Metal to use for new molder heater block

[brunneng]

I've been using the injection molder a bit and I've figured out what I want to change now to make it really usable.
One thing is to remake the heater block out of round stock so I can use standard band heaters and a nozzle heater. The block will be 3" dia and the nozzle will be 1" dia. The block will have a .5" bore for the piston.

Any suggestions for the metal for the heater block? It will get heated and cooled many times over use life to 500+ deg F.
I figure I want to use hot rolled although because I'm putting a small bore through a big block I don't figure I'd see any distortion with cold rolled.
Carbon or alloy steel? Would 12L14 be fine or should I use something more like 1141.

Thanks, any suggestions would be nice.

I'm also planning to add hydraulics for piston ram and mold clamp.

PS. Or maybe I should be asking about metals to stay well away from. I figured stainless was one for this.

[This message has been edited by brunneng (edited 06-10-2003).]

[Thrud]

Stainless would be my first choice.

12L14 should be avoided especially if the plastic will be used near food. Same for copper. Avoid anything toxic!

41xx would be ducky. You should be able to use nearly any metal, but make sure the piston and cylinder are made of the same material though...

[ulav8r]

H-13 is recommended for dies that are used hot, should be relatively easy to find. It is a very popular die steel that has similar strength to 4140HT.

<font face="Verdana, Arial" size="2">Originally posted by brunneng:
I've been using the injection molder a bit and I've figured out what I want to change now to make it really usable.
One thing is to remake the heater block out of round stock so I can use standard band heaters and a nozzle heater. The block will be 3" dia and the nozzle will be 1" dia. The block will have a .5" bore for the piston.

Any suggestions for the metal for the heater block? It will get heated and cooled many times over use life to 500+ deg F.
I figure I want to use hot rolled although because I'm putting a small bore through a big block I don't figure I'd see any distortion with cold rolled.
Carbon or alloy steel? Would 12L14 be fine or should I use something more like 1141.

Thanks, any suggestions would be nice.

I'm also planning to add hydraulics for piston ram and mold clamp.

PS. Or maybe I should be asking about metals to stay well away from. I figured stainless was one for this.

[This message has been edited by brunneng (edited 06-10-2003).]</font>

[brunneng]

Yep, same materials because we want the same rate of expansion, da?

I don't have plans for food items, but who knows so... what stainless would be the easiest to work, i.e. least workhardening. and should I look for annealed, stressproof, etc...?

[wierdscience]

Our local plastic pelletizing plants screws and barrels are made from 1045-1050,(they also use nitrobar the stuff they use for shock absorber shafts,I think you can find it on Baily fluid powers website) and usually nitrided and chrome plated.Thrud is also correct stainless would be a good choice but I would use something like nitronic 50 or similar because it is less likely to gall than the 304-316 alloys.They use the chrome on the parts for cleaning purposes and because it is slick and nothing sticks to it,you could also get the same advantages from polished stainless.Hope it works out