Custom Precision Zinc CNC Turned Parts

After CNC finish turning, zinc alloy die-cast sleeves, rings and cylindrical connector shells can achieve shaft diameter tolerances of h6 / +/-0.005 mm and roundness of 0.006 mm, suitable for rotational parts that primarily use inside and outside diameter fits. Bores, outside diameters, locating registers and end faces on die-cast blanks are finished on a Mazak i-100S turn-mill center or Jingshang 80 automatic lathe, with thin-wall clamping and post-plating dimensions considered together. XCM CNC is certified to ISO 9001, ISO 13485, IATF 16949 and GJB9001C. The MOQ is 1 piece, prototypes take 3-7 days and standard lead time is 10-15 days. Equipment listed for this machining service includes DMG 80mono, Mazak i-100S, Matsuura MX-520, Jingshang 80 automatic lathe, Brother / Taichung / Qiao Feng CNC 3016-4A machining centers, Shenyang CK61125X2000 lathe.

Zinc Shaft and Bore Fits with Roundness Control

After finish turning, zinc alloy sleeves and rings can achieve h6 / +/-0.005 mm shaft diameters and H7 / +/-0.006 mm bores, specified using ISO 286 fit grades. With a common rotational datum, inside-to-outside diameter coaxiality can reach 0.012 mm, roundness 0.006 mm and long-sleeve cylindricity 0.011 mm / 1030 mm. Roundness is checked on a roundness tester and coaxiality on a Hexagon Inspector Classic 06.08.06 CMM.

Thin-Wall Zinc Sleeve Turning and End-Face Runout

Minimum wall thickness for thin-wall zinc alloy sleeves is 0.5 mm, requiring blank pretreatment, stress-relief aging and optimized machining parameters. Direct three-jaw clamping can distort thin walls into a triangular form, so soft jaws that support the circumference or an expanding mandrel supporting the bore are used instead. Stock is removed in separate rough-turning and finish-turning stages. Face runout can be controlled to 0.012 mm, with a TRIMOS 600L height gauge supporting inspection.

Zinc Grooves, O-Ring Seats and Knurled Turned Knobs

Minimum groove width on zinc alloy turned parts is 0.5 mm. O-ring grooves have a minimum width of 1.0 mm and a depth tolerance of 0.01 mm. Knobs and handles can have straight or diamond knurling with modules of 0.3-1.0. Zinc has relatively low hardness, and excessive knurling pressure can raise burrs, so an additional edge-breaking operation of approximately 0.1 mm generally follows knurling.

Zinc Bore Honing and Plating Allowance for Turned Parts

Honed bores in zinc alloy rotational parts can achieve Ra 0.8 um for sliding fits and sealing bores. Plating thickness ranges from 3-20 um. H7 bores and h6 shaft diameters require dimensional allowance before plating to avoid post-plating nonconformance. Coating type and final plated dimensions depend on drawing and order requirements.

Quality Systems and Turning Equipment Resources

Projects operate under ISO 9001, ISO 13485, IATF 16949 and GJB9001C quality systems, with equipment from DMG, Mazak, Matsuura and Brother allocated according to part requirements.

Rotational Mating Surfaces Finished from Die-Cast Blanks

Turning support covers bores, outside diameters, registers and end faces on zinc alloy sleeves, cylindrical shells and knobs, together with threads, grooves, knurling and plating routes suitable for zinc substrates.

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

XCM CNC uses four tiers of turning and machining equipment from mainland China, Taiwan, Japan, and Europe and the United States. Less demanding operations such as knob outside diameters and general end faces use mainland Chinese or Taiwanese machines. h6 shaft diameters and bores requiring high roundness use imported machines such as DMG and Mazak. Equipment follows actual accuracy requirements, keeping simple turning off machines with higher hourly costs and reducing machining costs while meeting drawings.

Customization from Drawings or Physical Samples

Parts can be customized from 2D/3D drawings or customer-supplied used parts and samples, suitable for replacement orders for older lock sleeves and knobs. Critical dimensions are measured and established from the sample before quotation. Project information can be handled under an NDA.

Delivery from Prototypes to Batches

Single samples are generally delivered in 3-7 days. Batches are scheduled after you approve shaft diameters, bores and post-plating fits, with batch lead times of 10-15 days. This supports a regular schedule for single-part validation and small-to-medium batch replenishment.