Custom Brass CNC Turning and Milling Parts

XCM CNC produces brass turned-milled parts with turned sealing and mating diameters, milled side holes and wrench flats related to a common rotational datum. Typical parts include connector bodies, valve fittings and sensor mounts. Turning operations use Mazak, DMG and other machines, with +/-0.003 mm achievable on critical mating features. The factory is certified to ISO 9001, ISO 13485, IATF 16949 and GJB9001C. The MOQ is 1 piece, with samples in 3-7 days and batch orders in 10-15 days. For a quote, provide drawings, the grade and quantity, and identify hole-location datums and inspection items. Equipment listed for this machining service includes DMG 80mono, Mazak I-100S, Matsuura MX-520, Jingshang 80 automatic lathe, Brother / Taichung / Qiao Feng machining centers, Shenyang CK61125X2000 lathe.

Brass CNC Turning Tolerance on Sealing and Mating Diameters

Brass turned sealing diameters can be held to +/-0.003 mm on parts under 100 mm, with h6 / +/-0.005 mm available for shaft fits. Roundness reaches 0.006 mm and coaxiality between stepped diameters reaches 0.012 mm when the sealing seat and thread are turned in one clamping. Free-cutting brass such as C36000 produces short chips, which helps keep the turned OD at Ra 0.8 um without built-up edge marks.

Brass Turn-Mill Side Port Position and Re-Clamping Control

Side ports and cross-holes on brass turn-mill fittings are positioned to 0.01 mm relative to the turned axis. Multi-face machining in a single clamping covers parts up to 600 x 1200 x 500 mm, which avoids the datum shift that re-clamping introduces. Axial holes are drilled up to L/D = 10. Cross-hole intersections in brass leave thin, soft burrs, so the deburring step runs after the final milling pass rather than between operations.

Brass Turned and Milled Surface Finish Grades

Surface finish on brass turn-mill parts is specified by feature: Ra 0.8 um on turned OD, Ra 1.6 um on fine-milled wrench flats and Ra 3.2 um on non-functional milled faces. Sealing faces can be lapped to Ra 0.4 um. Precision polishing on critical areas reaches Ra 0.015 um and is quoted only for selected features after drawing review. Specifying finish grades per feature avoids paying polishing hours on surfaces that do not seal or mate.

Brass Fitting Inspection with Hexagon CMM and 2.5D Vision

Brass turn-mill parts are inspected on a Hexagon Inspector Classic 06.08.06 CMM for side-hole position (0.01 mm) and coaxiality (0.012 mm) against the shared rotational datum. Wrench-flat widths and planar hole patterns are measured on the WanHao Rational VMS-3020G 2.5D video measuring machine. Step heights are checked with the TRIMOS 600L height gauge. GD&T callouts follow ISO 1101, and pipe threads are checked with NPT or BSP go/no-go gauges.

Quality Systems and Mixed-Feature Inspection

We operate under ISO 9001, ISO 13485, IATF 16949 and GJB9001C quality systems, with machining equipment from DMG, Mazak, Matsuura and Brother and measuring equipment from Hexagon and Leader. Turned mating surfaces, side holes and milled flats can be verified within the inspection scope agreed for the order.

Drawing-Based Turning, Milling and Secondary Operations

From small connectors to large structural parts, we plan turning, milling and required secondary operations against the drawing. For rotational mating surfaces and side features on brass fittings, defining their datum relationship first helps buyers establish the complete machining scope.

Tiered Equipment Strategy for Low-Cost CNC Machining, Quality-Assured Production

XCM CNC uses four tiers of CNC equipment from mainland China, Taiwan, Japan, and Europe and the United States. Operations with less demanding tolerances run on mainland Chinese or Taiwanese machines, while high-precision operations use imported machines such as DMG and Mazak. Equipment is allocated according to the accuracy the part requires, avoiding machines with higher hourly costs for simple operations and reducing machining costs while meeting drawing requirements.

Drawing Review and Datum Feedback before Quotation

After receiving drawings, engineers check for unclear relationships between turned and milled features, such as a side hole without a specified outside-diameter datum or conflicting tolerances between wrench flats and sealing faces. These issues are reported with the quote to avoid discovering differing interpretations only after samples have been made.

First-Article Approval before Batch Production, with NDA Support

Samples are delivered in 3-7 days with a dimensional inspection report. Batch production begins after customer sample approval. Standard lead time is 10-15 days, depending on complexity and quantity. For unpublished designs, an NDA can be signed before drawings are sent.