Guides · Tolerances · Cost · RFQ
Engineering guides
Practical CNC machining guides for engineers: how to specify tolerances, what drives part cost, how to prepare files for a quote and how to choose a supplier, written by the people who review and quote your drawings.
Most of the cost and most of the delay in a machined part is decided before the first chip is cut: in the tolerance block, the thread callouts, the choice of material and finish, and how clearly the drawing says what matters. These guides collect what we explain most often in the DFM notes that come with every quote.
They are written for mechanical engineers and product teams, with concrete numbers rather than marketing language. Each guide explains the trade-offs, including when a different process or a different kind of supplier would serve you better. Start with tolerances and cost if you are designing a part; start with file preparation if you are about to send an RFQ.
Guides
Design and sourcing guides
CNC machining tolerances
Standard tolerance chart, what machining holds by feature, and how to call out only what matters.
12 cost driversHow much CNC machining costs
Setup, material, machine time, tolerances, finishes and quantity: where the money goes and how to reduce it.
RFQ checklistPreparing CAD files for a quote
STEP vs STL, what the drawing must show, thread callouts and a copy-paste RFQ checklist.
Supplier selectionXometry alternatives
Marketplaces, automated factories, China-based platforms, direct suppliers and local shops compared by model.
Reference
Materials and finishes reference
CNC machining materials
Common metals and plastics, their properties, typical uses and how to choose a grade.
Blast · coat · plateSurface finishes
Bead blasting, anodizing, powder coating, passivation, plating, polishing and laser marking.
Type II · Type IIIAnodizing
Clear, black and colored anodize, hard anodize, masking and how coating thickness affects fits.