---
title: mass
framework: quartzcore
role: symbol
role_heading: Instance Property
path: quartzcore/caspringanimation/mass
---

# mass

The mass of the object attached to the end of the spring.

## Declaration

```swift
var mass: CGFloat { get set }
```

## Discussion

Discussion The default mass is 1. Increasing this value will increase the spring effect: the attached object will be subject to more oscillations and greater overshoot, resulting in an increased settlingDuration. Decreasing the mass will reduce the spring effect: there will be fewer oscillations and a reduced overshoot, resulting in a decreased settlingDuration.

## See Also

### Configuring Physical Attributes

- [damping](quartzcore/caspringanimation/damping.md)
- [initialVelocity](quartzcore/caspringanimation/initialvelocity.md)
- [settlingDuration](quartzcore/caspringanimation/settlingduration.md)
- [stiffness](quartzcore/caspringanimation/stiffness.md)