Bowling Green CNC Processing Service

A 5-axis machining center moves the tool and the part at the same time, so it can reach faces that a 3-axis machine cannot see without a second setup. That matters for parts with angled holes, deep pockets on more than one face, or contoured surfaces that meet at a shallow angle. In one setup, the operator can finish five sides instead of three.

Setup count drives both cost and error. Every refixture adds a datum shift, and those shifts stack up on tight-tolerance features. On a part with ±0.005 mm position callouts across two or three faces, a single 5-axis setup is often the only way to hold the drawing without adding a coordinate measuring machine correction loop.

Not every part needs it. A flat bracket, a simple shaft, or a plate with holes drilled from one direction will run faster and cheaper on a 3-axis mill or a lathe. For that geometry, 5-axis spindle time just costs you money.

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  Good fitImpellers, housings with angled ports, medical instruments, and any part with compound angles.
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  Poor fitPrismatic plates, simple turned parts, and features reachable from two directions.
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  Watch the depthDeep cavities still need long, thin tools that deflect. 5-axis does not remove that limit.

Tolerance and finish should match the function of the feature, not the whole part. A bearing bore may need ±0.005 mm and Ra 0.8–1.6 μm. The same part's mounting flange can sit at ±0.05 mm and Ra 3.2 μm all day. Tightening every dimension on a drawing adds cost without adding function, and it makes inspection slower.

On our machines, the working tolerance is ±0.005 mm (±0.0002 in) on features that call for it. Fine finishes reach Ra 0.2–0.8 μm with the right toolpath and cutter; general machined surfaces land at Ra 1.6–3.2 μm. If a drawing asks for Ra 0.2 μm across a large face, expect polishing or a separate finishing operation, not a single pass.

Material behavior sets the practical floor. Aluminium 6061 and 7075 cut cleanly and hold tight numbers well. Stainless 316 and 17-4PH work-hardens, so heavy radial cuts and small depths of cut change the result. Titanium TC4 and Inconel move under heat and need slower feeds and more coolant. Those effects show up in the finish before they show up in the dimension.

The material choice usually comes from the application, but it also decides the machining strategy. Aluminium grades like 6061-T6, 2024, 5083, and 7075 cover most brackets, housings, and heat sinks. They cut fast, take anodizing well, and keep costs down on short runs.

Stainless 303, 304, 316L, 420, 440C, and 17-4PH show up in medical and food-contact parts where corrosion matters. They machine slower and tool wear is higher, so the same geometry costs more than in aluminium. Titanium TA2 and TC4, plus Inconel and magnesium AZ31B or AZ91D, are for weight, heat, or strength demands that aluminium cannot meet.

Plastics are a separate conversation. POM and PEEK hold dimensions well and are common for insulators and wear parts. ABS, PC, and PMMA are easier to cut but move more with temperature. On any plastic part, tell us the service temperature and whether the part will be annealed, because that changes the stock allowance.

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  Aluminium6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, ADC12.
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  Stainless303, 304, 316, 316L, 420, 430, 431, 440C, 17-4PH (SUS630).
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  Steel1018, 1045, 4130, 4140, 4340, A36, and tool steel.
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  Titanium and specialTA1, TA2, TC4 (Ti-6Al-4V), Inconel, magnesium AZ31B / AZ91D.

Many parts leave the machine and go straight into a finish line. Anodizing comes in clear, colour, hardcoat, and conductive types. Electroless nickel, zinc, silver, and gold plating cover conductivity and wear needs. Powder coating and black oxide handle appearance and corrosion. Bead blasting, tumbling, brushing, and polishing set the final texture, and laser marking handles part numbers with a minimum character height of 1.5 mm.

Before the first chip, we check the model and drawing for manufacturability. Thin walls, deep slots, sharp internal corners, and features below the reach of a standard cutter get flagged. You get a DFM note with the quote, so you can decide whether to change the design or accept the cost of a slower toolpath.

Send STEP or native CAD, a 2D drawing with the critical dimensions and datums, the material and finish callouts, and the quantity you expect this year. If tolerances are still open, say which features matter. That one detail speeds up the quote more than anything else. Files stay confidential, and we sign an NDA on request.