Bowling ball core · Hammer

Hammer Gas Mask Core

The core inside the Hammer Black Widow line

An asymmetric core with mid-lane rev-up and very high flare, built for medium to heavy oil. 11 of the 67 balls with this core are in stock at BowlersMart.

  • Asymmetric
  • RG 2.500
  • Diff 0.058
  • MB 0.016
Hammer Gas Mask asymmetric core shape inside the ball

Specs

RG AT 15 LB

2.500

Mid-lane rev-up

Revs soonerRevs later

42% of the reactive and urethane balls we stock have a lower RG.

DIFFERENTIAL AT 15 LB

0.058

Very high flare

Less flareMore flare

96% of the reactive and urethane balls we stock have a lower differential.

MASS BIAS AT 15 LB

0.016

Mild asymmetry

MilderStronger

33% of the asymmetric reactive and urethane balls we stock have a lower mass bias.

RG How soon the ball revs up.Differential How much the ball can flare.Mass bias How asymmetric the core is.
Hammer Gas Mask Core specs by ball weight
Weight RG DifferentialDiff Mass biasMB
16 lb 2.510 0.048 0.015
15 lbUsed on this page 2.500 0.058 0.016
14 lb 2.500 0.056 0.016
13 lb 2.589 0.043 0.011
12 lb 2.612 0.043 0.011

Source: Hammer published specs, as shown on BowlersMart’s original Gas Mask core page (2022). RG and differential change with ball weight; use the row for the weight you throw. The highlighted 15 lb row is the one used on this page.

2 balls on this core list different numbers
  • Hammer Black Widow Spare+ Bowling Ball: RG 2.480, diff 0.058, mass bias 0.013 at 15 lb
  • Hammer Black Widow Viz-a-Ball Bowling Ball: RG 2.480, diff 0.058, mass bias 0.013 at 15 lb

Balls with the Hammer Gas Mask Core

11 of the 67 balls with the Hammer Gas Mask Core are in stock at BowlersMart. Same core, different covers: pick the cover for the lanes you bowl on.

Solid covers

Solid covers grip the lane soonest and suit heavier oil.

Hammer Black Widow 3.0 Dynasty Bowling Ball

Hammer Black Widow 3.0 Dynasty

Hammer HK22 Cohesion Solid Reactive

Medium to heavy oil

Sale price $169.95 Regular price $249.95In stock
Hammer Black Widow 3.0 Bowling Ball

Hammer Black Widow 3.0

Hammer HK22 Aggression Solid

Medium to heavy oil

Sale price $144.95 Regular price $249.95In stock
Hammer Black Widow 2.0 Bowling Ball

Hammer Black Widow 2.0

Hammer Aggression Solid Reactive

Medium to heavy oil

Sale price $159.95 Regular price $249.95In stock
Hammer Black Widow Toxin Solid Overseas Bowling Ball

Hammer Black Widow Toxin Solid Overseas

Hammer Hyper Aggression Solid Reactive

Medium to heavy oil

Sale price $199.95 Regular price $329.95In stock

Hybrid covers

Hybrid covers mix solid grip with pearl length.

Hammer Black Widow 2.0 Hybrid Bowling Ball

Hammer Black Widow 2.0 Hybrid

Hammer Aggression Hybrid Reactive

Medium to heavy oil

Sale price $144.95 Regular price $249.95In stock
Hammer Black Widow Toxin Hybrid Overseas Bowling Ball

Hammer Black Widow Toxin Hybrid Overseas

Hammer Aggression Plus Hybrid Reactive

Medium to heavy oil

Sale price $199.95 Regular price $329.95In stock

Pearl covers

Pearl covers go longer and turn harder at the end, best on medium oil.

Hammer Black Widow Mania Bowling Ball

Hammer Black Widow Mania

Hammer HK22 Cohesion Pearl

Medium to heavy oil

Sale price $144.95 Regular price $249.95In stock
Hammer Black Widow Ghost Pearl Bowling Ball

Hammer Black Widow Ghost Pearl

Hammer Aggression Pearl Reactive

Medium to heavy oil

Sale price $159.95 Regular price $249.95In stock
Hammer Black Widow Toxin Pearl Overseas Bowling Ball

Hammer Black Widow Toxin Pearl Overseas

Hammer Hyper Aggression Plus Pearl Reactive

Medium to heavy oil

Sale price $199.95 Regular price $329.95In stock

Spare ball versions

Plastic spare balls roll straight; the core barely matters here.

Hammer Black Widow Spare+ Bowling Ball

Hammer Black Widow Spare+

Polyester (Plastic)

Light oil, dry

Sale price $149.95 Regular price $229.95In stock
Hammer Black Widow Viz-a-Ball Bowling Ball

Hammer Black Widow Viz-a-Ball

Plastic

Dry

Sale price $129.95 Regular price $229.95In stock
Show 56 balls no longer available at BowlersMart
More bowling balls with the Hammer Gas Mask Core
Ball Cover First seen
Hammer Black Widow Night Breaker Overseas Bowling Ball Hammer Semtex Pearl Reactive January 2023
Hammer Black Widow Assassin Bowling Ball Hammer NBT Solid Reactive January 2014
Hammer Black Widow Legend Bowling Ball Hammer NBT Hybrid Reactive June 2014
Hammer Black Widow R Overseas Bowling Ball Hammer Lethal Bite Solid Reactive August 2014
Hammer Black Widow M Overseas Bowling Ball Hammer Fang Hybrid Reactive August 2014
Hammer Black Widow Omega Overseas Bowling Ball Hammer Fang Solid Reactive August 2014
Hammer Black Widow Insanity Overseas Bowling Ball Hammer Primer Reactor Max Reactive September 2014
Hammer Black Widow Limited Bowling Ball Hammer Semtex Pearl Reactive October 2015
Hammer Black Widow Dark Legend Bowling Ball Hammer Semtex Hybrid Reactive January 2016
Hammer Widow Spare Blue Orange Smoke Bowling Ball Plastic September 2016
Hammer Gold Taboo CFI Overseas Bowling Ball Hammer Aggression Pearl CFI Reactive October 2016
Hammer Black Widow Gold Bowling Ball Hammer Semtex Pearl Reactive November 2016
Hammer Black Widow Urethane Bowling Ball Hammer Hammer Black Solid Urethane November 2017
Hammer Black Widow Legendary Bowling Ball Hammer GTR Grand Theft Hybrid Reactive June 2018
Hammer Scorpion Pure Overseas Bowling Ball Hammer Pure Adrenaline Reactive July 2018
Hammer Scorpion Swing Overseas Bowling Ball Hammer Rage Reactive July 2018
Hammer Black Widow Black Gold Bowling Ball Hammer Aggression Hybrid Reactive July 2018
Hammer Black Widow Excess Overseas Bowling Ball Hammer Semtex Hybrid Reactive November 2018
Hammer Amazing Rip’d Bowling Ball Hammer Aggression Pearl CFI Reactive November 2018
Hammer Scorpion Solid Overseas Bowling Ball Hammer Semtex Solid Reactive November 2018
Hammer Black Widow Pink Bowling Ball Hammer Aggression Pearl CFI Reactive March 2019
Hammer Platinum Black Widow Copper Bowling Ball Pearl Reactive September 2019
Hammer Platinum Black Widow Blood Orange Overseas Bowling Ball Hammer Violent Aggression CFI Reactive September 2019
Hammer Black Widow Hybrid Bowling Ball Hammer Aggression Hybrid CFI Reactive September 2019
Hammer Black Widow Platinum White Bowling Ball Hammer Aggression Bite Pearl Reactive November 2019
Hammer Black Widow Death Blow Bowling Ball Hammer Aggression Solid CFI Reactive November 2019
Hammer Black Widow Platinum Silver Bowling Ball Reactive November 2019
Hammer Black Widow Platinum Blue Sparkle Bowling Ball Hammer Aggression Pearl CFI Reactive December 2019
Hammer Black Widow Purple Pearl Urethane Overseas Bowling Ball Hammer Pearl Urethane June 2023
Hammer Black Widow Orange Sparkle Platinum Bowling Ball Hammer Aggression NE Pearl Reactive December 2019
Hammer Black Widow Purple Overseas Bowling Ball Hammer Platinum P Reactive April 2021
Hammer Black Widow Red Overseas Bowling Ball Hammer Platinum R Reactive June 2021
Hammer Black Widow Black Reactive Overseas Bowling Ball Hammer Platinum B Reactive January 2021
Hammer Black Widow 2.0 Alpha Overseas Bowling Ball Hammer Aggression NE Hybrid Reactive January 2021
Hammer Black Widow Hybrid Overseas Bowling Ball Hammer Aggression NE Hybrid Reactive August 2024
Hammer Black Widow Real Monster Overseas Bowling Ball Hammer Aggression NE Pearl Reactive April 2021
Hammer Black Widow Domination Overseas Bowling Ball Hammer Envy Solid CFI Solid Reactive June 2023
Hammer Black Widow Urethane Pink Pearl Bowling Ball Hammer Pearl Urethane February 2022
Hammer Black Widow Savage Overseas Bowling Ball Hammer Envy CFI Pearl Reactive June 2023
Hammer Black Widow Black Solid Urethane Overseas Bowling Ball Hammer Performance Urethane Solid June 2024
Hammer Taboo GRB Overseas Bowling Ball Hammer Envy Solid CFI Solid Reactive April 2022
Hammer Black Widow Red Pearl Urethane Overseas Bowling Ball Hammer Hammer Red Pearl Urethane June 2023
Hammer Black Widow Real Monster Solid Overseas Bowling Ball Hammer Neoflex 25 Solid Reactive June 2024
Hammer Taboo Hybrid Overseas Bowling Ball Hammer Platinum Hybrid Reactive August 2022
Hammer Black Widow Darkness Overseas Bowling Ball Hammer Aggression NE Pearl Reactive January 2023
Hammer Black Widow Red Solid Urethane Overseas Bowling Ball Hammer RS Urethane Solid June 2024
Hammer Black Widow XR Gold Pearl Overseas Bowling Ball Hammer Envy CFI Pearl Reactive June 2024
Hammer Black Widow Caramel Urethane BGD Overseas Bowling Ball Hammer B.P Urethane June 2023
Hammer Black Widow Dark Night Overseas Bowling Ball Hammer Aggression Pearl CFI Reactive August 2023
Hammer Black Widow Legend Pearl Overseas Bowling Ball Hammer Envy CFI Pearl Reactive August 2022
Hammer Black Widow 2.0 Pearl Overseas Bowling Ball Hammer Aggression Pearl Reactive April 2024
Hammer Black Widow 3.0 Platinum Overseas Bowling Ball Hammer HK22 Cohesion Pearl August 2023
Hammer Black Widow Purple Solid Urethane Overseas Bowling Ball Hammer Hammer Purple Solid Urethane August 2023
Hammer Black Widow Blue Pearl Urethane Overseas Bowling Ball Hammer Pearl Urethane August 2023
Hammer Black Widow Nightmare Overseas Bowling Ball Hammer HK22 Cohesion Pearl April 2025
Hammer Black Widow 3.0 Poison Overseas Bowling Ball Hammer HK22 Aggression Solid April 2025

Shop the 11 available balls with this core

Where the Hammer Gas Mask sits

Each dot is a core in balls we stock. Cores close together roll alike; the cover and layout decide the rest.

DV8 Larceny Core, RG 2.471, diff 0.028DV8 Renegade Core, RG 2.499, diff 0.040Track I-Core Gen4, RG 2.480, diff 0.053Brunswick Vintage Light Bulb Low RG Core, RG 2.560, diff 0.032Brunswick Dual Centric Core, RG 2.500, diff 0.047Hammer Stacked LED Core, RG 2.545, diff 0.047Hammer Vindicator Core, RG 2.474, diff 0.053Radical Vexed Variant Asymmetric Core, RG 2.490, diff 0.045Radical Modified Intel Symmetric Core, RG 2.483, diff 0.032Motiv Affliction V2 Core, RG 2.480, diff 0.055900 Global Conduit A.I. Core, RG 2.590, diff 0.050Hammer Obsession Tour, RG 2.460, diff 0.034Hammer Super Offset Core, RG 2.524, diff 0.053Ebonite Turbo Core, RG 2.510, diff 0.040Ebonite Centrex Symmetrical Mass Bias, RG 2.460, diff 0.056Motiv Excel Core, RG 2.550, diff 0.030Motiv Detonator Core, RG 2.470, diff 0.055Storm Solarion AI Core, RG 2.480, diff 0.054SWAG Insanity Symmetric Core, RG 2.520, diff 0.034SWAG Fusion Symmetric Core, RG 2.540, diff 0.036SWAG Watcher Symmetric Core, RG 2.510, diff 0.048SWAG Dragon Asymmetric Core, RG 2.480, diff 0.054SWAG Executioner Asymmetric Core, RG 2.500, diff 0.051Motiv Predator V2 Core, RG 2.470, diff 0.054Storm C3 Centripetal Control Core, RG 2.490, diff 0.029Hammer Vibe Core, RG 2.510, diff 0.042Hammer Aftermath Core, RG 2.520, diff 0.052Brunswick Alert Core, RG 2.470, diff 0.037Brunswick Rampart Core, RG 2.500, diff 0.051DV8 Collision Core, RG 2.462, diff 0.052Track MC2 Asym Core, RG 2.470, diff 0.046Radical Evil Eye Symmetric Core, RG 2.490, diff 0.046Ebonite Iron Fist V2 Core, RG 2.470, diff 0.053Radical No Doubt Symmetric Core, RG 2.480, diff 0.051Storm Surge Core, RG 2.580, diff 0.024Roto Grip Hyped UP Core, RG 2.500, diff 0.042Roto Grip Morph-Wing Core, RG 2.510, diff 0.051Brunswick Fury Core, RG 2.524, diff 0.038Motiv Sigma Core, RG 2.470, diff 0.047Roto Grip Hustle Core, RG 2.530, diff 0.030900 Global Blast AI Core, RG 2.470, diff 0.055900 Global Strobe AI Core, RG 2.510, diff 0.052Radical Guru Core, RG 2.500, diff 0.044Track I-CORE 3.0, RG 2.480, diff 0.056DV8 Unholy Core, RG 2.500, diff 0.051Brunswick Infinity Core, RG 2.520, diff 0.051Storm Catalyst Core, RG 2.500, diff 0.052Hammer Gauntlet Core, RG 2.501, diff 0.050Hammer Raw Hammer Core, RG 2.537, diff 0.038Storm Atmos A.I. Core, RG 2.530, diff 0.042Storm Booster Core, RG 2.540, diff 0.046Track Shuttle Core, RG 2.490, diff 0.038Brunswick Light Bulb Core, RG 2.524, diff 0.030Radical Sneak Attack Core, RG 2.540, diff 0.036Motiv Gear Core, RG 2.480, diff 0.034Hammer Huntsman Core, RG 2.470, diff 0.050Hammer Super LED Core, RG 2.630, diff 0.034Ebonite Enhanced V2 Core, RG 2.480, diff 0.048DV8 Dualistic Core, RG 2.490, diff 0.045Radical Vexed Asymmetric Core, RG 2.490, diff 0.036Motiv Quadfire Core, RG 2.550, diff 0.043Track Stealth Core, RG 2.480, diff 0.056Brunswick Tiered Hexagon Core, RG 2.540, diff 0.045Columbia 300 Piranha Core, RG 2.550, diff 0.043Storm Torsion AI Core, RG 2.470, diff 0.050Storm Element Max AI Core, RG 2.470, diff 0.055Storm Radius Core, RG 2.610, diff 0.020Roto Grip Rondure Tour X Core, RG 2.480, diff 0.034SWAG Unreal Core, RG 2.510, diff 0.047SWAG Craze Core, RG 2.520, diff 0.030SWAG Serpent Asymmetric Core, RG 2.510, diff 0.048Radical Torpedo Asymmetric Core, RG 2.480, diff 0.054Motiv Overload, RG 2.480, diff 0.050DV8 Duality Core, RG 2.480, diff 0.036Hammer Spheroid Core, RG 2.480, diff 0.048Radical Outer Limits Asymmetric, RG 2.490, diff 0.051Motiv Apex Predator Core, RG 2.520, diff 0.055Brunswick Danger Zone Core, RG 2.501, diff 0.048Storm RAD-TQ Core, RG 2.560, diff 0.051Storm Velocity Core, RG 2.480, diff 0.051Hammer LED Resin Bowling Ball Core, RG 2.586, diff 0.027Epic Spark Core, RG 2.540, diff 0.049Motiv Hadron Dual Density Core, RG 2.500, diff 0.045Track Criterion ID Core, RG 2.490, diff 0.047Brunswick Zone Asymmetric Core, RG 2.470, diff 0.048Ebonite Entity Core, RG 2.510, diff 0.052Roto Grip Rocker AI Core, RG 2.480, diff 0.050Motiv Flux Core, RG 2.570, diff 0.015DV8 Mantra Core, RG 2.490, diff 0.047Hammer Gas Mask Low Diff Core, RG 2.500, diff 0.034Roto Grip RST Core + AI, RG 2.520, diff 0.055Motiv Impulse V2 Core, RG 2.550, diff 0.050SWAG APX V1 Core, RG 2.500, diff 0.042SWAG Fusion Core, RG 2.540, diff 0.036SWAG Judge Core, RG 2.490, diff 0.052900 Global Magna AI Core, RG 2.490, diff 0.044Roto Grip Rondure Core, RG 2.490, diff 0.052Columbia 300 Pulse PowerCOR, RG 2.460, diff 0.045Storm Element Tour A.I. Core, RG 2.470, diff 0.035KR Strikeforce KR Launch Core, RG 2.530, diff 0.047900 Global Ellipse Asymmetric A.I. Core, RG 2.480, diff 0.050Motiv Halogen Core, RG 2.550, diff 0.037Storm C3 + AI Core, RG 2.480, diff 0.031Motiv Gear APG, RG 2.470, diff 0.036Radical Snapshot Symmetric Core, RG 2.520, diff 0.050Hammer High Rev Offset Core, RG 2.489, diff 0.053Hammer Huntsman Tour Core, RG 2.472, diff 0.036Hammer LED Core, RG 2.650, diff 0.015Storm Inverted Fe2 Core, RG 2.570, diff 0.046Storm Capacitor Core, RG 2.570, diff 0.022Storm Velocity A.I. Core, RG 2.470, diff 0.053Storm Atomic Core, RG 2.480, diff 0.053Storm RAD-X Asymmetric, RG 2.480, diff 0.054Hammer FAB Asymmetric, RG 2.550, diff 0.051Columbia 300 Shifter Core, RG 2.470, diff 0.050Radical Modified Intel Symmetric, RG 2.480, diff 0.032Columbia 300 Columbia Ricochet Core, RG 2.480, diff 0.054Roto Grip Defense AI Core, RG 2.490, diff 0.053Storm Supercoil Core, RG 2.470, diff 0.053Storm Centripetal HD A.I. Core, RG 2.460, diff 0.056Hammer Modified Infamous Core, RG 2.560, diff 0.049Brunswick Ethos Core, RG 2.480, diff 0.053Hammer Hazmat Core, RG 2.470, diff 0.055Track Criterion MD Core, RG 2.500, diff 0.052Storm Ignition Core, RG 2.490, diff 0.052Roto Grip Momentous A.I. Core, RG 2.480, diff 0.049Brunswick Portal X Core, RG 2.470, diff 0.054Radical Katana Core, RG 2.500, diff 0.050900 Global Meditate LD Symmetric Core, RG 2.560, diff 0.027Roto Grip Rondure MaxD Core (pictured: Roto Grip Wicked Gremlin Bowling Ball)1Roto Grip GEM A.I. Core (pictured: Roto Grip Perfect Gem Bowling Ball)2Ebonite Big Time Core (pictured: Ebonite Go Time Bowling Ball)3Storm ID AI Core (pictured: Storm Identity Bowling Ball)4Columbia 300 Movement Core (pictured: Columbia 300 Command Solid Bowling Ball)5Ebonite Emerge Core (pictured: Ebonite Emerge Hybrid Bowling Ball)6Hammer Gas Mask Core (pictured: Hammer Black Widow 2.0 Bowling Ball)EARLY REV-UPMID-LANELATER REV-UPHIGH FLAREMEDIUMLOW FLARE2.442.482.522.562.602.642.680.0100.0200.0300.0400.0500.060RG at 15 lbDifferential at 15 lb← Revs up soonerRevs up later →More flare ↑Less flare ↓

Nearest cores, zoomed in

Hover or tap a dot for that core’s numbers. Click a dot to open its page. Drag to move around when zoomed in. The same RG and differential do not guarantee the same ball motion.

Same family: Hammer Gas Mask Low Diff Core

This core 1 Nearest cores Other cores

Nearest cores to the Hammer Gas Mask Core
Core Brand Shape RG Diff vs this core
Roto Grip Wicked Gremlin Bowling Ball1Roto Grip Rondure MaxD CorePictured: Roto Grip Wicked Gremlin
 Roto Grip Asymmetric 2.500 0.058 Same RG and differential
Roto Grip Perfect Gem Bowling Ball2Roto Grip GEM A.I. CorePictured: Roto Grip Perfect Gem
 Roto Grip Asymmetric 2.490 0.057 RG −0.010 · Diff −0.001
Ebonite Go Time Bowling Ball3Ebonite Big Time CorePictured: Ebonite Go Time
 Ebonite Symmetric 2.500 0.054 RG 0.000 · Diff −0.004
Storm Identity Bowling Ball4Storm ID AI CorePictured: Storm Identity
 Storm Asymmetric 2.510 0.055 RG +0.010 · Diff −0.003
Columbia 300 Command Solid Bowling Ball5Columbia 300 Movement CorePictured: Columbia 300 Command Solid
 Columbia 300 Asymmetric 2.510 0.053 RG +0.010 · Diff −0.005
Ebonite Emerge Hybrid Bowling Ball6Ebonite Emerge CorePictured: Ebonite Emerge Hybrid
 Ebonite Asymmetric 2.510 0.053 RG +0.010 · Diff −0.005

Matches use 15 lb RG and differential.

Drilling and tools

Drilling layoutsLayout guides for symmetric and asymmetric ballsDual angle converterTurn a pin to PAP layout into a dual angle layout

The Black Widow features the Gas Mask core shape the bowling world knows and loves. This core is combined with a Carbon Fiber outer core for durability and power.  

From Hammer’s description

Questions bowlers ask

What is the RG of the Hammer Gas Mask Core?

At 15 lb the Hammer Gas Mask Core has an RG of 2.500. It ranges from 2.500 to 2.612 across the listed weights.

What is the 14 lb RG of the Hammer Gas Mask Core?

At 14 lb the RG is 2.500.

What is the differential of the Hammer Gas Mask Core?

At 15 lb the differential is 0.058. The mass bias is 0.016.

Which bowling balls use the Hammer Gas Mask Core?

Hammer Black Widow 3.0 Dynasty Bowling Ball, Hammer Black Widow Mania Bowling Ball, Hammer Black Widow 3.0 Bowling Ball, Hammer Black Widow 2.0 Hybrid Bowling Ball, Hammer Black Widow 2.0 Bowling Ball. 11 are in stock now.

How do the Hammer Gas Mask Core specs change by weight?

At 16 lb: RG 2.510, differential 0.048, mass bias 0.015. At 12 lb: RG 2.612, differential 0.043, mass bias 0.011.

How does the Hammer Gas Mask 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. Hammer published specs, as shown on BowlersMart’s original Gas Mask core page (2022), as published by the manufacturer.

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.

Next lesson

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