The basic salary in Shanghai is 3400 yuan. How much is the social security hardware?

It depends on where you are. In Shanghai, the insurance amount of social security payment base for 20 1 1 year is 2338. If the average monthly salary (or income in the first month) declared by your company in the previous year is 3,000, which is higher than 2,338, then you should pay it according to 3,000, and the unit burden is 3,000x37% =165438. If it is less than or equal to 2338, it shall be paid according to 2338, and the individual shall pay 2338X 1 1%=257.20.

If you are a person who transfers urban insurance to urban insurance, or a person who transfers comprehensive insurance to urban insurance, that is another matter. See:

Shanghai social insurance payment standard is 20 1 1 year.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.