Why are bumper plates 450 mm in diameter?
450 mm is the standard diameter for competition discs from 10 kg upwards, so a loaded bar always starts at the same height off the platform, whatever the weight. That keeps the start position the same for every lifter and every attempt.
| Werksan disc | Diameter | Thickness |
|---|---|---|
| 25 kg (IWFCP25, LBD25) | 450 mm | 63 mm |
| 20 kg (IWFCP20, LBD20) | 450 mm | 53 mm |
| 15 kg (IWFCP15, LBD15) | 450 mm | 42 mm |
| 10 kg (IWFCP10, LBD10) | 450 mm | 32 mm |
| 5 kg technique (IWFTED5) | 450 mm | 100 mm |
What changes with weight
- Thickness, not diameter: heavier discs are thicker, from 32 mm at 10 kg to 63 mm at 25 kg.
- Same bar height: the pull always starts from the same position.
Why it matters for beginners
- Technique discs are full size too: the 5 kg IWFTED5 and 2.5 kg IWFTED250 are 450 mm, so beginners learn from the correct height with very little weight.
Common questions
Are change plates 450 mm?
No. Change plates from 0.5 to 5 kg are smaller, and are loaded inside the large discs.
Do LionFit plates match competition discs?
Yes. LionFit bumpers share the 450 mm diameter and the same thicknesses.