing operation: the twist drill cuts oversize, and drilling deeper than about three times the diameter needs pecking to clear chips. The size a drill actually produces is set out in the drill size chart.

Which thread systems and fits do you machine?

Metric threads, unified inch threads including UNC and UNF, pipe threads including BSP and NPT, and threaded inserts where the drawing calls for them. Threads are governed by their designation and its class, not by the general tolerance block, so the full callout matters — the differences between the systems are set out on thread standards. On fits: a bore, seat or spigot that has to accept another part carries its own fit designation and is machined to that, held to plus or minus 0.01 mm where the drawing requires it. See tolerances.

Surface finish and appearance

What the finish does to the part, and how to state what you need to see.

What surface finishes do you offer?

Anodizing, plating, black oxide, passivation and more, listed on the surface finishes page.

Do you finish in-house?

Finishing runs through our vetted partner network, managed under one quality process, so the surface work stays traceable to your order. Machining itself is done in our own factory in Qidong City, Jiangsu Province, China.

How do I specify a surface finish?

Name the finish, name the area it applies to, and note the roughness if it matters to the assembly. Where a finish is cosmetic on one face and functional on another, say which is which.

How thick is the finish, and does it change my dimensions?

It does, and on a toleranced feature it matters. Anodic coatings and plated layers add material to the surface, so a bore that has to accept a shaft, or a thread that has to accept a fastener, should be considered with the coating in mind. Where a finish sits on a fitted surface, say so on the drawing and we will allow for it — masking the feature is usually simpler than tolerancing around the coating.

What appearance standard can you hold — will there be scratches?

A machined surface carries the marks of the process that made it, and what counts as acceptable depends on where the part is seen. Where a face is cosmetic, say so and it will be handled and packed accordingly. Where the part is functional and the faces are internal, the as-machined surface is the normal result. Where appearance is the requirement, the clearest brief is a photograph or a sample of what you will accept.

Our factory and our partners

Which work is ours, which is not, and where the line sits.

Which processes run in your own factory?

Machining does — milling, turning, Swiss-type work and the secondary operations that follow, in our factory in Qidong City, Jiangsu Province, China. Milling envelopes run up to 800 by 500 mm, and monthly capacity is over 100,000 parts. See our factory and the equipment list.

Which parts of the job go to partners?

Surface finishing, heat treatment and the processes outside machining that a job needs. Plastic moulding runs through our vetted partner network, managed under one quality process, while metal inserts and machined features are done on our own floor. The order, the traceability and the shipping stay with us either way.

Do you make assemblies, or single parts?

Machined parts, and machined parts that go together. A job can include several part numbers that fit as an assembly, with the packing list breaking down each carton, and the secondary operations that turn a machined blank into a finished component — tapping, threading, pressing in threaded inserts, heat treatment and marking.

What is outside your scope?

Worth stating plainly. We machine and finish parts; we do not build electronic assemblies, we do not hold blanket certification across a catalogue, and we do not stock every grade — material is sourced to the specification on your drawing. Where a job needs a process outside machining, finishing and the sheet-metal and moulding work we manage, we will say so at the quote stage rather than take it on. The capabilities page lists what we do run.

Quality documents and traceability

What travels with the parts, and what can be added on request.

What documents ship with my order?

A material test report (MTR) for the raw material, pre-shipment photographs of the finished parts, and the packing list with the carton markings. See quality documents.

Will I see the parts before they ship?

Yes. Photographs of the finished parts are taken before the carton is closed and dispatched, so anything that does not match is corrected on the floor rather than after it has travelled.

Do you send a material certificate?

Yes — a material test report (MTR) accompanies every order, from a 50-piece pilot to a full production run, tracing the grade to the mill heat.

Can I get a dimensional report?

On request, when the drawing identifies the features that matter. The measurements are taken and recorded against the drawing revision the parts were made to, and issued with the order. It is worth asking for at the quote stage so it is planned into the job rather than added to it.

Can you mark or serialize the parts?

Yes. Parts can be laser marked or engraved with a part number, a revision, a date or lot code, a customer mark, or a serial number where each piece has to be individually identified. Marking is a finishing operation like any other, so it is quoted as its own line and shown on the drawing — say where the mark goes and what it has to say, and whether it has to remain legible after the part is finished. See laser marking.

Order progress and shipping

Where the order is, and how it arrives.

How do I check the progress of my order?

Message us on WhatsApp or reply to the quote thread and we will come back with where the job is — material received, machining, finishing, packing. Where a job has a fixed date you need to hit, say so at the start and it is planned around rather than reported on afterwards.

What shipping terms do you work on?

Sea or air, FOB or CIF as agreed. The terms and the port are stated on the quotation, and the packing list follows the carton markings so the goods can be checked on arrival. See packaging and shipping.

How is the part packed?

To suit the part and the journey. Machined surfaces are protected, parts are separated so they cannot rub, and the cartons carry the markings on the packing list. Where a part is going straight to a line or to a retailer, say so — the packing can be built around that rather than around a bulk shipment.

Can you ship to more than one address?

Yes. Several part numbers and several destinations can be handled on one order, with the packing list breaking down what went into each carton. Give us the split at the quote stage so it is priced in.

Can you kit and label the parts separately?

Yes. Where an order carries several part numbers, they can be kept separate, marked and packed so each carton can be checked against its own line on the packing list rather than against the order as a whole. Send the split you need — what goes together, what has to travel apart, and how each carton should be identified — at the quote stage, and the packing is built around it. See packaging and shipping.

If something is not right

What to do when the parts and the drawing disagree.

What if the parts do not match the drawing?

Tell us with photographs and the measurement that is out, and the drawing revision the parts were made to. We compare it against the approved sample and that revision, and come back with what we propose. The fastest route is a picture of the part next to the dimension you are measuring, because it removes the first two rounds of questions.

What if I find a problem after delivery?

Report it as soon as it is found rather than at the end of a production run. Say how many pieces are affected and what the effect is. Where the parts were made to an approved sample and a revision, the comparison is quick.

Who do I contact, and how fast do you respond?

The same person who quoted the job, on WhatsApp or by reply to the quote thread. That is deliberate: the person who priced it already has the drawing, the revision and the sample in front of them, so nothing has to be explained twice.

Ordering step by step

The sequence from a drawing to a delivered carton.

How do I place an order?

Send your drawing, take the quote and the DFM feedback, then we machine the sample and the production batch. See how to order.

How do you handle drawing revisions?

You send the updated file and we re-quote the features that changed, keeping the approved geometry unchanged. The revision you send stays the master, so a part is only ever made to one revision at a time.

Can I combine different parts in one shipment?

Yes. Several part numbers can be machined and shipped together, with the packing list breaking down each carton so the goods can be counted on arrival.

What happens between placing the order and shipment?

A fixed sequence: brief, shortlist and quotation, artwork or drawing confirmation, sample, bulk production, pre-shipment photographs, then dispatch. The sample is the gate — production runs to the approved sample, which is why a first order is worth sampling.

What to send with your request

A job can start without any of this. What each missing item costs is a round trip, and the round trips are what turn a two-day quotation into a two-week one.

• The geometry — a STEP or IGES model, or a DWG or DXF where the part is 2D
• A drawing — PDF, dimensioned, carrying the tolerances, the thread callouts and the surface finish. Where the model and the drawing disagree, the drawing is what we ask about
• Quantity — the first quantity you would order, and the annual volume if the part repeats
• Material and condition — the grade, and the temper or condition where it is specified. If you are supplying the material yourself, send the same detail
• Finish and heat treatment — what is specified and which surfaces it applies to, plus any feature that has to be masked
• Marking — what has to be marked, where it goes, and whether it has to survive the finish
• The documents you need with the goods — a material test report (MTR), pre-shipment photographs, or a dimensional report against named features
• What the part does — the assembly it goes into and the features that have to work. This is the most useful line on a request, because it tells us which tolerances matter and which are costing money for nothing
• Destination and timing — the ship-to address or addresses, and the date the goods have to arrive rather than the date you would like them

A model and a drawing are enough to quote; the rest sharpens the price. Send them through the quote form and the reply comes back within 24 hours with DFM feedback alongside it.