Q. In door shutters, the type of the spring used is (Solved)
1. spiral spring
2. helical torsion spring
3. Cast steel
4. close coiled helical spring
5. conical helical spring
- b. helical torsion spring
1. spiral spring
2. helical torsion spring
3. Cast steel
4. close coiled helical spring
5. conical helical spring