CNC Machining Services

Precision CNC Machining

Our in-house CNC machining department provides precision finishing for investment cast parts. With 20+ CNC centers including 3-axis, 4-axis, and 5-axis machines, we achieve tolerances down to ±0.02 mm and surface finishes to Ra 0.8 μm. For cast components with multiple datum relationships, our 4-axis and 5-axis workflows allow multi-face machining in one cycle without repeated repositioning. Fewer setups mean fewer opportunities for accumulated deviation, which is critical for sealing diameters, perpendicularity, and bore-to-flange alignment. This one-clamp strategy helps maintain consistent part geometry from first article to batch production.

20+ CNC machining centers
3-axis, 4-axis, and 5-axis capability
Tolerance down to ±0.02 mm
Surface finish down to Ra 0.8 μm
Maximum part diameter: 800 mm

In-house turning, milling, threading, and facing on cast components

Machining Capabilities

We handle all common machining operations in-house, eliminating the need for secondary suppliers and reducing lead time. Our team routinely machines pressure-bearing details such as NPT and BSP pipe threads with gauge verification to ensure assembly reliability in field conditions. Thread cutting is performed at controlled feed rates—typically 0.8–1.2 mm per revolution for coarse threads—using carbide inserts with TiN coating to maintain dimensional stability across production runs. For valve and pump applications, we control flange face flatness to ≤0.01 mm deviation, groove dimensions within ±0.05 mm, and sealing surface finish to Ra 1.6 μm or better, ensuring mating performance is consistent across production lots.

Our fixture library includes modular tombstones and dedicated soft jaws for repeat valve body families, pneumatic clamps for thin-walled pump housings, and vacuum fixtures for large-diameter flanges. Each fixture is designed to reference as-cast datum features—typically a machined boss or mounting face—so that dimensional relationships established in the casting process are preserved through final machining. This datum continuity is especially important for multi-cavity castings where port-to-port spacing must remain within ±0.10 mm to match customer assembly jigs.

CNC turning & milling
Drilling, tapping, boring
Thread cutting (NPT, BSP, metric)
Face sealing surfaces
Flange bolt patterns
Custom fixture design & manufacturing

Quality Assurance

Every machined part undergoes comprehensive dimensional inspection using calibrated instruments and CMM (Coordinate Measuring Machine) to verify conformance to drawings. Our control plan combines first article inspection with in-process checks at key machining stages, especially before and after operations that establish critical datums. Operators follow documented inspection frequency by feature class, and any drift triggers immediate process adjustment before parts continue downstream.

Our CMM inspection protocol captures 100% of geometric dimensioning and tolerancing (GD&T) callouts, including position, perpendicularity, concentricity, and profile tolerances. For features with ±0.025 mm tolerance bands, we record actual measurements to 0.001 mm resolution, providing statistical evidence of process capability. Surface finish is measured using Mitutoyo contact profilometers at defined sampling intervals, typically 0.8 mm cutoff length for machined cast surfaces. Critical sealing faces receive 100% flatness measurement to verify deviation stays within 0.01 mm across the contact zone.

Equipment	Brand	Capability
CMM	Hexagon	Accuracy ±0.003 mm
Surface Roughness Tester	Mitutoyo	Ra 0.1-12.5 μm
Hardness Tester	TIME	HRC, HRB, HV
Profile Projector	Nikon	50x magnification

For regulated or performance-critical projects, we can provide CPK capability summaries, full-dimensional inspection reports, and traceable measurement records aligned with your PPAP or customer documentation package.

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Integrated casting and CNC machining for precision components

When to Choose In-House Casting + Machining vs Separate Suppliers

Many buyers source rough castings from a foundry and then send them to a separate machine shop for finishing. While this works in principle, the handoff introduces risks: dimensional disagreements between suppliers, tolerance stack-ups across inspection systems, shipping delays, and dual logistics costs.

Choose integrated casting + machining when:

Tighter tolerances matter — ±0.025 mm on critical bores and seal diameters are easier to hold when the same quality system manages both casting and machining
Complex geometries — investment cast features like internal passages and thin walls require machining setups that respect as-cast datum references
Faster time to market — eliminating the supplier handoff saves 1-2 weeks per batch on logistics and re-inspection
Single point of accountability — one vendor owns the entire process from pattern to finished part, reducing dispute resolution time
Volume 50-5,000 parts/year — below this range, separate suppliers may be more economical; above, dedicated machining lines may be justified

Cast-and-machine integration is especially valuable for valve bodies, pump housings, and flanged fittings where sealing surfaces must align perfectly with cast datum planes. Learn more about our investment casting capabilities.

CMM quality inspection for CNC machined cast components

Why Work with Matson for CNC Machining

Our CNC machining department operates under the same quality system as our foundry, creating direct accountability from pattern to finished part. This integration delivers measurable benefits:

Same quality system — ISO 9001:2015 covers both casting and machining, so one set of standards governs your entire part
Engineering-driven setups — our machinists work from the same CAD models as our casting engineers, eliminating interpretation gaps
Flexible capacity — 20+ CNC centers with 3/4/5-axis capability, programmed for rapid changeover between job runs
Inspection-ready parts — every machined part ships with dimensional report, material cert, and surface finish measurement
Export-ready packaging — cleaned, deburred, rust-protected, and packed per your shipping destination requirements

Whether you need a prototype batch or production volumes, our machining team ensures your cast parts meet the specifications your application demands. Submit your inquiry for a CNC machining quote.

From rough casting to finished component, our CNC machining capabilities cover every stage. Learn about our CNC machining capability range, review precision machining tolerance standards, and understand CNC machining quality inspection methods to see how we maintain consistency across production runs.

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Frequently Asked Questions About CNC Machining for Cast Parts

What machining capabilities does Matson Foundry offer?

We operate 3-axis and 4-axis CNC machining centers for turning, milling, drilling, and boring. Our 4-axis capability allows complex geometries like valve ports, pump bores, and multi-angle features to be completed in a single setup, improving accuracy and reducing cycle time.

Can you machine castings from other foundries?

Yes. We accept castings from other foundries for finishing. Each incoming batch is inspected for dimensional conformity and material certification before machining begins.

What tolerances can your CNC machining hold?

Our standard machining tolerance is ±0.05 mm (ISO IT8). For precision features, we hold ±0.025 mm (ISO IT7) on critical bores, seal diameters, and mating surfaces.

Do you offer in-process inspection during machining?

Yes. Our machining process includes in-process dimensional checks, probe-based part verification, and first-article inspection reports. CPK studies are available for high-volume programs.

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