The Tesla Model 3 will likely be constructed of a notable amount of aluminum, due to its minimal weight compared to steel.
We still don't know that ratio of aluminum to steel in the upcoming Tesla Model 3, but one can assume that, like other Tesla models, aluminum will be a critical component.
This assumption was strengthened by a report from Japanese news website, Nikkei, stating that a Japanese aluminum supplier for Tesla has ramped up production, and is setting future goals.
The company, UACJ, will invest ~$26 million into a company division that produces aluminum automotive parts for the Tesla Model 3. The goal of the investment is to boost production at its Michigan base by about 50 percent by December 2017.
Tesla has been explicitly clear with suppliers regarding timeline and expectations. The company has stated publicly that it can only be as successful as it weakest and slowest suppliers. This is, in part, a way for the company to steer blame when missing deadlines, but also read as a word of caution to suppliers. If a supplier isn't satisfying Tesla, the automaker will find another option.
With more news surfacing from Tesla's Q4 report yesterday (details) surrounding Fremont factory preparations, Model 3 pre-production that started this month, and a start of production in July, the "drop-dead" date is upon us.
Tesla has already nixed at least one supplier for not complying with its requirements. The automaker cancelled a $100-million order for axle drive pumps. Being that Tesla keeps much information private until the final moments, suppliers have to be proactive. In the event that Tesla Model 3 production meets the company's July 2017 goal, suppliers will have to be diligent to assure that production moves forward as planned.