Among which, core and cavity steel is the key.
For thin wall molds, especially under high speed high pressure injecting,
steel hardness must be HRC42 above, thus mold can guaranteed its lifetime.
NAK-80 or 718H, only with HRC30 above. No need to consider.
Even H13 is the basic steel for thin wall molds.
In additionally, raw material is clear transparent PP, it requires steel polishing property.
Above all, suggest S136 with HRC43-45.
If your budget limit, then suggest H13 with HRC43-45.
For more detail technicals, feel free to contact with me.
Welcome your new enquiry of thin wall molds!