RESOURCES
Practical notes from machining, inspection and real production requirements at VietTech.
Technical resources for engineers and buyers reviewing CAD data, materials, tolerances, machining processes and inspection requirements.
69 technical articles
Understand why an in-tolerance reading may need further review, how guard bands work and what to agree before accepting precision-machined parts.
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69Understand why an in-tolerance reading may need further review, how guard bands work and what to agree before accepting precision-machined parts.
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Separate controlled shot peening from cleaning blasts, distinguish intensity from coverage and specify treatment zones and evidence correctly in an RFQ.
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Understand radial engagement, chip thickness and feed per tooth, then check CAM compensation to avoid double adjustment and excessive corner loading.
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Choose a PEEK grade by stiffness, mating surfaces, electrical function and stock orientation, rather than assuming reinforcement improves every property.
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Understand steel surface decarburization, distinguish it from oxide scale, and define inspection, machining allowance and RFQ requirements after heat treatment.
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Define the FAI package in a CNC RFQ: representative samples, ballooned drawings, measurement results, certificates, review responsibilities and release conditions.
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A practical comparison of SCM415 and SCM420 covering carbon range, core response, carburizing, distortion, grinding allowance and RFQ requirements.
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Understand capability versus performance, stability, sampling, measurement systems and how to specify a Cpk requirement in a CNC RFQ.
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How to specify MIL-DTL-5541 without confusing chemistry type with performance class, including electrical contact, painting, masking and records.
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Practical DFM for external threads: pre-turn diameter, insert profile, infeed, relief, burrs and inspection to the applicable thread standard.
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A practical comparison of NAK55 and NAK80 for machining, mirror polishing, EDM finish, toughness and RFQ preparation without treating the grades as automatic substitutes.
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How to use ISO 2768 without obscuring functional dimensions, datums, GD&T or the October 2026 standards transition.
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A DFM guide to selecting internal radii around cutter size, pocket depth, mating parts, inspection, and alternatives for square-corner functions.
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Plan and interpret a Gauge R&R study for CNC-part measurements without confusing it with calibration or measurement uncertainty.
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Compare H900, H1025 and H1150 conditions for SUS630 precipitation-hardening stainless steel, including properties, machining sequence, heat treatment and inspection.
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Specify blind threaded holes without confusing drill-tip depth, tool travel and the usable full-thread length required by the assembly.
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Learn how bored soft jaws, contact diameter, grip length and clamping force affect runout and distortion in finish turning.
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Understand hydrogen entry during cleaning and plating, the difference between stress relief and post-coating baking, and what a CNC RFQ should specify.
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Compare SUJ2 and SUS440C by rolling contact, corrosion, heat treatment, machining and grinding before specifying a wear-resistant precision part.
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Understand why warm parts or different materials measure differently, how to plan thermal stabilization and what to state in a precision-machining RFQ.
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How to anticipate, reduce and inspect burrs at through holes, intersecting bores, threads and tool-exit edges—and specify the requirement in an RFQ.
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Understand MTCs, CoCs, test reports and lot traceability, then state the required material documentation correctly in a CNC machining RFQ.
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Compare POM and PEEK for machined components by operating temperature, dimensional stability, process considerations and material cost.
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Learn how drawing datums, stable fixturing and part-coordinate alignment affect CMM inspection results.
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Learn how to specify induction hardening depth, surface hardness, hardened zones, grinding allowance and inspection for CNC-machined parts.
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Learn how QPQ treatment works, its compound and diffusion layers, wear and corrosion performance, dimensional effects, inspection, and RFQ requirements.
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Compare cut tapping, form tapping, and CNC thread milling by material, blind-hole conditions, chips, torque, accuracy, inspection, and cost.
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Learn how to define governing data when 2D drawings and 3D models differ, including revision control, tolerances, notes, inspection, and RFQ packaging.
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Compare SUS304 and SUS316 for corrosion resistance, CNC machining, welding, surface finish and RFQ requirements for precision components.
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Understand roundness and cylindricity tolerance zones, how they differ from size and runout, and when to use an indicator, roundness tester, or CMM.
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Learn what causes heat-treatment distortion and how machining allowance, process planning, finish grinding, and inspection help maintain part accuracy.
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Learn how straightness and flatness differ, how their tolerance zones work, and when to use a surface plate, indicator, or CMM for inspection.
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Compare 5052 and 6061 aluminum for strength, forming, welding, CNC machining, dimensional stability, and anodizing before selecting a part material.
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Compare SKD11 and SKD61 by operating temperature, hardness, wear resistance, toughness, heat treatment, and precision-machining requirements.
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Learn how perpendicularity and angularity tolerances differ, how to interpret datum references and tolerance zones, and how to inspect them with a CMM.
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Compare climb and conventional milling by chip formation, cutting-force direction, surface finish, backlash, and workholding to select a stable CNC process.
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Compare glass bead and aluminum oxide blasting for cleaning, satin finishing, surface profiling, dimensional control, masking, and RFQ specifications.
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Learn why steel is tempered after hardening, how grade-specific tempering conditions are selected, when to measure hardness, and how to plan grinding allowance.
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SUS303 and SUS304 are austenitic stainless steels commonly specified for shafts, bushings, fittings, brackets, housings and equipment components. Their app
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A practical guide to opening a 2D DWG in the browser, understanding the first-use delay and checking rendering limits before quotation.
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Compare DWG and DXF for file size, data exchange, fonts, CAD objects and manufacturing communication.
READ ARTICLE ↗What normally survives conversion, what can change and a practical post-conversion checklist.
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Learn how to interpret surface profile tolerance, establish the datum reference frame, use nominal CAD data, and plan reliable CMM inspection.
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Compare Type II and Type III anodizing for CNC aluminum parts, including coating thickness, color, wear resistance, masking, and tolerance effects.
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Learn when to stress relieve a part after rough machining, how to plan the process sequence, retain machining allowance, and control distortion before finishing.
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Compare C1100 and C3604 by electrical conductivity, machinability, strength, application, inspection, and RFQ requirements.
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Learn how to plan deep pocket CNC milling through tool reach, stable entry, layered roughing, chip evacuation, uniform allowance, finishing, and inspection.
READ ARTICLE ↗Learn how to interpret hole-pattern position tolerance, datum reference frames, basic dimensions, MMC, bonus tolerance, and inspection methods.
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Compare passivation and electropolishing for stainless steel, including material removal, roughness, appearance, corrosion performance, and tolerances.
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Understand how hardening and tempering balance hardness, toughness, residual stress, distortion, and finish-machining requirements for precision parts.
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Learn how work support, cutting forces, heat, and process sequence affect chatter, taper, straightness, and runout in CNC turning of slender shafts.
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Compare POM and cast nylon for dimensional stability, moisture absorption, friction, wear, and CNC machinability to select the right plastic.
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6061 and 7075 are widely used for CNC-machined components, but they are not interchangeable based on appearance or weight alone. 6061 is commonly selected
READ ARTICLE ↗A practical comparison of four common CAD formats for drawing review, quotation and manufacturing communication.
READ ARTICLE ↗A short review reduces revision mistakes, missing units and avoidable clarification cycles.
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Why DWG/DXF text becomes question marks or displaced notes, and how to prepare files for more consistent rendering.
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A hole on an engineering drawing is rarely defined by diameter alone. Its function may also depend on position to datums, perpendicularity, cylindricity, s
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Learn the difference between circular and total runout, how datum setup affects results, and how to inspect precision rotating components.
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Compare electroless nickel and hard chrome by coating uniformity, wear, corrosion, machining allowance and final inspection.
READ ARTICLE ↗Compare vacuum and induction hardening by hardened zone, core properties, distortion, surface condition and finish-machining requirements.
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Practical considerations for milling thin-wall housings and plates: stock, sequence, workholding, tooling and inspection after unclamping.
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Compare black oxide and zinc plating by corrosion protection, dimensional effect, appearance, threads, material condition and RFQ requirements.
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Nitriding and carburizing are thermochemical treatments used to produce a wear-resistant surface while retaining suitable core properties. They are often s
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Surface roughness can affect friction, sealing, fatigue behaviour, fit stability and appearance. Ra is widely used on mechanical drawings to describe the a
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S45C and SCM440 are commonly specified for shafts, pins, blocks, plates, fixtures and machine components. They should not, however, be treated as interchan
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A practical guide to wire EDM principles, suitable profiles, inside-corner limits and the information needed for an accurate machining quotation.
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A practical guide to surface and cylindrical grinding after heat treatment, including grinding allowance, distortion and drawing requirements.
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Flatness and parallelism both constrain surfaces, but differ in datum reference, function and inspection. A clear distinction supports a more accurate machining RFQ.
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A practical guide for engineers and buyers preparing material, heat-treatment and surface-finish requirements for a machining quotation.
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