Arm Assassin Thumb Blaster

Name: Arm Assassin Thumb Blaster
Brand: Arm Assassin
Rating: 4.86 (7 reviews)

The Thumb Blaster is a single-purpose grip trainer built to isolate thumb pressure during pinch-grip work. Unlike sharp-edged pinch tools such as Euro pinch blocks or “the Flask,” its handle is rounded, which — per the maker’s own explanation — avoids tearing the thumb webbing during heavy pinch sets. Flipped around, the same handle also works a half-crimp finger grip, and it can be loaded via loading pin or cable, making it a compact way to train thick-bar-style pinch strength without a full plate stack.

It ships in three interchangeable thicknesses — 1 5/8”, 2”, and 2 3/8” — so lifters can match the handle to hand size or use the sizes for progressive overload. Within the grip-sport and armwrestling community (GripBoard forum threads), the tool is actively used for serious pinch-strength training, including reported personal records on the 1 5/8” size, with no negative feedback surfacing in available discussion. Independent coverage remains thin, however — there’s no third-party editorial teardown, and even Arm Assassin’s own founder notes in a 2024 shop-tour video that he hasn’t personally used the tool himself.

Loading	loading pin or cable
Use cases	thumb/pinch grip training, half-crimp finger grip, thick-bar-style pinch
Related product	Double Thumb Blaster (dual-sided version, $60)
Sizes available	1 1/4", 1 5/8", 2", 2 3/8"

How it compares

	Arm Assassin Thumb Blaster	Napalm One Hand Nightmare	IronMind Hub	Pinch Coin
GymRadar rating	4.86/5	4.86/5	4.85/5	4.85/5
Price	$35.00		$36.95
Loading	loading pin or cable
Use cases	thumb/pinch grip training, half-crimp finger grip, thick-bar-style pinch
Related product	Double Thumb Blaster (dual-sided version, $60)
Sizes available	1 1/4", 1 5/8", 2", 2 3/8"

4.9/5 · 7 GymRadar reviews

Reviews by source

Expert

4.86/5

7 reviews

A single-purpose grip tool for isolating the thumb during pinch training — Arm Assassin’s own founder describes its edge over rivals like the Euro pinch block and “the Flask” plainly: a rounded handle profile instead of a sharp edge, so pinch and thick-bar work doesn’t tear the thumb webbing the way sharp-edged plates can. Functionality is the standout dimension — one handle covers thumb-pinch, half-crimp finger, and thick-bar-style movements, and it loads via pin or cable. Build quality looks solid (welded steel, per the maker’s own description of the labor involved) but has no independent teardown to confirm it. The weakest dimension is durability — there’s no long-term wear data from independent sources, only grip-sport forum anecdotes of the tool (and close DIY replicas) holding up under serious pinch-strength PRs. Versatility is real but narrow: three interchangeable thicknesses (1 5/8”, 2”, 2 3/8”) suit different hand sizes and progressive overload, but it remains a single-exercise accessory rather than a broader training tool.

+Functionality: rounded handle profile avoids the thumb-webbing tears sharp-edged pinch tools (Euro pinch block, "the Flask") can cause (Arm Assassin Strength Shop tour, HomeGymCon 2024)
+Functionality: one implement covers three movements — thumb-pinch focus, half-crimp finger grip, and thick-bar-style pinch (Arm Assassin Strength Shop tour, HomeGymCon 2024)
+Versatility: available in three thicknesses (1 5/8", 2", 2 3/8") so lifters can match hand size or progressively overload by swapping handle diameter (manufacturer product page)
+Value: $35 list price for a single-purpose but well-regarded grip-sport training tool (manufacturer product page)
+Functionality: loads via pin or cable, and grip-sport competitors have used it as a fair adjustable-handle alternative to the much slower Euro pinch block format in contest settings (Arm Assassin Strength Shop tour, HomeGymCon 2024)

−Durability: no independent long-term wear data — only forum anecdotes of the tool or close DIY replicas holding up under serious use (GripBoard community threads)
−Build quality: no independent editorial review has evaluated fit/finish or weld quality; only the maker's own description exists (Arm Assassin Strength Shop tour, HomeGymCon 2024)
−Versatility: a single-exercise accessory (pinch/finger/thick-bar grip work) rather than a general training tool (manufacturer product page)
−Functionality: even the shop's own founder notes he has "never used these" personally, so first-hand functional feedback is thin (Arm Assassin Strength Shop tour, HomeGymCon 2024)

$35.00

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