This video documents an experiment by the Torque Test Channel to increase the torque output of a Milwaukee M18 1/2" impact wrench by modifying its internal hammer mechanism. The objective was to increase the hammer's mass, thereby increasing the force of each impact according to the F=ma principle. Because pure tungsten is too brittle to serve as a hammer, the project involved having a specialized machine shop mill nearly 40 holes into the tool's original hardened steel hammer. These holes were then filled with slugs of raw tungsten (density: 19.3 g/cm³), secured with a retaining compound. The modification successfully added approximately half a pound of weight to the hammer assembly. Testing demonstrated that while the tool's operational speed (RPM/IPM) decreased, the increased mass resulted in harder individual impacts. This culminated in a new channel record for peak torque (1,122 ft-lbs, presumably), but only when paired with high-output batteries capable of spinning the heavier mass. As far as I can tell, the result was entirely predictable: the modification was not durable, and the tungsten slugs were violently ejected by the operational vibrations, destroying the assembly. The project is framed as an absurdly expensive and impractical but successful engineering exercise.
Modifying an Impact Wrench with Tungsten for Maximum Torque
0:00:05 The Premise: The goal is to increase an impact wrench's power by increasing the mass of its hammer. Raw tungsten is chosen for its extreme density (19.3 g/cm³), which is roughly 2.5 times that of the hammer's original steel (~7.8 g/cm³).
02:00 The Problem with Tungsten: A hammer made entirely of tungsten would be too brittle and would likely shatter under impact. The plan, therefore, is to embed tungsten slugs into the existing, ductile steel hammer.
04:31 The Machining Challenge: The stock hammer is hardened to over 61 HRC, making it impossible to drill with conventional tools. A specialist machine shop, Hill Precision Tool, is contracted to mill the necessary holes using carbide tooling.
05:46 Cosmetic Side Quest: While the hammer is being machined, the tool's red plastic housing is dyed black using Rit dye to give it a more "tungsten-like" appearance. I don't care about this, but it was done.
09:48 The Resulting Mass: The tungsten slugs and retaining compound add about half a pound of weight to the hammer assembly, increasing its total mass by over 20%. The mass of the hammer component itself is increased by a much higher percentage.
10:36 Performance Testing & Power Requirements: The modified tool produces significantly more torque than the stock version, but only when supplied with high-current batteries (Milwaukee's Forge series). Standard batteries struggle to spin up the heavier mass, resulting in mediocre performance and significant heat generation.
14:04 New Torque Record: After a cool-down period, the modified tool paired with a 12A Forge battery achieves a peak torque of 1,122 ft-lbs, a new channel record for a 1/2" impact wrench. This confirms the hypothesis that greater mass, with sufficient power, yields harder hits.
15:34 Catastrophic Failure: The experiment ends in predictable, rapid self-destruction. The immense vibrations cause the retaining compound to fail, and the tungsten slugs are violently ejected from the hammer.
16:56 Final Verdict: The project is deemed "absolutely not worth it" due to its extreme cost, complexity, and lack of durability. It exists only as a successful, if pointless, proof-of-concept.
Error: value error Invalid operation: The response.text quick accessor requires the response to contain a valid Part, but none were returned. The candidate's finish_reason is 1.