Bowling ball core · Hammer
Hammer Hazmat Core
The core inside the Hammer Hazmat line
A symmetric core with early rev-up and high flare, built for medium to heavy oil. 1 of the 3 balls with this core are in stock at BowlersMart.
- Symmetric
- RG 2.470
- Diff 0.055

Specs
RG AT 15 LB
2.470
Early rev-up
2% of the reactive and urethane balls we stock have a lower RG.
DIFFERENTIAL AT 15 LB
0.055
High flare
88% of the reactive and urethane balls we stock have a lower differential.
MASS BIAS AT 15 LB
None
Symmetric core
Symmetric cores have no mass bias marker to place when drilling.
| Weight | RG | DifferentialDiff | Mass biasMB |
|---|---|---|---|
| 15 lbUsed on this page | 2.470 | 0.055 | None |
Other weights are not in our catalog for this core.
Balls with the Hammer Hazmat Core
1 of the 3 balls with the Hammer Hazmat Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.

Hammer Semtex Solid Reactive
Medium to heavy oil
Show 2 balls no longer available at BowlersMart
| Ball | Cover | First seen |
|---|---|---|
| Hammer Hazmat Pearl Bowling Ball | Hammer Semtex Solid Reactive | April 2025 |
| Hammer Hazmat Bowling Ball | Hammer Semtex Hybrid Reactive | October 2023 |
Where the Hammer Hazmat sits
Each dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.
Navy ring = a ball in your bag. Dashed ring = off this chart, or this same core.
Nearest cores, zoomed in
Navy ring = a ball in your bag. Dashed ring = off this chart, or this same core.
This core 1 Nearest cores Other cores
| Core | Brand | Shape | RG | Diff | vs this core |
|---|---|---|---|---|---|
|
|
900 Global | Symmetric | 2.470 | 0.055 | Same RG and differential |
|
|
Motiv | Symmetric | 2.470 | 0.055 | Same RG and differential |
|
|
Storm | Asymmetric | 2.470 | 0.055 | Same RG and differential |
|
|
Motiv | Asymmetric | 2.470 | 0.054 | RG 0.000 · Diff −0.001 |
|
|
Storm | Symmetric | 2.470 | 0.053 | RG 0.000 · Diff −0.002 |
|
|
Brunswick | Asymmetric | 2.473 | 0.054 | RG +0.003 · Diff −0.001 |
Matches use 15 lb RG and differential.
Drilling and tools
Turn on JavaScript to compare with your ball.Balls with the Hammer Hazmat Core1 of the 3 balls with the Hammer Hazmat Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.
Questions bowlers ask
What is the RG of the Hammer Hazmat Core?
At 15 lb the Hammer Hazmat Core has an RG of 2.470. Other weights are not in our catalog for this core.
What is the differential of the Hammer Hazmat Core?
At 15 lb the differential is 0.055. This is a symmetric core, so mass bias is not applicable.
Which bowling balls use the Hammer Hazmat Core?
Hammer Hazmat Solid Bowling Ball, Hammer Hazmat Pearl Bowling Ball, Hammer Hazmat Bowling Ball. 1 are in stock now.
How do the Hammer Hazmat Core specs change by weight?
Other weights are not in our catalog for this core.
How does the Hammer Hazmat Core compare with my ball?
Type the ball you throw into the Compare with your ball box on this page. It shows the RG and differential side by side and saves your bag for every core page.
Sources and method
Specs. Catalog 15 lb figure.
Baseline. The baseline is 265 in-stock, published reactive and urethane balls. Plastic and polyester covers, 2-piece, 3-piece and pancake cores, missing covers and missing RG or differential values are excluded.
Percentiles. Percentiles are the share of baseline balls with a strictly lower or higher value; ties are not counted.
Nearest cores. Nearest cores are ranked by distance on standardized 15 lb RG and differential, with the same symmetric or asymmetric shape preferred among near ties (distance bands of 0.1).
Mass bias. Mass bias is compared among asymmetric balls with numeric mass bias only.
Updated. Catalog and page updated 2026-10-16.


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