tap into

tap something into something

 and tap something in

to move something in with light blows. 

The mechanic tapped the bracket into place. 

The worker tapped in the bracket.

tap into

v.

1. To gain access to some resource: 

The building tapped into the city's water supply.

2. To take advantage of some sentiment: 

The politician tapped into voter anger 

and won the election.

to manage to use something in a way that brings good results:
If only we could tap into all that energy and creativity.

Meaning: Use or exploit a plentiful resource for your benefit

Example: The company is hoping to TAP INTO the Chinese market