In last few rumors we could hear that Apple is giving up on metal design on its iPhone lineup and will be replacing it with Samsung-like glass design.
It's also well known that'll device feature a metal frame beetwen front and rear glass, creating so called ''sandwich design".
What is not clear is what kind of material will be used for frame, but according to leaks it might be stainless steel.
Stainless steel was also used in iPhone 4 and companies that were making frame for iPhone 4, will be making it again for iPhone 8.
Companies are Foxconn and Jubil and cost of making these frames for Apple will be 30-50% cheaper than current aluminum unibody CNC machining process.
All money saved by making frames can be wisely used for purchasing those often rumored curved AMOLED displays from Samsung, as they are a more expensive than LCD's.
For now,three companies are assembling next iPhone: Foxconn, Pegatron and Wistron.