I am working on a project that need to redesign a sewing needle. Because I am planning to use a stainless steel loop to replace a needle's eye, using high carbon steel, which make all modern needles, would not be industrially profitable as it is hard to weld and might take a lot of time. I am wondering is there other material that can replace high carbon steel as the raw material for a needle? Or, is there other materials soft enough to be bented into any shape and can be joint with high carbon steel or whatever material that can replace it? Thanks a lot!
There are a large number of stainless steels which are hardenable and can be used as a more or less direct replacement for high carbon steel. Common grades like 304 and 316 would be possible candidates and 440 is widely used for cutting tools.
Needles are typically made by drawing form wire stock and punching the eye so welding or other jointing processes are not required unless there is a very specific reason why you want it made from two separate materials.
It is also worth mentioning that without more details of what you are planning to achieve it is hard to give more specific recommendations. Obviously needles have been around for a very long time and as such there is limited scope for improvement unless you have a new and different application.