Normally all the performance testing tools that are used for load testing could also be used for stress testing. Below mentioned are the ones that are most commonly used:
Loadrunner from HP is the widely used tool to perform stress testing and the results provided by Loadrunner are considered as a benchmark.
It is an open source tool that is available free of charge. It is a Java application and is intended to conduct all performance testing types including stress testing.
This tool is used to perform stress testing on web as well as mobile applications. It has numerous advantages like it supports all major servers available in the market, could be used to conduct stress testing on ERP, CRM, and Business Intelligence type applications etc.