Frequently asked questions

There is no fixed minimum order quantity. Prototypes and small batches are accepted, from a few dozen pieces upward. Annual production capacity is approximately 50,000 pieces, so both prototype quantities and repeat production volumes sit comfortably within it.

Email a 2D or 3D drawing to evelyn_lin@machiningservice.cn with the material, the tolerances that matter, the quantity and any surface finish requirement. Quotations are returned within 1–2 working days for complete drawings, and a design-for-manufacturing review is included at no cost. See what to include in a request.

3D models in STEP, IGES or Parasolid (X_T) format, and 2D drawings as PDF or DWG. A 3D model alone is usually enough for simple parts. For anything with critical fits, send both — the tolerance and datum scheme live on the 2D drawing, and without it the machining route has to be guessed.

Yes. Parts can be reverse-engineered from a physical sample where no drawing exists. A drawing-first route is preferred for anything with critical fits, because it allows tolerance stack-up to be reviewed before any material is cut.

No, a DFM review is included with every quotation at no cost. It looks at wall thickness, tool access, internal corner radii, the datum scheme and whether the specified tolerance can be held on the specified feature, and it flags any change worth making before production starts. See the DFM checklist.

Yes. Ask for an NDA before drawings are shared and one is put in place first. Drawings are not shared with third parties, and any subcontracted operation is placed under the same confidentiality requirement.

0.1 mm, 0.01 mm and 0.001 mm, depending on the feature and the process. Turning and milling on aluminium, brass and stainless steel routinely hold 0.01 mm. Bearing bores and sealing faces can be held to 0.001 mm with grinding, or 0.002 mm with wire EDM. Full table on the quality page.

Mark the dimensions the assembly depends on: fits, bore centres, sealing faces, mating surfaces and anything that must interchange with a part from another supplier. Those dimensions are then planned into the process route and reported explicitly on the inspection report, instead of being left under a general tolerance note.

0.5 mm is achievable on a well-supported feature, but thin walls deflect under cutting force and vibrate, which affects both tolerance and surface finish. As a practical guide, keep machined walls at 0.8 mm or above in aluminium and 1.0 mm or above in steel unless the feature is short and fully supported.

A machined internal corner cannot be sharper than the radius of the cutter that reaches it. Specifying a larger corner radius lets a larger, more rigid cutter be used, which cuts faster and holds tolerance better. As a rule, specify at least 1 mm, and in deep pockets at least one sixth of the pocket depth.

Yes, surface finish can be specified as an Ra value. Normal milling and turning produce around Ra 1.6 µm; fine finishing and grinding reach Ra 0.4 µm or better. State the Ra value on the drawing and it will be planned into the process route, since achieving it may add a finishing operation.

Aluminium (AL6061, AL6063, AL7075, AL2024, AL5052), stainless steel (SS303, SS304, SS316), brass (HPb59-1, CuZn39Pb1/2/3, CuZn40, C36000, C37710), bronze (C51000, C52100, C54400), carbon steel (Q235, 20#, 45#), titanium (Grade 2, Grade 5) and engineering plastics and composites including POM, PEEK, nylon, oiled nylon and carbon fibre. Full detail on the materials page.

AL6061 for most parts: good strength, excellent corrosion resistance, predictable machining and good anodising response. AL7075 is specified when strength is the binding constraint, AL5052 for sheet components that need forming, and AL6063 where a high-quality anodised cosmetic surface matters most.

SS316 contains molybdenum, which gives it resistance to chlorides and marine environments; SS304 does not. Choose SS316 for salt water, de-icing salts or chloride-bearing process chemistry. For indoor, freshwater or general industrial use, SS304 is sufficient and less expensive. Where welding is not required, SS303 machines far more easily than either.

Anodising, hard anodising, sand blasting, annealing, polishing, heat treatment, zinc plating, chrome plating, powder coating and painting. Finish certificates for outsourced processes are supplied with the shipment. See finishes by material.

100% of production parts are inspected before shipment, including full visual inspection against a documented standard inspection procedure. Batch sampling is not used as a substitute. Sampling applies only to incoming material checks, where the mill certificate already provides lot-level evidence.

Yes, both are supplied as standard with every shipment. The dimensional inspection report gives measured values against the dimensions specified on the drawing, and the material certificate gives the chemistry and mechanical values for the heat or lot used. First article inspection records are provided for new parts.

Parts that fail inspection are quarantined and never shipped. The deviation is measured and documented, the affected lot is traced back to its material lot, and you are told the measured values and the number of parts affected before any disposition decision is taken. Rework, replacement or acceptance as-is is agreed in writing, and the process cause is corrected and verified before the run resumes. See out-of-tolerance handling.

Buyers may nominate an inspection agency, and factory visits are accepted. Confirm the requirement at quotation so it can be scheduled into the inspection plan rather than added after the parts have been made.

The company operates a documented quality management system, and ISO 9001 and RoHS are recorded on its Made-in-China storefront. Certificate number and certification scope are supplied on request with a quotation. The website states a certification only where it can be evidenced, so the request route is given rather than a badge — see the verification record.

Sample parts are typically delivered in 3–7 working days. Parts requiring special material procurement or an outside finishing process take longer, and the quotation states the lead time for the specific part.

8–30 working days, depending on quantity, material and surface treatment requirements. Finishing processes such as anodising or plating are usually the longest element, so they are quoted as part of the schedule rather than added afterwards.

EXW, FOB, CIF, CNF, DDP and DDU. Parts ship by sea, air or express depending on size, weight and urgency.

T/T, PayPal and Western Union. Payment terms are confirmed with the order.

Poly bag and carton as standard. EPE foam or a wooden case is used for higher-value or fragile parts, and custom packing or labelling can be arranged at quotation.

For an order of 2,000 parts, the more cost-effective process depends on part geometry, material, tolerance requirements, and tooling costs.

CNC machining requires no dedicated casting mould, making it suitable for design changes, precision features, and low-to-medium production volumes.

Die casting requires an upfront tooling investment but can offer a lower unit cost for repeat production, especially when the part geometry is suitable for casting.

There is no fixed break-even quantity. For orders of 1,000–5,000 parts, Boyang Hardware can evaluate both processes based on the drawing, expected annual volume, and total production cost.

Investment casting is often suitable for complex shapes, curved surfaces, and internal features that would be difficult or expensive to produce entirely by CNC machining.

CNC machining offers greater flexibility for prototypes, design revisions, and parts requiring precise dimensions or machined surfaces.

The decision depends on geometry, material, required tolerances, tooling investment, and production quantity. Some components benefit from combining both processes: investment casting creates the near-net shape, followed by CNC machining of critical features.

Share your drawing and expected quantity to assess the suitable manufacturing route.

CNC machining is generally preferred when a part requires tight dimensional control, specific material properties, consistent surface finishes, or repeatable production.

CNC machining is often suitable for:

• Functional metal and plastic components
• Precision mating surfaces and threaded features
• Parts requiring consistent dimensions across batches
• Prototypes that must represent production material properties

3D printing is often suitable for:

• Early design and form-fit verification
• Complex internal geometries
• Rapid design iterations
• Low-volume parts that are difficult to machine

Both polymer and metal 3D printing are available manufacturing approaches. The suitable process depends on material, geometry, mechanical requirements, quantity, and total cost.

The main difference is how the cutting tool and workpiece move relative to each other, affecting machining accessibility, setup requirements, and geometric complexity.

• 3-axis CNC machining: Suitable for many flat surfaces, pockets, slots, and hole patterns. Multiple setups may be required to machine different sides.
• 4-axis CNC machining: Adds a rotary axis, allowing access to multiple faces and features around a workpiece with fewer setups.
• 5-axis CNC machining: Provides additional angular movement for complex contours, angled features, and difficult-to-reach surfaces.

More axes do not automatically guarantee tighter tolerances. Actual accuracy depends on machine condition, tooling, fixtures, material, part geometry, and inspection methods.

Boyang Hardware evaluates the machining approach according to the part drawing, required features, and production quantity.

Custom CNC machining prices are calculated from the part drawing and production requirements rather than a fixed price per piece.

The main cost factors include:

• Material: Type, grade, size, and material utilization
• Machining time: Cutting operations and cycle time
• Setups: Number of fixtures and workpiece repositioning operations
• Tolerances: Required accuracy and additional finishing operations
• Surface treatment: Anodizing, plating, polishing, or other specified finishes
• Order quantity: Setup and programming costs distributed across the batch
• Inspection: Measurement requirements and documentation

A simple part with standard tolerances may cost significantly less than a similar-sized component requiring multiple setups and precision finishing.

Send your 2D or 3D drawing, material requirements, and quantity to Boyang Hardware for a quotation, normally provided within 1–2 working days.

CNC machining costs increase when a design requires additional machine time, complex setups, specialized tooling, or demanding inspection.

Common cost drivers include:

• Tolerances tighter than the part's functional requirements
• Deep pockets, narrow slots, and difficult-to-access features
• Multiple setups or complex fixturing
• Hard-to-machine materials
• Extensive surface finishing requirements
• Small batches with higher setup costs per part

Cost reductions may be possible by simplifying non-critical features, applying tight tolerances only where needed, selecting suitable materials, and combining production quantities.

Boyang Hardware can review drawings for potential manufacturing and cost considerations before quotation.

Smaller production batches generally have a higher unit cost because programming, setup, and inspection preparation costs are distributed across fewer parts.

Larger batches may reduce the unit price, although the actual savings depend on material purchasing, machining cycle time, and production requirements.

For recurring orders, sharing your estimated annual demand and preferred shipment quantities can help evaluate different production and pricing options.

Boyang Hardware can quote different quantity levels so buyers can compare unit costs before placing an order.

Shipping terms affect which transportation, customs, insurance, and delivery costs are included in the supplier's quotation and which remain the buyer's responsibility.

Common international trade terms include:

• EXW: The buyer takes responsibility for transportation and most related costs from the agreed pickup point.
• FOB: The seller delivers goods on board the vessel at the named port of shipment. The buyer generally handles main freight and import costs.
• CIF: The seller pays ocean freight and the required minimum insurance to the named destination port, while risk transfers when goods are loaded on board at origin.
• CFR (also called CNF): Similar to CIF, but without the seller's obligation to arrange cargo insurance.
• DDP: The seller assumes responsibility for delivery to the agreed destination, including applicable import clearance and duties.
• DAP: The seller arranges delivery to the named destination, while the buyer generally handles import clearance and duties.

The applicable shipping term, destination, and included charges should be confirmed in the quotation.

For an accurate landed-cost comparison, buyers should consider freight, insurance, customs duties, taxes, clearance fees, and local delivery charges.

Tighter tolerances can increase CNC machining costs when they require slower cutting speeds, specialized tooling, additional setups, temperature control, or more extensive inspection.

For example, a feature requiring ±0.01 mm may need different machining and measurement arrangements than one allowing ±0.05 mm. Extremely tight tolerances, such as ±0.001 mm, may require specialized finishing and inspection processes, depending on the part.

The cost impact depends on material, feature size, geometry, and the manufacturing method.

To control costs, specify tight tolerances on critical functional dimensions and use appropriate general tolerances for non-critical features.

Boyang Hardware can assess tolerance requirements from the drawing and identify potential manufacturing considerations before production.

Production lead times depend on part complexity, material availability, order quantity, surface treatment, and inspection requirements.

Boyang Hardware's published lead-time references are:

• Samples: Normally 3–7 working days
• Mass production: Normally 8–30 working days

These are general estimates rather than guaranteed delivery dates. The actual schedule is confirmed according to the order requirements and production arrangements.

Buyers can share their required delivery date during quotation so the production schedule can be evaluated before order confirmation.

Drawing revisions made after production begins may affect machining programs, tooling, fixtures, material usage, cost, and delivery schedules.

When a revised drawing is received, the affected features and production stage should be reviewed before the change is implemented.

The review may include:

• Differences between the original and revised drawings
• Quantity already produced or in progress
• Required machining or tooling changes
• Possible rework or replacement requirements
• Additional costs and schedule adjustments

The revised requirements and their impact should be confirmed in writing before proceeding with the affected production work.

To reduce revision-related risks, buyers should provide clearly identified drawing versions and highlight any critical changes.

Shipping damage can occur if parts are exposed to impact, vibration, moisture, or unsuitable handling during transportation.

Boyang Hardware's published packaging options include poly bags and cartons, with EPE foam or wooden cases available for parts requiring additional protection.

Packaging requirements should be discussed during quotation, particularly for precision surfaces, fragile features, and higher-value components.

If damage is discovered after delivery, buyers should retain the packaging and provide:

• Photographs of the damaged parts and packaging
• Part numbers and affected quantities
• Packing list or shipment reference
• A description of the damage

Responsibility for transportation damage and the applicable claim process depend on the agreed shipping terms, carrier arrangements, and order conditions.

Contact Boyang Hardware with the shipment details so the issue can be reviewed and the next steps discussed.