Home / Equipment / Ball Specs / Purple Pearl Urethane
Hammer · ball specs
Hammer Purple Pearl Urethane specs
The Hammer Purple Pearl Urethane is a urethane ball with the LED core. Here are its published specs, how they compare with the other current balls in our table, and what the numbers mean on the lane.
Disclosure: this page has affiliate links. If you buy through them, we may earn a commission at no extra cost to you. As an Amazon Associate we earn from qualifying purchases. How this works.
| Coverstock | Urethane Pearl |
|---|---|
| Cover type | Urethane |
| Core (weight block) | LED |
| Core type | Symmetric |
| RG | 2.650 |
| Differential | 0.015 |
| Factory finish | 500, 1000, 2000 Siaair Micro Pad |
| Maker's category | Mid Performance |
| Color | Purple Pearl |
| Weights | 16-12 Pounds |
| Release date (maker) | July 1, 2021 |
Numbers as Hammer publishes them, checked 21 October 2026. Published for a 15-pound ball. Drilling changes how a ball behaves, so a pro shop's layout matters as much as these numbers.
Find the Purple Pearl Urethane on Amazon → Compare with another ball Add to my arsenal
What the numbers mean
RG 2.650. That is lower than 1% of the 134 current reactive and urethane balls in our table, so it sits on the high side. Storm says "a high RG ball delays its revving, offering more length and angular motion down the lane."
Differential 0.015. Higher than 2% of the balls in our table. Storm says "a low differential ball tends to have a more predictable, controlled motion."
Urethane cover. Storm says urethane covers "displace oil rather than absorbing it" and are a popular choice for spares and shorter oil patterns.
Symmetric core. Storm says symmetric balls have "RG values consistent across all axes" and a smooth, predictable roll.
USBC allows an RG from 2.447 to 2.813 inches and a differential of at most 0.060 inches (Equipment Specifications Manual, March 2026). Our ball spec table lists every current ball we track, and who makes bowling balls covers which company owns Hammer.
Balls with similar numbers
Same cover type, closest RG and differential in our table:
- Hammer Black Pearl Urethane: RG 2.650, differential 0.015
- Storm Mix: RG 2.680, differential 0.006
- Storm !Q Tour 78/U: RG 2.650, differential 0.035
- Hammer Purple Pearl Urethane 78D: RG 2.632, differential 0.034
Sources: Hammer product page; Storm, "Inside The Bowling Ball"; Storm, "The Coverstock"; USBC Equipment Specifications Manual.