Let’s talk about CNC part machining quotations today! Many people ask suppliers “How do you calculate the cost for machining?” right off the bat when looking for one. But when they receive the quotation, they’re confused—why is there such a big price difference between different manufacturers? ? Actually, there’s a lot that goes into a quotation; material costs, machining time, surface treatment, and more all need to be factored in. For example, the unit price of aluminum is different from that of stainless steel 304. Complex structures also require additional processes, which naturally increases the machining time.  

We’ve encountered some customers who only compared prices at first, chose the supplier with the lowest quote, but ended up with parts that didn’t meet precision requirements. Repeated rework eventually led to much higher costs. So, it’s not enough to just look at the quotation figure; you also need to check if the supplier uses appropriate equipment and has quality control measures in place. Some manufacturers will specify “tolerance within ±0.02mm”—even though the unit price is slightly higher, it saves you trouble later on.  

By the way, here’s a reminder: never overlook surface treatment! The price difference between including or excluding processes like anodizing and electroplating is quite significant. There was once a customer who skipped sandblasting to save money, only to find the parts rusting not long after installation… ? So, you need to clarify every item on the quotation and not just focus on the total price.  

A common question I get is: “Why is the unit price higher for small-batch orders?” Actually, this has to do with production line adjustments—CNC machines take time to change materials and program. When the batch size is larger, the average cost is spread out. If you only need one or two pieces, it’s reasonable for the manufacturer to charge a setup fee.  

Finally, here’s a practical tip for you: if you want to get an accurate quote, it’s best to provide 3D drawings directly (STEP/IGS formats are both acceptable), and clearly state the material and requirements. This way, the supplier can calculate the cost accurately and avoid price increases later! ? I hope this experience helps you. If you have any questions, feel free to leave a comment below~