Custom CNC Machining for Industrial Components
LANJIAN provides drawing-based CNC machining for castings, welded fabrications, housings, supports, and transmission components. We machine mounting faces, bearing bores, hole patterns, threads, and other functional features to the dimensional, geometric, and surface requirements confirmed for each project.
- Castings & Welded Fabrications
- Faces, Bores & Hole Patterns
- Drawing-Based Dimensional Control
- Multiple Delivery Conditions
Scope: Custom CNC-machined components for industrial equipment—not complete machines.
What Is CNC Machining?
CNC machining is a subtractive manufacturing process in which programmed machine tools remove material from a casting, welded fabrication, or other metal blank to create the dimensions, geometries, and surface conditions defined on an engineering drawing.
Depending on the component, CNC milling, turning, drilling, boring, reaming, and threading may be used to produce functional features that cannot be controlled by the blank-forming process alone. The required machining route depends on the part geometry, material, datum structure, machining access, tolerance, and inspection requirements.
What Does CNC Machining Add to an Industrial Component?
Mounting & Interface Surfaces
Creates controlled flat surfaces for mounting, alignment, sealing, or connection with other equipment components.
Bores & Hole Patterns
Produces bearing bores, locating holes, bolt patterns, and other features where diameter, position, or alignment is important.
Fits, Threads & Sealing Features
Machines shaft fits, internal and external threads, grooves, sealing faces, and other functional interfaces.
Controlled Geometric Relationships
Controls relationships such as flatness, parallelism, perpendicularity, position, and coaxiality where specified on the approved drawing.
Buyer Note: Not every surface needs to be machined. Critical features should be identified on the drawing, while suitable non-functional areas may remain as-cast or as-fabricated. Insufficient machining allowance, severe blank distortion, inaccessible features, or defects exposed during cutting may require further manufacturing review.
Verified CNC Machining Capability
LANJIAN provides drawing-based CNC machining for medium- and large-sized industrial components. Our machining scope covers castings, welded fabrications, housings, supports, shafts, flanges, and transmission components in different delivery conditions.
Capability | General Capacity | Typical Applications | |
CNC milling capacity | Up to 1,600 × 1,000 × 800 mm; workpiece weight up to 3,000 kg | Large castings, welded frames, housings, supports, and mounting structures | |
CNC turning capacity | Up to Ø600 × 2,000 mm | Shafts, sleeves, flanges, hubs, rollers, and rotational components | |
Machining operations | Milling, turning, facing, boring, drilling, reaming, tapping, threading, slotting, and multi-side machining | Mounting faces, bearing seats, hole patterns, threads, keyways, and assembly interfaces | |
Machinable materials | Cast iron, carbon steel, alloy steel, and stainless steel | Cast, welded, forged, and pre-machined workpieces | |
General dimensional tolerance | Typically ±0.10 mm | Non-critical machined dimensions and general assembly features | |
Controlled feature tolerance | Typically ±0.05 mm | ||
Critical local tolerance | Down to ±0.02 mm after engineering review | ||
Bore and fit capability | IT7–IT8 or H7 fits where specified and technically feasible | ||
Geometric accuracy | Flatness and parallelism typically 0.05–0.10 mm per 1,000 mm, subject to part review | ||
Surface roughness | Ra 3.2–6.3 μm for general machining; Ra 1.6–3.2 μm for finish machining | ||
Production volume | Single components, small batches, and repeat production |
Capability Summary
Our CNC machining capability is best suited to medium- and large-sized ferrous-metal components requiring controlled mounting faces, bearing bores, hole patterns, threads, sealing surfaces, and assembly interfaces. Parts can be supplied rough-machined, finish-machined, surface-finished, or ready for assembly.
Maximum size and minimum tolerance cannot normally be achieved simultaneously. Final capability depends on the component’s material, geometry, wall thickness, machining allowance, datum arrangement, workholding method, heat-treatment condition, and distortion risk. Critical requirements are confirmed through drawing review before quotation and production.
How Does Our CNC Machining Process Work?
LANJIAN converts castings, welded fabrications, and metal blanks into drawing-compliant industrial components through a controlled CNC machining process. The exact machining route depends on the workpiece condition, datum structure, tolerance requirements, and required delivery condition.
01 — Drawing & Requirement Review
We review the approved drawing, material, dimensions, tolerances, geometric controls, surface roughness, threads, fits, machining allowances, and inspection requirements. Conflicting or incomplete information is clarified before production.
02 — Workpiece & Machining Allowance Check
The casting, welded fabrication, or metal blank is checked for overall dimensions, deformation, machining accessibility, and available stock allowance. Conditions that could affect datum setup, wall thickness, or final dimensions are identified before machining.
03 — Process Planning & CAM Programming
Engineers determine the machining datums, setup sequence, workholding method, cutting tools, machining parameters, and inspection points. CAM toolpaths are programmed and checked for tool access, fixture clearance, overcutting, and possible collisions.
04 — Workholding & Datum Setup
The workpiece is located, supported, and securely clamped using appropriate fixtures, chucks, supports, or angle plates. Work coordinates, tool offsets, datum positions, and alignment are verified before cutting begins.
05 — Rough Machining
Most excess material is removed while controlled stock is retained for finishing. Rough machining creates stable reference surfaces and helps reveal the effects of uneven casting allowance, scale, residual stress, or weld distortion.
06 — Intermediate Inspection & Stabilization
Datums, remaining allowance, bore positions, wall thickness, and workpiece deformation are checked between critical setups. Large or stress-sensitive castings and welded components may require cooling, re-clamping, or stress-relief treatment before finish machining.
07 — Finish Machining & First-Part Verification
Mounting faces, bearing bores, hole patterns, threads, sealing surfaces, keyways, and other functional features are machined to their final requirements. Critical dimensions and geometric relationships are checked during machining. For repeat production, the first completed component is inspected before the remaining batch proceeds.
08 — Deburring, Final Inspection & Release
Burrs, sharp edges, chips, and machining residues are removed. Final dimensions, fits, threads, surface roughness, and specified geometric characteristics are inspected against the approved drawing before the component is released for surface treatment, assembly, packing, or shipment.
Process Control Note: Not every component requires the same number of setups or additional operations. Stress relief, CMM measurement, special gauges, surface treatment, and assembly are included only when required by the drawing or confirmed production plan.
How Is CNC Machining Quality Controlled?
CNC machining quality is controlled through approved production requirements, verified setups, appropriate cutting conditions, staged dimensional inspection, and documented final release. Controls are adjusted according to the component’s material, size, tolerance, geometry, production quantity, and functional features.
01 — Drawing & Quality Planning
Production follows the approved drawing revision. Materials, datums, critical dimensions, geometric tolerances, fits, threads, surface roughness, and inspection requirements are confirmed before machining.
02 — Workpiece & Allowance Verification
Castings, welded fabrications, and metal blanks are checked for identification, dimensions, deformation, usable datums, and machining allowance. Conditions that could affect workholding or final dimensions are reviewed before setup.
03 — Machine, Fixture & Gauge Readiness
Machine readiness, cutting tools, fixtures, supports, and workholding arrangements are checked before production. Measuring devices are selected according to the feature and tolerance, with their condition and calibration status confirmed.
04 — Setup, Datum & Program Verification
Workpiece alignment, datums, coordinates, tool offsets, clamping points, and fixture clearance are verified before cutting. Simulation, dry running, single-block execution, or trial cutting may be used according to machining risk.
05 — Cutting Parameter & Tool Control
Cutting speed, feed rate, depth of cut, coolant application, and chip evacuation are matched to the material and operation. Tool wear is monitored to reduce dimensional drift, poor surface roughness, and tool failure.
06 — First-Part & In-Process Inspection
For repeat production, the first completed part is inspected before the batch proceeds. Critical dimensions, remaining allowance, feature positions, and deformation are checked between rough and finish machining. Parts are allowed to stabilize before temperature-sensitive measurements.
07 — Final Dimensional & Surface Inspection
Completed parts are inspected for dimensions, fits, threads, geometric tolerances, and specified surface roughness. Appropriate calibrated instruments are selected, with CMM or special-gauge inspection used or coordinated when required.
08 — Nonconformance Control & Release
Nonconforming parts are identified, separated, and reviewed before rework, rejection, or customer-approved concession. Parts are released only after the required inspection results have been accepted.
Inspection Note: Not every dimension requires the same measuring method or inspection frequency. The inspection scope depends on feature function, tolerance, component size, production quantity, drawing requirements, and the agreed quality plan. Required inspection reports and document formats are confirmed before production.
Questions Buyers Ask About CNC Machining
Practical answers about drawings, materials, part size, tolerances, inspection, delivery conditions, cost, and lead time—before you submit a CNC machining RFQ.
Provide the 2D drawing, 3D model if available, material grade, quantity, delivery condition, and required date. Clearly identify critical tolerances, datums, fits, threads, surface roughness, coatings, and inspection documents. Samples or basic dimensions can support a preliminary review, but production requires an approved drawing.
We machine castings, welded fabrications, housings, supports, and metal blanks in cast iron, carbon steel, alloy steel, and stainless steel. Machinability is reviewed according to the material grade, hardness, heat-treatment condition, available stock allowance, and workpiece geometry.
Yes. We support individual components, small-batch requirements, and repeat OEM orders. The machining program, fixture strategy, first-part inspection, sampling level, and production arrangement are planned according to the quantity and repeatability requirements.
As a general reference, standard dimensions can typically be controlled to ±0.10 mm, selected functional features to ±0.05 mm, and critical local features down to ±0.02 mm after review. General machined surfaces are typically Ra 3.2–6.3 μm, with Ra 1.6–3.2 μm available for suitable finish-machined features.
Our general milling range covers workpieces up to approximately 1,600 × 1,000 × 800 mm and 3,000 kg, while turning capacity extends to approximately Ø600 × 2,000 mm. Final feasibility depends on the part envelope, centre of gravity, fixture space, tool access, lifting method, and tolerance requirements.
Critical features are controlled through datum planning, stable workholding, appropriate machining sequences, and staged inspection. Bore size, hole position, flatness, parallelism, perpendicularity, and runout are checked using measurement methods suited to the specified tolerance and feature size.
We control support positions, clamping force, stock removal, cutting parameters, and the sequence between rough and finish machining. Large, welded, thin-walled, or stress-sensitive components may require staged machining, cooling, re-clamping, or stress-relief treatment before final dimensions are completed.
Components can be supplied rough-machined, finish-machined, surface-finished, or ready for assembly. The required delivery condition is confirmed before quotation because it affects machining allowance, inspection scope, surface protection, packaging, cost, and lead time.
Inspection may cover dimensions, fits, threads, geometric tolerances, and specified surface roughness. Depending on the project, dimensional reports, CMM reports, material records, inspection photographs, special-gauge results, or third-party inspection can be provided or coordinated as agreed before production.
The main factors are material, workpiece size and weight, blank condition, material removal volume, number of setups, tolerance level, geometric requirements, surface roughness, inspection scope, quantity, and additional finishing. Price and lead time are confirmed after the drawing and production route have been reviewed.
Ready to Turn Your Drawing Into a Reliable CNC-Machined Component?
Send your drawing, 3D model, or available component requirements. LANJIAN will review the material, workpiece condition, machining feasibility, critical features, inspection scope, and delivery condition before quotation.
- Workpiece Size, Material and Machinability Reviewed
- Datums, Fits, Critical Tolerances and Surface Requirements Checked
- Workholding, Inspection and Finishing Requirements Coordinated
- Quotation Based on a Confirmed Machining Scope
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