Custom parts are not like off-the-shelf products. What you get depends heavily on what you specify, what your vendor understands, and what assumptions both sides are making. The engineers who ship on time and on budget are the ones who ask the right questions early.
About Cost
1. What is included in the quoted price?
Some quotes include material, machining, and finishing. Others exclude surface treatment, packaging, or shipping. Clarify what is and is not in the number before comparing vendors.
2. What design changes would reduce cost by 20% or more?
A good vendor should point out features that are expensive without being functionally necessary. If they cannot, you are likely paying more than you need to.
3. What is the price at 2x and 5x my current quantity?
Understanding per-part cost at different volumes helps you plan ahead and decide when to increase batch sizes.
About Lead Time
4. When does the lead time countdown start?
Is it from payment, from file approval, or from production start? The answer changes your actual delivery date significantly.
5. Is the material currently in stock?
If the vendor needs to source your material, your delivery date will slip. Ask this before placing the order.
6. What happens if the delivery is late?
Does the vendor take responsibility? Is there a refund or credit policy? If not, your timeline risk is entirely yours to absorb.
About Materials
7. Is my material selection optimal for this application?
Engineers sometimes over-specify materials for safety, which increases cost. Ask whether a lower-grade option would meet your functional requirements just as well.
8. Can I get a material certificate if required?
For regulated industries or critical applications, you may need documentation confirming material grade and properties. Not all vendors provide this by default.
About Quality
9. How are parts inspected before shipping?
Ask whether the vendor uses manual inspection, CMM measurement, or a basic visual check. For tight-tolerance parts, the inspection method matters a great deal.
10. What is the rejection rate for this type of part?
A vendor who knows their process should be able to tell you what percentage of similar parts pass on first inspection. If they cannot answer, that is a red flag.
11. What is your policy if parts arrive defective?
This is a non-negotiable question. The answer tells you exactly how much risk you are carrying with that vendor.
About the Process
12. Will you flag design issues before production starts?
Some vendors will machine exactly what you send, even if it will cause problems. Ask explicitly whether a DFM review is included in the process.
13. Who is doing the manufacturing and where?
This is especially relevant when using a platform or aggregator. Knowing the manufacturing location helps you assess quality, lead time, and traceability.
14. Can I get a first-article sample before full production?
For production orders above 50 units, a first-article inspection sample can save significant rework cost if something is wrong in the setup.
15. Can I reorder easily without resubmitting files?
Repeat ordering should not require starting from scratch. Ask whether your file history is maintained and whether repeat orders can be fulfilled with a single instruction.
ProtoMandi Answers All 15 Upfront
ProtoMandi is designed so engineers never have to chase answers. Transparent pricing breakdowns answer cost questions 1 through 3. Confirmed delivery timelines answer questions 4 through 6. Free DFM review answers question 12. The ProtoMandi Guarantee covers questions 9 through 11.
Your order history is saved for easy reorders. Our support team is available via WhatsApp and email for anything else. Order on ProtoMandi and go from questions to production without the back-and-forth.