Technical Resources
Reference tables we use on the floor, and notes on how machining work actually gets priced. Written by the people who cut the parts — no download required, no email gate.
The Numbers We Look Up Ourselves
These are the three charts our quoting engineers keep open. If you send us a drawing, these are the standards we'll be working to unless you tell us otherwise.
CNC Machining Tolerance Chart
ISO 2768 numeric tables for all four tolerance classes, what each process can realistically hold, every GD&T symbol in one table, and the tolerance-cost curve that decides your quote.
Use it when: a drawing says "ISO 2768-m" with nothing else.
Aluminium Grade Selection Chart
6061, 7075, 5052, 2024, 6063 and 2A12 compared on strength, fatigue life, machinability, weldability, anodising response and cost — plus a seven-step decision tree.
Use it when: you're deciding between 6061 and 7075.
Surface Finish Comparison Chart
Nine finishes side by side — anodising Type II and hardcoat, passivation, black oxide, zinc, electroless nickel, powder coat, bead blast, polishing — with thickness, hardness and salt spray hours.
Use it when: a coating is about to break one of your fits.
Notes on Pricing, Certification and Honest Quotes
What it's actually like to work with this shop, including the parts where we're not the right answer.
We Quoted 5x Their Supplier. We Lost.
A US manufacturer's existing supplier beat us by five times. We dug into why, explained the arithmetic, and told them to stay put. What ten years of process optimisation actually buys.
Why two shops can quote the same drawing five times apart.
Why 40 Parts Cost More Per Piece Than 4,000
Programming, setup and prove-out don't scale with quantity. The full cost breakdown, plus four questions to ask any shop quoting you a small batch.
Why your prototype quote looks nothing like your production price.
We Don't Hold ISO 13485. Here's How Medical Work Happens.
A veterinary device company needed a certificate we don't have. They visited our floor, and we built an arrangement inside their own certified supply chain instead.
How uncertified machining capacity fits under a certified QMS.
Why Source CNC Machining From Shenzhen?
A shop owner's honest take — what the city actually gives you, what it doesn't, and how to vet any Shenzhen supplier in one email.
The case for and against, from someone who works here.
Where We're Not the Right Shop
Three of the pages above are about jobs we didn't win, certificates we don't hold, and prices we couldn't beat. We publish them because the alternative is a website that says "quality, delivery, competitive pricing" — which every machine shop on earth already says.
If you're comparing quotes that don't seem to describe the same part, or you're not sure whether we're the right shop for your application, read those first. Then send us the drawing — we'll tell you straight.
Working to a standard we haven't covered?
Send the drawing and tell us what you need to hold. We'll quote it, or tell you who should.