When sourcing stainless steel components through investment casting (i.e., lost-wax casting), MOQ (Minimum Order Quantity) is one of the first questions engineers and procurement teams ask.
However, MOQ manufacturing isn’t just an arbitrary number set by the foundry. It is deeply tied to the production process, fixed operational costs, tooling requirements, and batch efficiency of the investment casting method.
This guide explains how MOQ works, why it matters, and how you can optimise it for your project, especially when working with precision metal components, such as SS304, SS316, and AISI 4140.
What Does MOQ Mean in Investment Casting?
MOQ refers to the minimum number of parts a foundry needs to produce in one batch to make the casting process technically and economically viable.
Unlike machining or 3D printing, investment casting involves a series of fixed-cost steps, such as:
- Wax tool preparation
- Shell building
- Melting and pouring
- Knock-out, cutting, and shot blasting
- Machining and finishing
These steps consume materials, labour, and production capacity, even if you only need a small number of parts. Therefore, MOQ is set to ensure the production batch remains cost-effective and operationally feasible.
Why Investment Casting Has MOQ Requirements
1. Melting & Pouring Require Minimum Alloy Volumes
Stainless steels such as SS304, SS316, and SS316L must be melted in controlled furnace batches.
A furnace cannot melt “just enough metal for 20 pieces”; it must melt a minimum charge to ensure:
- Correct temperature
- Proper chemical composition
- Stable metallurgical quality
This metallurgical limitation naturally drives MOQ requirements.
2. Fixed Production Costs Need to Be Amortised
Even small orders require:
- Tool setup and cleaning
- Wax injection preparation
- Shell room setup
- Casting simulation reviews
- Quality inspection and documentation
These fixed efforts are the same regardless of whether the order is 50pcs or 500pcs. MOQ ensures the cost per piece remains reasonable.
Typical MOQ Ranges in the Investment Casting Industry
Stainless steel investment casting, MOQ (Minimum Order Quantity) can vary significantly between projects. While many batches begin from a few hundred pieces, the required MOQ may increase depending on the part size, structural complexity, alloy selection, and the level of finishing involved.
MOQ is generally influenced by several key factors:
- Part size and weight
- Alloy type (e.g., SS304, SS316, SS316L)
- Ceramic shell thickness and casting stability requirements
- Post-casting and finishing processes
- Total annual usage (EAU) and production planning
This flexible, project-based method allows us to provide a MOQ recommendation that balances production efficiency, metallurgical quality, and cost considerations, supporting both early-stage development and long-term mass production.
Why Foundries Ask for Your EAU (Estimated Annual Usage)
MOQ manufacturing is not always a fixed number. It can be optimised if the foundry understands your estimated annual usage/demand.
If your EAU is high, suppliers can:
- Reserve furnace slots
- Pre-plan alloy batches
- Optimise tooling usage
- Reduce cost through economies of scale
This is why foundries often ask: “What is your expected EAU?”
It is not to lock you into long-term commitments, but to propose the most cost-efficient plan for your needs.
How Buyers Can Optimise MOQ (Without Overspending)
1. Share Forecast Volumes Early
Even rough forecasts help reduce:
- Unit cost
- Batch size
- Lead time
2. Group Variants Where Possible
If Var.A and Var.B share the same base tooling, MOQ can often be shared.
3. Consider a Dual-Cycle Strategy
For example:
- 1st batch: 300 pcs (for testing & market launch)
- 2nd batch: 700 pcs
- Combined EAU = 1,000 pcs (supplier optimises cost)
4. Choose a foundry with in-house tooling and vertically integrated operations
Like Waterson Corporation—this allows:
- Lower MOQ
- Faster development
- Better cost control
Compared to foundries that outsource tooling or machining, integration offers far more flexibility.
MOQ manufacturing at Waterson Corporation
At Waterson, MOQ is never a fixed figure. We evaluate each project individually, taking into consideration the part geometry, selected stainless steel grade, and your expected annual usage (EAU). This approach ensures that every batch is both technically feasible and cost-efficient. Waterson offers flexible and transparent MOQ plans to support global clients.
We optimise MOQ manufacturing based on:
- Part geometry
- Alloy type (SS304/316/316L)
- Annual usage (EAU)
- Project timeline
- Required surface finish and machining level
Send an RFQ to info@waterson.com with expected annual usage (EAU), and Waterson’s engineering team can recommend the most suitable MOQ and provide a detailed quotation.
Why Choose Waterson Investment Casting?
At Waterson Corporation, we don’t just offer competitive pricing, we deliver real value. Our expertise in precision investment casting is built on what matters most to today’s global buyers:
- Reliable part performance
- Dimensional accuracy
- Consistent quality
- Regulatory compliance(CBAM, RoHS, REACH )
We understand that in markets like the U.S. and EU, your casting supplier needs to meet more than just cost targets. You need a partner who supports your sustainability goals, provides full traceability, and helps reduce your total cost of ownership through dependable supply and technical support.
If you’re looking for a casting manufacturer that delivers long-term value, not just parts, we’re here to help.
Contact us at info@waterson.com to discuss your next project. Let’s build something better together!
Why Waterson Investment Casting Methods Stand Out
Waterson Corporation is a leading metal products manufacturer specializing in components for the most challenging global applications. Clients benefit from Waterson’s investment casting process, which excels in precision, durability, and surface quality—delivering unmatched reliability and performance across diverse applications.
- Precision Casting: Intricate, robust components for demanding industries.
- Superior Finish: Near-perfect surfaces with minimal processing.
- ISO 2768 Standard: Exceeds aerospace, marine, and petrochemical benchmarks.
- Versatile Materials: Tailored solutions in stainless steel and alloys with efficient material cost.
Waterson Stainless Steel Investment Casting Solutions
Waterson Precision Investment Casting is a wax-based foundry located in Taiwan specializing in stainless steel precision casting. It delivers high-volume, consistently high-quality castings to industries such as door hardware, petrochemicals, medical equipment, marine, hand tools, and food equipment. With an impressive 95% above self-production rate, Waterson’s production line encompasses mold design, fluid analysis, wax model creation, shell making, dewaxing, metal pouring, post-processing (e.g., acid pickling, alkaline treatment), sandblasting, heat treatment, machining, assembly, and packaging. Its stainless steel production line supports materials such as 304 (CF8), 316 (CF8M), and 17-4 stainless steel. Currently, there is available production capacity, feel free to contact info@waterson.com.
