When requesting a quotation for a magnetic coupling, many buyers provide only a drawing size or a target torque. In practice, this is often not enough for an accurate evaluation.
A magnetic coupling is a customized magnetic assembly. Its design depends not only on dimensions, but also on working conditions, speed, gap, temperature, containment can structure, and acceptance requirements. If key information is missing, quotation and technical communication usually become slower and less accurate.
This article provides a practical magnetic coupling RFQ checklist for OEM buyers and engineers. It helps you define the most important inputs before sending an inquiry, so suppliers can respond more efficiently and proposals can be compared more clearly.
If you would also like to understand the basic principle and common types, you can read our related article:
Magnetic Couplings: Working Principle, Types and Applications
Why a Clear RFQ Matters
A better RFQ helps in three ways:
- reduces repeated communication
- improves quotation accuracy
- shortens project lead time
For magnetic coupling projects, the supplier usually needs to evaluate not only the magnetic design, but also the mechanical structure and the real operating conditions. A clear RFQ makes that process much more efficient.
1. Torque Requirement
Torque is the first key parameter, but it should be clearly defined.
Please confirm:
- continuous working torque
- startup torque
- peak torque
- whether there is any stall / overload condition
These values should be given with units, usually N·m.
Why it matters
A single torque number may not fully represent the actual load condition. A coupling may work well under continuous torque, but fail under startup shock load or temporary overload if those conditions were not included in the design review.
2. Speed and Duty Cycle
Please provide:
- normal operating speed
- maximum speed
- start/stop frequency
- whether the system runs continuously or intermittently
- whether reverse rotation is involved
Why it matters
Magnetic coupling performance is closely related to rotational speed and duty cycle. These conditions also affect temperature rise, stability, and design margin.
3. Gap and Installation Space
Please clarify:
- radial or axial structure
- available outside diameter / inside diameter / length
- working gap or clearance
- shaft connection dimensions
- general installation drawing if available
Why it matters
In magnetic couplings, gap directly affects torque transmission capability. Even a small change in gap may lead to a big change in performance. A clear installation envelope also helps the supplier evaluate whether the proposed structure is practical.
4. Containment Can / Isolation Sleeve Requirements
If your project uses a sealed structure, please specify:
- whether a containment can is required
- material of the can
- thickness
- pressure condition
- medium inside the system
- corrosion or chemical compatibility requirements
Why it matters
The containment can is not only a mechanical part. Its material and thickness may affect magnetic performance, eddy current loss, and heat generation. This is especially important in pump, chemical, and sealed mixing applications.
5. Operating Temperature
Please provide:
- ambient temperature
- media temperature
- expected continuous temperature
- temporary peak temperature, if any
Why it matters
Magnet material selection depends heavily on temperature. If temperature is not defined clearly, the selected magnetic grade may not be suitable for long-term operation.
For example, standard NdFeB grades may not be enough for higher-temperature applications, while higher temperature grades or other magnetic materials may need to be considered.
6. Mechanical Constraints and Alignment Conditions
Please confirm:
- fixed dimensional limits
- shaft alignment condition
- runout tolerance if applicable
- bearing support condition
- whether rotor balance is required
Why it matters
A magnetic coupling is not only a magnetic product. It is also a mechanical assembly. Alignment, runout, and structural constraints can affect actual operating stability and service life.
7. Acceptance Criteria and Supply Scope
Before quotation or sample approval, it is useful to define:
- prototype quantity
- production quantity or annual demand
- sample evaluation method
- requested test items
- drawing revision
- delivery target
- which parts are included in supply scope
Why it matters
A clear acceptance standard reduces misunderstanding later. It also helps both sides define responsibilities before production starts.
Simple Magnetic Coupling RFQ Checklist
Before sending your inquiry, it is recommended to confirm the following 7 items:
- Torque requirement
- Speed and duty cycle
- Gap and installation space
- Containment can requirements
- Operating temperature
- Mechanical constraints and alignment
- Acceptance criteria and supply scope
If some information is still unknown, that is acceptable. The important point is to clearly state which parameters are fixed and which still need supplier recommendation.
A Practical Suggestion for OEM Buyers
If your application is still in the early design stage, you do not need to provide every internal magnetic detail at the beginning. In most cases, the more practical approach is to provide:
- your target torque
- speed range
- available installation space
- temperature condition
- containment can requirement
- application environment
With this information, an experienced supplier can first evaluate feasibility and then discuss the optimized structure step by step.
This approach is usually more efficient than trying to define every magnetic design detail too early.
Conclusion
A magnetic coupling quotation becomes much more accurate when the RFQ is based on real operating conditions rather than only dimensions.
A clear checklist helps both buyer and supplier communicate more professionally, efficiently, and directly. It also reduces unnecessary revision during design and sampling.
At Guande Magnet, we support OEM customers in custom magnetic coupling projects based on actual application requirements.
If you are working on a new project, feel free to share your drawings or key technical parameters with us for evaluation.
Related product page:
Magnetic Couplings
