Which difference astm a53 and astm a106

Which difference  astm a53 and astm a106

For example when we compare between A106-B and A53-B seamless from chemical composition point of view, we find that :
1. A106-B contains silicon, min. 0.10% where A53-B has zero%, and silicon is the important element for improving the heat resistance criteria.
2. A106-B contains manganese 0.29-1.06%, where A53-B 1.2%.
3. A106-B contains low sulfur and phosphorus, max. 0.035% where A53-B contains 0.05 and 0.045% respectively.