Is AISI 1050 steel a good choice for making custom injection molds? I have
a client that received a very low quote for custom injection molds from a
Chinese source. I'm skeptical, so I asked a variety of questions including
the material that will be used. They answered with 1050 steel. I have been
searching for some information pertaining to 1050 and mold making, but it
doesn't seem to be commonly used for this purpose. Can anyone offer any
insights?
"Can anyone offer any insights?"
yes, getting involved in injection molding with:
very little (or no) injection molding experience,
a client who appears driven by price alone &
a vendor w/o a stellar track record
is a great way to REALLY learn the process by trial & error.
when it's all over you know a whole lot about injection molding
your situation has most, if not all, of the initial condtions for a
disaater
How many injection molded parts / molds have you been involved with?
I've done only a couple & my first thought would be hire a competent
tool maker to make the mold & give to a competent shop to make the
parts.
what material are you shooting?
desired / expected tool life (shots)?
single cavity? multiple? how many?
has this thing ever been made before?
successful mold making requires a competent mold designer and / or a
competent tool maker
you might be able to "contract" your way out of this by putting all the
risk on the mold mfr (esp) if they're the company doing the production
runs
progess payments for the mold dependent on producing XXX? good parts
tell your client
this............................................................
"the bitterness of poor quality is remembered long after the sweetness
of low price has faded"
cheers
Bob
Here's one of numerous listings for this mid carbon manganese
containing steel.
Because it is a carbon steel it is susceptible to heat treatment.
If you are talking plastic injection molds, there is no reason this
should not work quite well. Zinc alloys might demand more
consideration.
Brian Whatcott
BobK207,
Thanks for your input. I realize that my posting was very brief and failed
to provide much detail. The parts in question are generally ABS (one
acrylic and one PE) and range in size from a few inches to 30 inches. These
parts need to be high quality with good tolerances and nice, professional
surface finishes. The production volume isn't terribly high - about 10,000
pieces per year. Therefore, single cavity tools should be fine. Family
tools are appropriate for some of the similar parts. The tools should last
about ten years - so 100,000 minimum life. I would suggest a 500,000
lifetime guarantee. These are parts for a new product, so they have not
been made previously.
I have been working with injection molded parts for years and have worked
with a variety of reputable mold makers, including a few overseas. I am not
a mold designer or mold maker myself. My job is to design the parts, make
certain they can be molded without undue difficulty, and work with the mold
designer/maker to provide any necessary support. My current client has
received tooling and production quotes from a company I know nothing about,
but their pricing is surprisingly (unreasonably - in my opinion) low. This
concerns me a great deal, so I'm investigating their proposal. When asked,
they stated that all of the tooling would be made from 1050 steel. Since no
company I have ever worked with has even mentioned using 1050 steel, I
started looking for information. My references don't mention using 1050
steel for mold making and a web search produced one company in China that
uses 1050 for mold bases (inserts, etc. are made from other steels).
I am suspicious that using this low priced approach will lead to
unacceptable quality and/or unexpected costs. Of course, my instinct tells
me that this would be an enormous disaster as you have suggested.
Since my job is to provide technical knowledge and advice to my clients, I
am looking for clear technical reasons why using the cheapest sources is not
wise. So far, the argument that this pricing is
unreasonable/unbelievable/impossible has not been very convincing.
I am talking about plastic injection molding, primarily for ABS plastic
(also a little acrylic and PE).
I'm particularly concerned about the wear of such tools over time. My
general understanding is that tools made from cheap steels don't hold their
geometry as well as high quality steels. There may also be issues
pertaining to the process of making the tools, but I'm not an experienced
tool maker.
The following is a note I received from someone knowledgeable of tool making
and who has seen the parts in question.
1050 steel is what they call 45 steel in China. It is plain carbon steel
and is only used for inexpensive, non-critical parts or for low pressure
forming. Our factory will not use this material, for these molds especially
given the size and required clamping pressure on the larger parts. As I
have mentioned, we use 718 steel, which is imported from Switzerland. The
718 steel is in the same category as P-20 (40CrMnMo7) but it is a higher
grade tool steel than P-20.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.