Overview
XCM CNC controls zinc machining cost by grading tolerances, combining operations, and separating roughness targets by function instead of reducing process quality. With ISO 9001 and IATF 16949 aligned systems, imported machines such as DMG and Mazak work together with domestic machining centers so different precision levels can use the right equipment.
Standard +/-0.03 mm tolerance and Ra 3.2 um milled finish stay inside the base quotation, while functional faces and precision bores are handled separately when the drawing requires tighter control. MOQ starts from 1 piece, standard lead time is usually 10-15 days, and the route is suited to die-cast follow-up machining where cost matters but assembly fit and appearance still need to be protected.
Cheap cnc machining services from a direct factory supplier. 
Key Capabilities
Machining Parameters
- Materials: Zamak 3, Zamak 5, Zamak 8 by drawing review
- Tolerance: +/-0.003 mm (+/-0.00012 inch), IT5 or IT6 accuracy, +/-0.01 mm shaft and bore fits, with h6 and H7 available
- Surface Finish: Ra 3.2 um milled, Ra 1.6 um precision, Ra 0.8 um turned or bored
- GD&T: Coaxiality 0.012 mm, runout 0.01 mm, cylindricity 0.011 mm
- Max Size: Milling 3000 x 1600 x 1400 mm, turning diameter 1250 x 2000 mm
- Surface Treatment: Plating, powder coating, chromate finish, painting, or cosmetic prep by drawing review
- Thread: M1.4-M220, NPT, BSP, G, PT
- Cost Note: Standard +/-0.03 mm and Ra 3.2 um are included in the base machining cost, while tighter targets are priced separately
Standard Tolerance Included in Base Machining Cost
Zinc machining includes +/-0.03 mm dimensional tolerance and Ra 3.2 um milled finish in the base route without extra charges. Functional fit holes that need H7 class or 0.015 mm position tolerance are priced as precision features, while non-fit outer geometry can stay on the standard route instead of forcing full-part tight tolerance.
Surface Roughness Zoning to Reduce Finishing Time
Zinc parts can keep Ra 3.2 um on non-critical faces while applying Ra 1.6 um or Ra 0.8 um only to mating bores and functional surfaces. That removes unnecessary finishing time from visible but non-critical faces and keeps the effort focused on the areas that affect assembly or coating quality.
Process Consolidation for Small-Batch Cost Control
Zinc small-batch parts can combine milling, boring, tapping, and deburring into fewer setups to reduce handling time and fixture cost. On thin-wall housings, combining fit-surface milling and hole boring in one controlled setup also helps keep position more stable while lowering unit cost.
Functional-Zone Surface Treatment to Avoid Over-Finishing
Zinc parts can limit plating or cosmetic preparation to mating faces, visible surfaces, and grounding areas while leaving the remaining faces in the as-machined state. That avoids unnecessary masking, finish prep, and coating cost on surfaces that do not affect appearance or function.
Specifications
| Product Name | Cheap Zinc CNC Machined Parts Supplier |
|---|---|
| Manufacturer | XCM CNC |
| Factory Location | Shenzhen, Guangdong, China |
| Quality System | ISO 9001, ISO 13485, IATF 16949, GJB9001C |
| Machining Process | CNC machining |
| Material | Zinc |
| Material Grade | Zamak 3, Zamak 5, Zamak 8 by drawing review |
| Tolerance | +/-0.03 mm standard CNC machining tolerance |
| Precision Tolerance | +/-0.003 mm for selected critical features by drawing review |
| Surface Roughness | Ra 3.2 um milled, Ra 1.6 um precision, Ra 0.8 um turned or bored |
| Surface Treatment | Plating, powder coating, chromate finish, painting, or cosmetic prep by drawing review |
| Max Part Size | Milling 3000 x 1600 x 1400 mm / Turning diameter 1250 x 2000 mm |
| Inspection | CMM, roundness tester, height gauge, roughness tester, thread gauges |
| Application | Cost-sensitive die-cast trims, lock-hardware details, and screened shell interfaces |
| Typical Application | Cost-balanced zinc finish machining |
| Key Features | Die-cast follow-up machining, tolerance grading, allowance planning, and process consolidation |
| Critical QC Requirements | Casting datum review, fit-surface inspection, deformation control, finish allowance check, and post-process reinspection |
| Batch Range | 1 piece to planned repeat batches |
| MOQ | 1 piece |
| Typical Lead Time | Standard production 10-15 days by drawing review |
| Drawing Formats | STEP, IGS, DWG, PDF, X_T |
| Secondary Process | Deburring, tapping, cosmetic-prep machining, plating prep, and dimensional reinspection |
| Material Certificate | Material certificate by order requirements |
| Material Feature | Die-cast follow-up machining, fit-surface correction, and pre-finish machining review |
| Critical Tolerance Control | Flatness 0.02 mm, position tolerance 0.015 mm, and hole position 0.01 mm by drawing review |
Applications
Medium-Volume Die-Cast Dimension Correction
Typical Parts: Interior trim knob, door-latch trim cap, wire-harness clip
Automotive zinc die-cast parts often need CNC correction on fit holes and mounting faces, but the non-functional outer surfaces do not need the same tolerance level. Fit holes can be bored to H7 class and priced separately, mounting faces can be precision milled to Ra 1.6 um, and the remaining outer geometry can stay on the standard route to reduce unit cost.
Lock Hardware Fit Corrections
Typical Parts: Lock core housing, handle base, knob seat
Lock bores can be finished to Ra 0.8 um, visible faces before plating can be precision milled to Ra 1.6 um, and the non-contact faces can remain at Ra 3.2 um. Because plating thickness can shift fit size, the bore allowance is reviewed during DFM so rework after coating is less likely.
Shielding Covers and Connector Frames
Typical Parts: EMI shielding can, connector housing, non-load-bearing heat-sink bracket
Thin-wall shielding covers can complete grounding-face milling and clip-hole machining in one setup to reduce both positioning error and handling time. Grounding faces can stay at Ra 1.6 um for conductive contact, while non-functional side faces stay on the standard route and only the needed finish zones receive coating support.
Model Accessories and Decorative Small Parts
Typical Parts: Model decorative part, clip accessory, small housing
Decorative small parts often have a high ratio of visible surfaces, but not every face needs precision finishing. Visible faces can be held to Ra 1.6 um with the required tool-mark direction, while hidden faces stay on the standard route and multiple small parts can be grouped in one operation to reduce setup and tool-change time.
Why Choose Us
Qualified Systems and Equipment Coverage
XCM CNC runs zinc die-cast secondary machining under ISO 9001, ISO 13485, IATF 16949, and GJB9001C aligned quality systems, while using equipment from brands such as DMG, Mazak, Matsuura, and Brother for fit-surface correction and multi-face machining. For Zamak series projects, we review datum choice, pre-finish allowance, and reinspection priorities during drawing review.
Broad Size Range for Zinc Finish Machining
We support zinc finish machining from small connector-scale parts to larger housings, covers, and medium-size structural parts. Three-axis travel reaches 3000 x 1600 x 1400 mm and turning capacity reaches diameter 1250 x 2000 mm, while the final route still follows the die-cast datum, the pre-finish allowance, and the fixture method.
Tiered Equipment Strategy for Cost and Quality
XCM CNC uses CNC equipment from mainland China, Taiwan, Japan, and Europe or the US in a tiered production mix. Lower-tolerance operations can run on domestic or Taiwan machines, while higher-precision critical work moves to imported machines such as DMG and Mazak. That helps reduce cost without placing simple operations onto high-hour machines.
Quoted by Functional Tolerance and Roughness Level
Standard +/-0.03 mm tolerance and Ra 3.2 um milled faces stay inside the base quotation, while only drawing-defined precision features such as H7 bores, 0.015 mm position tolerance, or Ra 0.8 um bores are priced as premium work. That keeps the quotation tied to function instead of applying the highest standard to every face.
Process Consolidation and Inspection Scope Optimization
Zinc follow-up machining can combine milling, boring, tapping, and deburring into fewer setups to reduce both handling time and positioning error. Inspection scope also follows the drawing critical features, so fit bores and datums can receive full CMM attention while non-critical dimensions stay on a more efficient sampling route.
FAQ
What is included in the base machining cost for zinc die-cast finish parts?
The base quotation usually includes +/-0.03 mm standard dimensional tolerance, Ra 3.2 um milled finish, and common deburring or thread tapping. Precision features such as H7 bores, 0.015 mm position tolerance, or finer roughness targets are priced separately as premium machining work.
How does tolerance grading reduce zinc CNC machining cost?
By splitting the drawing into function-critical and standard features, only the bores, datums, and fit faces that truly need tight control use the slower feed, tighter inspection, and premium machine time. The remaining geometry can stay on the standard route, which lowers both machining and inspection cost.
Does choosing Zamak 3 vs Zamak 5 affect machining cost?
Machining cost is usually similar between Zamak 3 and Zamak 5 because their cutting behavior is close in follow-up machining. The bigger difference is often in the later finish route, where Zamak 5 can sometimes support plating appearance better and reduce finishing risk on certain visible parts.
How do you quote for zinc parts that need both machining and surface treatment?
The quotation usually splits machining and surface treatment into separate items. Machining follows tolerance grading and roughness zoning, while the finish route follows coating area, appearance level, and thickness requirement. Precision-hole allowance is reviewed during DFM so the coated part does not need rework later.
Which features usually add the most cost on zinc finish-machined parts?
Full-part tight tolerance, full-part precision milling, demanding finish routes, and oversized correction allowance usually add the most cost on zinc finish-machined parts. Splitting key functional faces from standard structure is often the simplest way to keep the total cost under control.
How do you reduce zinc machining cost without losing fit or appearance?
The normal approach is to optimize datum planning, correction allowance, tolerance grading, and the inspection scope instead of weakening the quality of the critical faces. Non-functional surfaces can use wider tolerance and roughness targets while fit and appearance zones keep the drawing standard.
Request a CNC Machining Quote from XCM CNC
Send us your drawings. Our team will review the file and reply with a machining quote. MOQ: 1 piece, with competitive low-cost pricing.
Email: [email protected] | WhatsApp: +8618638951317
