Q&A: Plastic injection mold – cost estimate?
June 29th, 2010 | 
Author: Question by Skt: Plastic injection mold – cost estimate?
I think most of you would have seen the SD-card case, the clear plastic one, ~ 2″ x 1.5″ x 0.5″. I don’t know if I can post web links, here is one sample image,
http://www.inanycase.com/Merchant2/graphics/00000001/SDMMC-Card-Case0405_thumb.jpg
Can any one give me a ballpark number for how much the injection molding would cost for a product like that? In the US vs in China?
Thanks.
Best answer:
Answer by tinkertailorcandlestickmaker
High production multi-cavity hardened steel, or low production, single cavity aluminum (or maybe even epoxy)?
Since cases are already available, I’m guessing you might want a limited run with a special logo for some promotional use. But then again you ask about China…
I don’t really know, but I’d guess several thousand for the first case, and a few to several hundred for the second case (US dollars)
But if you can sell the cases for .33 each (3 for .99) you should get your money back pretty quick. Of course that is a really big IF, I wonder if inanycase.com has ever sold any of those cases at that price? that seems insanely high. I could believe 12 for .99 (not that anyone would need 12, since most cards come in a case to start with)
What do you think? Answer below!
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It’s more important that YOU define the volume of units you plan to sell.
The number of units drive the number of cavities. You also need to define the material to be used (an Electro-Static Dissapative plastic? if you’re worried about static damage to the SD card), or perhaps poly-propylene if you’re not?
The way the Chinese manufacturers work is that you state how many units you want, any other specs on your drawing, and they will quote you the per part price (usually in quantity 10,000 or more). They will take care of all the mold costs and not bother you with them; also, they will own the mold. I’d guess not less than 40 cents each, delivered, in quantity 10k+.
If you order 100,000 or more, then the cost goes down to approximately the cost of plastic material. To do it right, you’d have to research the cost of plastic in China (they make their own; they don’t buy from the US).
The US typically conducts business somewhat differently – you buy/own the mold, and the molder will charge you per-piece. Figure 30 sec cycle time (that’s two parts per minute) times $100/hr shop rate, and you get $100/120 parts = $0.83/part + cost of plastic. Simple molds like yours run in the $3000 to $8000 range, depending on how many parts you want. If the mold wears out or gets damaged, you own the mold, so you have to pay for repair/replacement.
Fundamentally, your larger problem is marketing – how many of these units can you realistically sell?