Part of our Complete Guide to Wire Arc Additive Manufacturing →
Why is WAAM better than casting and forging?
Wire Arc Additive Manufacturing (WAAM) is a technology used for printing metal to achieve stronger, faster, and more sustainable parts to meet the needs of businesses and industries worldwide needing a reliable, efficient, and scalable printing solution, 24/7, and a fully-controlled and monitored project workflow and printing process. Doing things faster is a pivotal aspect where WAAM wins over casting and forging methods, which are more traditional methods for additive manufacturing. Since WAAM eliminates the need for dedicated tooling and long lead times almost completely, it can deliver functional metal parts in days rather than weeks, dramatically accelerating prototyping, time-to-market, and on-site repairs.
Furthermore, WAAM offers significant advantages in scenarios where traditional manufacturing methods struggle with costs, lead times, or flexibility. For example, we have printed a Bronze Impeller much faster and more precise than others would have achieved with casting or forging methods. Regarding lead times, the bronze impeller project final results, thanks to the fact that it has been printed with WAAM technology, granted a very fast printing, achieving and providing a much shorter timeframe, and consequently a short lead time. Speaking of numbers, the WAAM print timeframe for this project has been equivalent to one month, unlike the lead times that are common with casting and forging methods, which correspond to 6-8 months. Businesses know how important time-saving procedures are, especially when it comes to project delivery, capital investment, and subsequent steps aimed to avoid useless overviews and complexity, which can all be solved by using WAAM technology and the dedicated MetalXL software .
When to use additive manufacturing and choosing the best technology?
Wire Arc Additive Manufacturing can deliver a first article in 2 to 4 weeks, while sand casting typically requires 16 to 24 weeks for tooling, casting, cleaning, and machining (depending on the part). When the cost of downtime exceeds the cost of manufacturing, WAAM becomes the most economical option. This cost-saving reasoning applies especially for businesses that need continuous and constant printing, as this printing method guarantees a decidedly significant time-saving and money-saving outcome, and turns out to be the best solution for the majority of printing projects.
Even if we are aware that traditional methods can be used for specific projects or requests, WAAM technology remains a decidedly more efficient, flexible, and effective solution. This flexibility and adaptability of the technology are key points in the decision to choose this printing method for complex projects and geometries. WAAM allows businesses to ace their printing requests in certain situations, to obtain the printing of complex parts with a decidedly greater precision and less material waste, all characteristics with a continuity in the workflow that other methods cannot guarantee, also thanks to the possibility of printing on multiple axes and above all of being able to print 24 hours a day, by controlling everything via our advanced MetaXL WAAM dedicated software.
The software guarantees full control of all the parameters and workflow, while enabling the personalization and tailoring of all the process settings and printing steps necessary to guarantee a clean, precise, and efficient print from the moment the printing process is started via software. achieves enhanced performance and productivity through dynamic sensors for continuous control and monitoring.
WAAM vs Casting vs Forging: Side-by-Side Comparison
The following tables summarize the most important differences between WAAM and traditional manufacturing processes. These values reflect typical MX3D performance and industry norms, quality, and production standards.
Table 1
| Factor | WAAM (Wire Arc AM) | Sand Casting | Investment Casting | Forging |
|---|---|---|---|---|
| Lead time (1st article) | 2 to 4 weeks | 10 to 16 weeks | 12 to 20 weeks | 14 to 24 weeks |
| Tooling required | None | Patterns and molds | Wax patterns and ceramic molds | This |
| Tooling cost | €0 | €8K to €60K | €15K to €120K | €60K to €500K |
| Minimum order quantity | 1 | 10 to 50 | 50 to 100 | |
| Part size range | Up to 6.5 meters | Up to 5 meters | Up to 1 meter | Up to 3 meters |
| Deposition rate | 3 to 12 kg per hour (steel) | Not applicable | Not applicable | Not applicable |
| Material utilization | 85 to 92 percent | 60 to 70 percent | 85 to 95 percent | 50 to 60 percent |
Table 2
| Factor | WAAM (Wire Arc AM) | Sand Casting | Investment Casting | Forging |
|---|---|---|---|---|
| Surface finish (as produced) | Ra 30 to 45 micrometers | Ra 12 to 25 micrometers | Ra 3 to 6 micrometers | Ra 6 to 12 micrometers |
| Mechanical properties | Comparable to wrought or forged after heat treatment | Lower than wrought | Variable | Excellent due to grain flow |
| Design change cost | Software update only | New patterns and molds | New wax and ceramic tooling | New dies |
| Post processing | CNC machining and heat treatment | Cleaning and machining | Minimal machining | Machining |
| Best for | Low volume, large parts, rapid delivery | Medium to high volume, complex shapes | High precision, small to medium parts | High strength structural parts |
These values represent typical performance. Actual results vary depending on geometry, material grade, and certification requirements.
When to Choose WAAM Over Casting or Forging (WAAM vs Forging & Casting Decision Guide)
WAAM Materials: large availability and adaptability
When it comes to materials we can use to print with this technology , another very positive aspect of WAAM is that this printing technique can practically be chosen to print with any type of welding wire, such as alloys. The materials are evaluated and picked to provide high levels of quality by following certification standards, granting efficiency, and solidity, ensuring the printed part’s overall quality and durability in the various materials available. The widely available welding wires and the continuous printing process, with no separate parts fusion, layer after layer, make sure the final printed part is fully operational and ready to be used for the designated purposes.
Low Volume or One-Off Production
Another important aspect for which WAAM technology is superior to other methods and provides faster lead times is the fact that it does not require dies and molds, and therefore it is more straightforward in terms of the steps needed to start printing and to monitor it. One example of the application of this technology and its benefits is our Bronze impeller project, which will be discussed further within the text. The fact that this method does not require molds allows for reduced material waste and, therefore, a reduction in overall costs for the project, leading to a more wise usage of the materials and resources for each printed part.
Another perk is that WAAM eliminates tooling, while casting requires patterns and molds, and forging requires dies, and these tools must be designed, manufactured, and validated before the first part can be produced. The less need for the initial part or additional test and gears, also leads to a lot less material waste and CNC (milling) required. For quantities between one and ten parts, WAAM typically provides the lowest total cost because there is no tooling to amortize, and represents the option businesses have to opt for.
In addition, the cost curve for WAAM is relatively variable as man-hours, machining time, and printing time are all influenced by the material choice, geometry, and complexity of the printed part. The cost per part remains consistent because the process is driven by deposition time, machining time, and material usage. Casting begins with a high initial cost due to tooling, but the cost per part decreases rapidly as volume increases. Concerning typical MX3D components, break-even between WAAM and casting occurs between 15 and 40 parts, depending on geometry and complexity.
Obsolete Parts with No Existing Tooling: WAAM is the solution to this matter
Many legacy systems rely on components for which the original molds or dies no longer exist. Recreating tooling for a single replacement part is rarely cost-effective. WAAM enables production directly from 2D drawings or 3D scans, making it ideal for defense equipment, power generation turbines, maritime propulsion systems, and industrial machinery with long service life. Reverse engineering combined with WAAM provides a practical path to restoring obsolete components without the need for expensive tooling recreation.
Design Iteration and Prototyping
WAAM allows engineers to modify designs without incurring new tooling costs. The cost-saving part is that a design change requires only a software update, and this makes WAAM particularly effective for prototyping large metal components, testing multiple design variations and complexity, iterating on topology-optimized structures, and validating manufacturability before committing to casting or forging.
This technology changes the production timeline and cost structure of large metal components by removing many of the constraints built into conventional methods. Instead of relying on molds, dies, or long lead‑time tooling, WAAM builds parts directly from digital models, which shortens development cycles and opens up new design possibilities.
Repetitiveness, blueprint generation, printing speed, and geometry freedom with WAAM
Repetitive parts can be streamlined wth WAAM by creating a single blueprint and reusing it throughout the process, eliminating the need to repeat testing and other redundant steps. This approach becomes even more valuable when working with geometry-heavy designs, as it enables the production of more complex components in a single print. Instead of manufacturing multiple cast or forged pieces and welding them together, the entire structure can be produced as one integrated part, improving efficiency, precision, and overall structural integrity.
Furthermore, with WAAM Systems, such as with MX3D Metal AM M1 and MX Systems , can print multiple layers continuously without having to weld and separate parts. This pivotal aspect of the technology makes the projects workflow more controllable, fast and makes the parts’ geometry way more solid, resistant and detailed, also eliminating unpleasant effects and imperfections such as the presence of bubbles that could occur using other traditional methods, such as casting and forging, due to the union of different pieces that are fused while being in contact with the air.
Thanks to the expertise and trackable, clean, and trustworthy cases tied up with extensive research & development, MX3D WAAM technology unlocks new possibilities for different businesses and industries when looking for a reliable supplier for a final printed product with fast lead time, less material waste, more control over the entire process, and more details.
Printing Geometry: MX3D projects delivered with different challenges and complexity, but the same WAAM technology
On one hand, an example of a fast and durable geometry print that MX3D has performed is the bronze impeller project . The impeller print is one of the clearest demonstrations of how WAAM technology shifts the boundaries of what is possible in industrial manufacturing and represents a turnkey solution.
We produced a 350-kilogram nickel-aluminum bronze impeller for ENGIE’s Amercoeur power plant, a part that would traditionally require 6 to 8 months of casting lead time. With robotic WAAM, the entire component was printed in 9 days, achieving an average deposition rate of 3.2 kilograms per hour while using multiple qualified parameter sets. The program began with extensive material and parameter validation on test plates to ensure mechanical performance and repeatability, which is essential for a safety‑critical rotating component. Once validated, the WAAM process delivered a near-net-shape geometry with drastically reduced material waste and a fully traceable digital build record. This case is significant not only because of the scale and complexity of the part, but because it represents one of the first operational installations of a large, critical WAAM‑manufactured component in the energy sector. It shows how WAAM can compress lead times, reduce dependency on casting tooling, and enable rapid production of mission-critical components that would otherwise be bottlenecked by traditional supply chains.
On the other hand, an example of complex geometry made possible by WAAM technology is the BMW Automotive project, with which MX3D collaborated on printing a suspension strut support system in a single run. The result speaks for itself: faster delivery times, stronger geometry, and a leaner supply chain. Even if these parts presented a high-complexity and multiple-axis printing was needed, it was managed without any kind of problem by MX3D Metal AM M Systems and the MetalXL WAAM software, and thanks to the expertise and cost-efficient materials usage applied.
BMW Group demonstrated that WAAM can measure automotive serial quality by using an M1 system and MX3D’s MetalXL workflow to produce structural components that achieve the required cyclic load performance without full surface post-processing. Careful development of welding parameters, robot path planning, and process monitoring produced parts that were both lighter and stiffer than comparable die cast components while reducing material waste and energy use. The program combined targeted metallurgical validation, in-process traceability, and selective finishing to deliver repeatable mechanical performance at scale, showing that WAAM can move from prototyping into production for demanding automotive applications.
WAAM vs Casting vs Forging comparison: where WAAM technology wins
- WAAM (Wire Arc Additive Manufacturing) typically delivers parts within a matter of weeks. Traditional casting or forging often requires several months because of tooling design, mold fabrication, and iterative adjustments before production can even begin.
- WAAM eliminates the need for dedicated tooling. Conventional processes depend on expensive molds and dies that take significant time and money to produce, especially for large or complex geometries.
- WAAM deposits material only where it is needed, achieving near-net-shape builds with material utilization around 90%. Casting and forging usually require extensive machining afterwards, which generates substantial scrap and increases both cost and environmental impact.
- WAAM supports geometries and complexity that are difficult or impossible to achieve with molds, such as hollow sections, internal features, or topology‑optimized structures. Traditional methods are limited by mold parting lines, draft angles, and other geometric constraints.
While casting and forging can represent an ideal option compared to WAAM in several specific technical and economic dimensions, WAAM can represent the best printing option when it comes to some applications and features. In particular, the WAAM vs forging comparison favors WAAM whenever tooling lead time and upfront die costs outweigh unit-price savings.
WAAM vs Casting/forging: a quick comparison scenario
| Challenge | Why casting/forging wins | When WAAM still works |
| High-volume identical parts | Low cost per part after tooling amortization | Shorter lead time for first batches; ideal for evolving designs or pilot runs |
| Exceptional surface finish | Investment casting yields Ra 3–6 μm as cast | WAAM + targeted CNC finishing reduces total machining for large, non-critical surfaces |
| Thin walls / fine features | Casting and powder bed fusion handle sub-mm detail | WAAM suits medium/large parts; combine with machining or cast inserts for fine features |
High-volume production (100+ identical parts)
For long, stable production runs where tooling costs are spread across many units, casting and forging usually deliver the lowest unit cost and predictable cycle times. WAAM can still be a practical choice early in the program because it eliminates tooling lead time and sunk costs, enabling rapid prototyping, pilot batches, and design validation before committing to dies or molds. In situations where demand is uncertain or designs will evolve, using WAAM for the first several dozen parts to a few hundred parts can reduce risk and cash outlay while the business case for traditional tooling is confirmed. Even when volumes eventually favor casting or forging, a hybrid path, WAAM for initial runs, then transfer to casting/forging, often shortens time to market and lowers overall program risk.
Parts requiring exceptional surface finish
Investment casting and forging produce fine as‑cast surfaces that minimize downstream machining for many functional faces. WAAM parts typically require more surface finishing to reach Ra values comparable to investment casting, but that does not preclude their use: by combining targeted CNC finishing on critical surfaces with as‑printed noncritical areas, WAAM can meet functional requirements while saving machining time on the whole part. Additional post‑processing, such as localized milling, shot peening, or surface coatings, can bring key features into tolerance without reworking the entire component. For applications where only a few faces demand a tight finish, WAAM plus selective finishing can be an efficient compromise.
Thin-walled or ultra-fine features
WAAM’s bead geometry and process constraints make sub‑millimeter walls and intricate internal channels challenging to print directly, so investment casting and powder bed fusion remain better suited for those fine details. WAAM remains viable by shifting the design approach: print the large structural volume with WAAM and incorporate thin‑walled inserts, cast subcomponents, or PBF‑produced modules for the delicate features. Alternatively, machine thin sections from printed stock or add brazed or bolted sleeves where needed, preserving WAAM’s advantages for size and strength while delegating ultra‑fine geometry to processes optimized for it.
Broader advantages that tip the balance toward WAAM in many real projects
WAAM’s strengths, rapid iteration, low upfront tooling cost, ability to produce very large parts, and excellent suitability for repair and refurbishment, make it the right choice in many real-world scenarios, even when traditional methods outperform it on specific metrics. For large structural components beyond casting or PBF size limits, for on‑site repairs that avoid part removal and long logistics chains, or for programs that prioritize speed and flexibility over absolute unit cost at scale, WAAM often provides decisive value. Combining WAAM with targeted machining, inserts, or hybrid assemblies lets teams capture the best of both worlds: the geometric and economic benefits of additive manufacturing alongside the surface quality and fine detail of traditional processes.
WAAM vs. Casting/Forging: Real Project Data (MX3D Impeller project)
The following comparison highlights and demonstrates the typical advantages of WAAM for low-volume, high-value components where tooling cost and lead time dominate the decision. Whether the question is WAAM vs forging or WAAM vs casting, the data below shows the perks, the lesser time needed, and cost-saving outcomes obtainable by using WAAM instead of traditional manufacturing methods.
| Factor | WAAM (Printed Impeller Project) | Traditional Casting/Forging | Improvement |
|---|---|---|---|
| Lead Time | 1 month | 6-8 months | ≈83-87% faster |
| Tooling / Molds | None required | High‑cost molds + long tooling phase | 100% tooling elimination |
| Material Waste | Near-net shape (~10-20% waste) | Heavy machining + gating (50-90% waste) | ≈60-80% less waste |
| Cost | No molds, reduced machining; typical WAAM savings 30–50% | High tooling cost + long machining | ≈30-50% cost reduction |
| Design Flexibility | Complex, hollow, optimized geometries are possible | Limited by mold geometry | Major increase in design freedom |
When Traditional Manufacturing Is Still Better
Casting and forging remain essential manufacturing methods. They represent a more suitable choice than WAAM in some scenarios.
High Volume Production of 100 or More Identical Parts
Once tooling is amortized across hundreds of parts, casting becomes significantly more cost-effective than WAAM. For serial production, casting combined with CNC machining typically delivers the lowest cost per part. Forging also becomes highly competitive for high-strength components produced in large quantities.
Parts Requiring Exceptional Surface Finish
Investment casting achieves surface roughness values of Ra 3 to 6 micrometers as cast. WAAM produces Ra 30 to 45 micrometers and requires CNC machining for any functional surface. If a component requires tight tolerances on all surfaces, the machining effort for WAAM may exceed the benefit of near-net shape production. In these cases, investment casting or forging is more efficient.
Thin-Walled or Ultra-Fine Features
WAAM has a minimum wall thickness of approximately 5 millimeters. It is not suitable for sub-millimeter features or intricate internal channels. Investment casting and powder bed fusion excel in these areas. WAAM is best suited for medium to large parts with moderate geometric complexity.
The Best of Both Worlds: Hybrid Manufacturing
Hybrid manufacturing combines WAAM with traditional processes to achieve optimal performance and cost efficiency. WAAM can be used to add features to cast or forged base parts. This is particularly useful for large flanges, valve bodies, structural nodes, and pressure retaining components.
WAAM is also effective for repairing or refurbishing existing cast or forged components. Material can be added precisely where needed, extending the service life of high-value parts.
Another hybrid strategy is to use WAAM for prototyping and early production, then transition to casting for high-volume manufacturing once the design is finalized. This reduces risk and accelerates time to market.
Case Study: WAAM vs Casting and WAAM vs Forging in Practice
The following case study illustrates the real-world impact of WAAM compared to traditional casting. These values are representative of typical MX3D project outcomes.
| Metric | Traditional (Casting) | MX3D WAAM |
|---|---|---|
| Part | Stainless steel pump impeller | Same part |
| Material | 316L | 316L |
| Lead time | 18 weeks | 3.5 weeks |
| Tooling | €32,000 for patterns | €0 |
| Material waste | 62 percent | 14 percent |
| Metric | Traditional (Casting) | MX3D WAAM |
|---|---|---|
| Mechanical properties | UTS 520 MPa | UTS 610 MPa after heat treatment |
This comparison demonstrates the typical advantages of WAAM for low-volume, high-value components where tooling cost and lead time dominate the decision.
Frequently Asked Questions (FAQ)
Is WAAM stronger than casting and forging?
WAAM parts can match or exceed the mechanical properties of cast components, and the WAAM vs forging comparison is equally compelling for many alloys. MX3D WAAM 316L typically achieves ultimate tensile strength values between 600 and 650 MPa after heat treatment, compared to approximately 520 MPa for cast 316L. Actual performance depends on material grade, process parameters, and post-processing.
Is WAAM cheaper than casting and forging?
For quantities between one and ten parts, WAAM is typically cheaper because it requires no tooling investment. The WAAM vs forging cost advantage is especially clear for low-volume runs, since forging dies can cost €60K to €500K. For quantities above fifty identical parts, casting becomes more cost-effective due to tooling amortization. The break-even point for typical MX3D components is between 15 and 40 parts.
Can WAAM parts be certified to the same standards as cast parts?
Yes. MX3D WAAM parts are certified to DNV, ASME, PED, and API 20S standards . These are the same certifications required for cast and forged components in energy, maritime, and defense applications.
What surface finish does WAAM produce?
WAAM produces a near net shape part with surface roughness between Ra 30 and 45 micrometers. Most applications require CNC machining for functional surfaces. MX3D typically builds with 2 to 3 millimeters of machining stock.
