Our CNC Flame Cutting Services
Need CNC Flame Cutting that delivers high-speed, cost-effective, and precise metal cutting for large-scale projects? Our services leverage advanced thermal cutting technology, decades of expertise, and state-of-the-art CNC systems to handle thick steel plates, custom metal components, and high-volume fabrication—ideal for construction, shipbuilding, and heavy machinery. Whether you need large structural parts or intricate custom cuts, we combine high efficiency and consistent quality to meet your deadlines and specifications.
What Is CNC Flame Cutting?
CNC Flame Cutting (also known as CNC Oxygen Fuel Cutting) is a thermal cutting process that uses a controlled flame and a jet of pure oxygen to cut through ferrous metals (metals containing iron). Unlike manual flame cutting, which relies on human guidance, CNC (Computer Numerical Control) flame cutting uses pre-programmed software to control the tool path, cutting speed, and oxygen flow—ensuring precise, repeatable cuts on large or thick workpieces.
The core concept of CNC Flame Cutting lies in its reliance on oxidation: the flame (typically fueled by acetylene, propane, or natural gas) preheats the metal to its ignition temperature (around 870°C for steel), then a high-pressure oxygen jet is directed at the heated area. This oxygen reacts with the iron in the metal, creating intense heat (up to 3,150°C) that melts and blows away the molten metal—forming a clean cut. It is the most widely used flame cutting process for thick steel (10mm–300mm) due to its cost-effectiveness and versatility.
| Key Term | Meaning | Role in CNC Flame Cutting |
| CNC Flame Cutting | Computer-controlled oxygen-fuel thermal cutting process | Automates cutting parameters for precision and consistency across large/thick workpieces |
| Flame Cutting Process | Thermal cutting method using preheating flame + oxygen jet | Core operation that melts and removes metal to form desired shapes |
| Thermal Cutting | General category of cutting processes using heat (not mechanical force) | Encompasses CNC Flame Cutting, plasma cutting, and laser cutting—CNC Flame Cutting is optimal for thick ferrous metals |
| Oxygen Fuel Cutting | Synonym for CNC Flame Cutting; uses oxygen + fuel gas for cutting | Provides the high heat needed to cut through thick steel (10mm+) |
Our Capabilities: What We Offer in CNC Flame Cutting
With 25+ years of experience and deep technical expertise in thermal cutting, our team handles everything from small custom parts to massive structural steel plates. We don’t just offer standard cutting—we tailor our services to match your project’s unique needs, whether you’re fabricating ship hulls or heavy machinery components.
Our Core CNC Flame Cutting Capabilities
| Capability | Details | Typical Applications |
| Custom Flame Cutting | Design and execute non-standard cuts (e.g., irregular shapes, beveled edges, notches) for unique components; works with 2D/3D CAD designs | Custom machinery frames, shipbuilding structural parts, construction brackets |
| Precision Flame Cutting | Achieve dimensional tolerance of ±0.5mm/m (±0.02” per foot) and cutting accuracy of ±0.3mm for parts up to 10m long; ideal for tight-fitting assemblies | Aerospace ground support equipment, heavy machinery joints, precision fabrication parts |
| Range of Services | Straight cutting, bevel cutting (0°–45°), hole cutting (minimum diameter: 15mm), slot cutting, and contour cutting; handles single parts or batch production | Construction steel beams, ship hull plates, industrial furnace components |
| Large-Scale Cutting | Process workpieces up to 12m (40ft) in length, 3m (10ft) in width, and 300mm (12in) in thickness; supports multi-plate stacking (up to 5 plates, total thickness 150mm) | Bridge structural parts, offshore platform components, large pressure vessel shells |
| High-Volume Production | Cut up to 500 parts per shift with automated loading/unloading systems; optimized for repetitive cuts (e.g., standard steel brackets) | Mass-produced construction connectors, heavy machinery base plates, automotive chassis components |
Our fleet includes 8 CNC flame cutting machines (with gantry-style frames for large workpieces) and specialty tools for bevel cutting and precision holes. We’ve delivered projects for clients in 12+ industries, proving our ability to scale from prototypes to large-scale fabrication.
Process: How CNC Flame Cutting Works
The CNC Flame Cutting process (also called Oxygen Fuel Cutting) is a structured, step-by-step workflow designed to ensure safety, precision, and efficiency—critical for working with high heat and thick metals.
Step-by-Step CNC Flame Cutting Operation Procedure
- Machine Setup: The metal workpiece (typically steel plate) is cleaned (to remove rust, paint, or oil—contaminants can affect cut quality) and secured to the machine’s cutting table using clamps or magnetic chucks. Our technicians load the CNC program (created from your CAD design) into the machine’s control system, which defines the tool path, cutting speed, preheat temperature, and oxygen pressure.
- Tool Preparation: The cutting torch (equipped with separate nozzles for preheating and oxygen jet) is calibrated. We select the nozzle size based on material thickness: larger nozzles for thick steel (100mm+) to deliver more heat and oxygen, smaller nozzles for thin steel (10mm–50mm) for precise cuts.
- Cutting Sequence:
- Preheating: The torch moves to the starting point and uses the fuel gas (e.g., acetylene) + air mixture to preheat the metal to its ignition temperature (870°C for steel)—visible as a bright red glow.
- Ignition & Cutting: Once preheated, the high-pressure oxygen valve opens, directing a jet at the heated area. The oxygen reacts with iron to create molten oxide, which is blown away by the oxygen flow—starting the cut.
- Following Tool Path: The CNC system moves the torch along the pre-programmed tool path at a constant speed (50–500 mm/min, depending on material thickness: slower for thick steel, faster for thin steel). For bevel cuts, the torch tilts to the desired angle (0°–45°) using a rotary axis.
- Quality Check: After cutting, the workpiece is cooled (naturally or with water spray) and inspected. We use tape measures, calipers, and laser measuring tools to verify dimensional tolerance and cutting accuracy; we also check for dross (molten metal residue) on the cut edge.
- Post-Cutting Processing: Dross is removed via grinding or deburring (part of our standard service), and the workpiece is prepared for surface treatment (e.g., painting or heat treatment) if needed. The machine resets for the next workpiece—automated systems reduce downtime for high-volume runs.
Cycle time depends on material thickness and cut length: a 1m-long cut on 50mm steel takes ~2 minutes, while a 5m-long cut on 200mm steel takes ~15 minutes.
Materials: What Can We Cut with CNC Flame Cutting?
CNC Flame Cutting is optimized for flame cutting materials that contain iron (ferrous metals), as the process relies on iron oxidation to generate heat. It works poorly on non-ferrous metals (e.g., pure aluminum, copper) because they do not oxidize at the required temperature—for these, we recommend plasma or laser cutting.
Common Materials for CNC Flame Cutting
| Material Type | Examples | Key Properties | Ideal Applications |
| Steel | Mild steel (A36), carbon steel (S45C), alloy steel (4140) | High iron content (95%+), easy to oxidize, cost-effective; thickness range: 10mm–300mm | Construction beams, ship hull plates, machinery frames, pressure vessels |
| Stainless Steel | Austenitic stainless steel (304, 316) | Contains iron (60%–70%) but also chromium (18%+), which forms a protective oxide layer; requires higher preheat temperature | Industrial furnace parts, chemical processing equipment, food-grade machinery |
| Iron | Cast iron (gray iron, ductile iron) | High iron content (90%+), brittle but durable; thickness range: 20mm–250mm | Engine blocks, pipe fittings, heavy machinery bases |
| Other Ferrous Metals | High-strength low-alloy (HSLA) steel, weathering steel (Corten A) | HSLA: High strength, low weight; weathering steel: Corrosion-resistant | Bridge components (HSLA), outdoor structures (weathering steel) |
Note: Non-ferrous metals (aluminum, copper, brass) are not suitable for CNC Flame Cutting—their oxide layers melt at higher temperatures than the base metal, preventing clean cuts. For these materials, we offer complementary plasma cutting services. We optimize cutting parameters for each material: for mild steel (A36), we use acetylene fuel (high heat) and 50 psi oxygen pressure; for stainless steel (304), we use propane fuel (slower preheat) and 60 psi oxygen pressure to penetrate the chromium oxide layer.
Surface Treatment: Enhancing Cut Quality & Durability
After CNC Flame Cutting, surface treatment (or finishing) is critical to improve the workpiece’s appearance, durability, and functionality—especially for parts exposed to harsh environments (e.g., construction, shipbuilding) or requiring tight fits (e.g., machinery).
Our Surface Treatment Options for CNC Flame Cut Parts
| Treatment Type | Process | Benefits | Typical Use Cases |
| Grinding | Using abrasive wheels to remove dross (molten metal residue) and smooth cut edges; achieves surface roughness of Ra 3.2–6.3 μm | Eliminates sharp edges, improves fit for assembly, removes corrosion-prone dross | Machinery joints, structural steel connections, precision fabrication parts |
| Deburring | Manual or automated removal of small burrs (metal projections) from cut edges; uses wire brushes or deburring tools | Prevents injury during handling, improves aesthetic quality, ensures proper part alignment | Automotive chassis components, handrails, consumer-facing metal parts |
| Painting | Applying industrial paint (epoxy, enamel) via spray or brush; provides UV and corrosion resistance | Outdoor construction parts (beams, brackets), ship hull components, machinery exteriors | |
| Coating | Applying protective layers (zinc coating, powder coating); zinc coating prevents rust, powder coating adds durability | Construction connectors (zinc coating), industrial equipment (powder coating) | |
| Heat Treatment | Annealing (softening) or quenching (hardening) the cut part to adjust mechanical properties; reduces internal stress from cutting heat | Heavy machinery shafts (hardening), structural parts (annealing to prevent cracking) | |
All our surface treatments meet industry standards: our zinc-coated parts pass ASTM B633 salt spray tests (800+ hours of corrosion resistance), and our ground edges meet ISO 8787 standards for smoothness—critical for tight-fitting machinery components.
Tolerances: The Precision We Deliver
While CNC Flame Cutting is not as precise as laser cutting (due to thermal expansion of metal), our process is optimized to achieve tight tolerances and high cutting accuracy—critical for structural parts and assemblies that require a perfect fit.
Our Tolerance Capabilities vs. Industry Averages
| Metric | Our Capability | Industry Average | Advantage |
| Dimensional Tolerance | ±0.5mm/m (±0.02” per foot) | ±1.0mm/m (±0.04” per foot) | 2x tighter tolerance for large workpieces (e.g., 10m steel beams have ±5mm vs. ±10mm industry average) |
| Cutting Accuracy | ±0.3mm for parts ≤5m; ±0.5mm for parts 5m–12m | ±0.5mm for parts ≤5m; ±1.0mm for parts 5m–12m | More precise cuts for both small and large components |
| Surface Roughness (Cut Edge) | Ra 3.2–6.3 μm (after grinding); Ra 12.5–25 μm (as-cut) | Ra 6.3–12.5 μm (after grinding); Ra 25–50 μm (as-cut) | Smoother edges that require less post-finishing, saving time and cost |
| Bevel Angle Tolerance | ±1° (for 0°–45° bevels) | ±2° (for 0°–45° bevels) | More accurate bevel angles for welded joints (critical for structural strength) |
To maintain these tolerances, we use CNC flame cutting machines with linear encoders (accuracy: ±0.05mm/m) and thermal compensation software—this adjusts the tool path to account for metal expansion during cutting. We also calibrate machines daily and use high-precision nozzles (±0.1mm orifice tolerance) to ensure consistent oxygen flow.
Advantages: Why Choose CNC Flame Cutting Over Other Methods?
CNC Flame Cutting offers unique benefits that make it superior to other thermal cutting methods (e.g., plasma, laser) for thick ferrous metals. Its combination of cost-effectiveness, high efficiency, and versatility makes it the top choice for large-scale metal fabrication.
Key Advantages of CNC Flame Cutting
| Advantage | Description | Impact on Your Project |
| Cost-Effective for Thick Metals | Low operating cost (fuel gas + oxygen is cheaper than plasma or laser energy); ideal for steel ≥10mm thick | Saves 30–50% on cutting costs vs. laser cutting for 100mm steel plates |
| High-Speed Cutting for Large Parts | Cuts thick steel (50mm–300mm) faster than plasma cutting (e.g., 5m cut on 200mm steel takes 15 mins vs. 25 mins for plasma) | Reduces production time for large projects (e.g., ship hull fabrication) by 20–30% |
| Versatility for Large Workpieces | Handles parts up to 12m × 3m × 300mm—larger than most plasma/laser machines (max 6m × 2m) | Eliminates the need to split large parts (e.g., bridge beams) into smaller sections, saving assembly time |
| Consistency Across Batches | CNC programming ensures every part has identical cuts—critical for repetitive components (e.g., construction brackets) | Lowers scrap rate to <2% (vs. 5–8% for manual flame cutting) |
| Easy Bevel Cutting | Integrates rotary axes to cut bevels (0°–45°) in one pass—no need for secondary operations (e.g., grinding) | Saves 1–2 hours per part on beveling, reducing lead times for welded components |
For example, a shipyard switched from manual flame cutting to our CNC Flame Cutting service for hull plates (20mm–50mm thick). Their cutting time per plate dropped from 4 hours to 1.5 hours, and scrap rate fell from 7% to 1.5%—saving $120,000 monthly in labor and material costs.
Applications Industry: Where CNC Flame Cutting Is Used
CNC Flame Cutting’s ability to handle thick ferrous metals and large workpieces makes it indispensable across industries that rely on heavy metal fabrication. It is the go-to method for structural parts, machinery components, and large-scale assemblies.
Industry Applications of CNC Flame Cutting
| Industry | Common Cut Parts | Why CNC Flame Cutting Is Ideal |
| Construction | Steel beams, columns, brackets, bridge structural parts, building frames | Handles large workpieces (up to 12m) and thick steel (10mm–300mm); cost-effective for high-volume projects |
| Shipbuilding | Hull plates, deck components, bulkheads, propeller shafts (housings) | Cuts thick steel (20mm–200mm) required for ship structural integrity; supports bevel cutting for welded joints |
| Heavy Machinery | Machinery frames, base plates, hydraulic cylinder barrels, excavator arm components | Provides precise cuts for tight-fitting assemblies; cost-effective for large, heavy parts |
| Fabrication | Custom metal enclosures, industrial ovens, pressure vessels, storage tanks | Accommodates custom cuts (irregular shapes, notches) and large diameters (up to 1m holes for tanks) |
| Automotive | Chassis components, truck frames, engine mounts (for heavy-duty vehicles) | Handles thick steel (10mm–50mm) for vehicle structural strength; supports high-volume production |
| Aerospace | Ground support equipment (e.g., aircraft jacks, engine stands), large tooling fixtures | Meets precision requirements for equipment that holds aircraft; cuts thick steel for load-bearing parts |
| Metalworking | Raw material sizing (cutting large steel plates into smaller blanks), custom prototypes | Cost-effective for sizing raw materials; flexible for one-off custom parts |
In the construction industry, our CNC Flame Cutting services have helped a leading construction firm cut 1,500 steel beams (12m long, 50mm thick) for a highway bridge—delivering all parts 2 weeks ahead of schedule and within budget, thanks to our high-speed cutting and automated systems.
Manufacturing Techniques: The Technology Behind Our CNC Flame Cutting
Our CNC Flame Cutting services rely on advanced manufacturing techniques and cutting-edge technology to maximize precision, efficiency, and safety—critical for handling thick metals and large workpieces. We combine proven thermal cutting practices with innovative tools to optimize every step of the process.
Core Manufacturing Techniques for CNC Flame Cutting
| Technique | How It Works | Benefit |
| Thermal Compensation Software | Our CNC systems use built-in software that calculates metal expansion (based on material type, thickness, and preheat temperature) and adjusts the tool path in real time. For example, it expands the programmed cut by 0.2mm/m for 100mm thick steel to account for shrinkage as the metal cools. | Eliminates dimensional errors from thermal expansion/shrinkage; improves cutting accuracy by 30% |
| Dual-Torch Cutting | We use machines with two synchronized cutting torches that work in parallel—ideal for high-volume production of identical parts (e.g., construction brackets). The torches follow mirrored tool paths, cutting two parts at once. | Doubles production output; reduces labor costs by 50% for batch runs |
| Automated Loading/Unloading Systems | Robotic arms or gantry cranes load raw steel plates (up to 300kg) onto the cutting table and unload finished parts—24/7 operation with minimal human intervention. The system integrates with our CAD software to prioritize parts based on urgency. | Increases production capacity by 40%; reduces downtime between cuts (from 15 mins to 2 mins) |
| High-Precision Nozzle Technology | We use diamond-orifice nozzles (instead of standard brass) that maintain consistent oxygen flow (±1% variation) even after 500+ cuts. The nozzles are designed with optimized preheat flame patterns to reduce preheating time by 20%. | Extends nozzle life (from 100 cuts to 500 cuts); reduces preheating time for thick steel (100mm+ takes 2 mins vs. 2.5 mins) |
| Integrated Dust & Fume Extraction | Our cutting tables are equipped with under-table suction systems that capture 95% of cutting fumes and dust. The system filters harmful gases (e.g., iron oxide fumes) to meet OSHA air quality standards. | Improves workplace safety; eliminates the need for post-cutting cleaning of the cutting table |
| CNC Machining Integration | Our flame cutting machines are linked to CAD/CAM software (AutoCAD, SolidWorks) that imports 2D/3D designs and generates optimized tool paths automatically. The software also simulates the cut to identify potential issues (e.g., collision between torch and workpiece) before production. | Reduces programming time by 60%; minimizes errors from manual programming |
We also invest in innovation—our latest machines feature AI-powered cutting parameter optimization: the system learns from past projects (e.g., how 200mm mild steel reacts to different oxygen pressures) and adjusts settings to improve cut quality and speed for future jobs.
Case Studies: Success Stories From Our Clients
Our CNC Flame Cutting services have helped clients across industries solve complex fabrication challenges, reduce costs, and meet tight deadlines. Below are two detailed real-world examples of our work.
Case Study 1: Large-Scale Bridge Construction for a State DOT
Client: A state Department of Transportation (DOT) building a 2km highway bridge requiring 2,500 structural steel beams (12m long, 80mm thick mild steel A36).
Challenge: The client’s previous supplier used manual flame cutting, which took 4 hours per beam and had a 7% scrap rate (due to uneven cuts and dimensional errors). They needed all beams delivered in 8 weeks to avoid project delays, but manual cutting would take 12 weeks—putting the entire bridge timeline at risk. Additionally, the beams required 45° bevel cuts for welded joints, which the supplier could only do via secondary grinding (adding 1 hour per beam).
Solution: We deployed 4 dual-torch CNC flame cutting machines with automated loading/unloading systems. We optimized the tool path to cut two beams at once (via dual torches) and integrated bevel cutting into the main process (no secondary grinding needed). Our thermal compensation software adjusted for steel expansion, ensuring each beam met the ±0.5mm/m dimensional tolerance. We also prioritized beam production based on the construction schedule (delivering critical support beams first).
Results:
- Production Time: Cut each beam in 1 hour (vs. 4 hours manual), completing all 2,500 beams in 6 weeks—2 weeks ahead of schedule.
- Scrap Rate: Dropped to 1.2% (from 7%), saving 155 beams (≈$77,500 in material costs).
- Labor Savings: Eliminated 20 secondary grinding positions, reducing labor costs by $120,000.
Client Feedback: “The CNC Flame Cutting service delivered the beams ahead of schedule and with perfect dimensional accuracy—critical for our bridge’s structural integrity. The integrated bevel cutting saved us weeks of extra work, and the cost savings helped us stay within budget.”
Case Study 2: Custom Ship Hull Plates for a Shipyard
Client: A shipyard building 5 cargo ships, each requiring 300 custom-shaped hull plates (20mm–50mm thick mild steel; irregular shapes with multiple notches and 30° bevels).
Challenge: The shipyard’s manual cutting process required 2 hours per plate and struggled to replicate the custom shapes consistently—leading to misfits during hull assembly (15% of plates had to be re-cut). They needed to reduce assembly time (each ship took 12 weeks to build) and ensure all plates fit seamlessly to avoid water leakage risks.
Solution: We used 5-axis CNC flame cutting machines (with rotary axes for bevel cuts) and imported the shipyard’s 3D hull CAD models directly into our CAM software. The software generated precise tool paths for each custom plate, and our high-precision nozzles ensured consistent cut quality. We also added in-process laser inspections (after each cut) to verify shape accuracy before unloading. For high-volume plates (e.g., standard notched sections), we used multi-plate stacking (3 plates at once) to speed up production.
Results:
- Production Time: Cut each plate in 30 minutes (vs. 2 hours manual), reducing hull plate production from 6 weeks per ship to 2 weeks per ship.
- Fit Accuracy: 99.5% of plates fit perfectly during assembly (vs. 85% manual), eliminating re-cuts and reducing ship building time by 4 weeks per vessel.
- Cost Savings: Saved the shipyard 250,000pershipinreworkandlaborcosts—totalsavingsof1.25 million across 5 ships.
Client Feedback: “The CNC Flame Cutting service’s ability to replicate custom hull shapes with such precision was game-changing. Our assembly teams now spend less time adjusting plates and more time building ships—we’ve increased our annual ship output from 3 to 5 vessels.”
Why Choose Us: Your Trusted CNC Flame Cutting Partner
With dozens of CNC Flame Cutting providers in the market, what sets us apart? We combine technical excellence, customer-centric service, and a track record of delivering results—making us the go-to partner for large-scale, high-precision metal fabrication.
Top 5 Reasons to Choose Our CNC Flame Cutting Services
- Unmatched Expertise & Experience: Our team has 25+ years of specialized experience in thermal cutting, with deep knowledge of flame cutting techniques for thick ferrous metals (10mm–300mm). Our engineers are certified in AWS (American Welding Society) standards and have worked on iconic projects (highway bridges, cargo ships, industrial furnaces). We don’t just cut metal—we provide design feedback to optimize parts for CNC Flame Cutting (e.g., suggesting notch sizes that reduce cut time).
- Cutting-Edge Technology & Innovation: We invest in the latest CNC flame cutting machines (80% of our fleet is less than 5 years old) and proprietary manufacturing techniques (e.g., thermal compensation software, AI parameter optimization). This technology ensures we deliver the tightest tolerances and fastest lead times in the industry—even for large workpieces.
- Flexible & Customizable Solutions: We handle projects of all sizes—from 1 custom prototype to 10,000 high-volume parts. Our custom flame cutting capabilities let us tackle irregular shapes, beveled edges, and complex contours that other providers can’t. We also offer complementary services (grinding, painting, heat treatment) to deliver “turnkey” parts—no need to coordinate with multiple vendors.
- Strict Quality Control & Reliability: We follow a 7-step quality assurance process—from raw material inspection (only certified steel from ISO 9001 suppliers) to in-process laser checks and final dimensional verification. Our reliability rate is 99.5%—we meet 99.5% of delivery deadlines, even for rush orders. We back every project with a “Fit Guarantee”: if a part doesn’t fit your assembly, we re-cut it for free.
Customer-Centric Service: Every client is assigned a dedicated project manager who acts as your single point of contact—providing daily production updates, addressing questions, and resolving issues within 24 hours. We offer 24/7 emergency service (for urgent projects like storm-damaged bridge repairs) and provide detailed documentation (material certificates, cut reports) for every order—critical for industries like aerospace and construction.