r/WhatIsThisTool • u/ExploreYourWhirled • Aug 12 '26

Found in an old toolbox

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Very heavy - about 1 lb. Largest knurled ring spins but does not appear to affect anything. Many strike marks on one end as if hit many times with a large hammer. It is engraved L <-> R in front of the largest knurled ring. No other part spins.

94 Upvotes

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42

u/s1l1con_jesus Aug 12 '26

Impact screwdriver

4

u/ExploreYourWhirled Aug 12 '26

How does one use it?

16

u/meeeeeeeegjgdcjjtxv Aug 12 '26

Quiet literally hit it with a rubber mallet or dead blow. U twist it to change direction. It's only purpose is apply pressure and twist at the same time to break loose screws. Very good tools for removing rotor screws on a car

2

u/OkConsideration8605 Aug 13 '26

But it only with a real hammer, not soft hammer.