Hammer Black Widow specs

The Hammer Black Widow is a polyester (plastic) ball with the Gas Mask 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.

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Coverstock	Polyester
Cover type	Polyester
Core (weight block)	Gas Mask
Core type	Not stated
RG	2.480
Differential	0.058
Mass bias / intermediate diff.	0.013
Factory finish	500, 1000, 2000 Siaair / Factory Polish
Maker's category	Spare Balls
Colors	White Diamond, Viz-A-Ball
Weights	16-10 Pounds
Release date (maker)	September 17, 2026

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.

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What the numbers mean

Polyester cover. Polyester (plastic) is the cover used for spare balls and house balls: it grips the lane least, so the ball goes nearly straight. See our plastic spare ball review.

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:

Radical The Spy: RG 2.513, differential 0.053
Motiv Aspire: RG 2.750, differential 0.028
Storm Ice Storm Ocean Blue-White: RG 2.680, differential 0.006
Storm Ice Storm Teal-Silver-Graphite: RG 2.680, differential 0.006

Sources: Hammer product page; Storm, "Inside The Bowling Ball"; Storm, "The Coverstock"; USBC Equipment Specifications Manual.