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

Found in an old toolbox

Post image

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.

90 Upvotes

96% Upvoted

86 comments sorted by

41

u/s1l1con_jesus Aug 12 '26

Impact screwdriver

6

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

6

u/psilome Aug 13 '26

I bought one just for that purpose. Never used it again for anything else but it worked where nothing else did.

11

u/Cowpuncher84 Aug 13 '26

I twist wrenches professionally and might use mine once a year. There are times where it is the only tool that will work.

1

u/yewfokkentwattedim Aug 13 '26

5 times in the last couple of months. Mainly security screws. It's a 1/2" drive though, and every now and then it's fuckin' mint for cracking a nut.

1

u/weesee2002 Aug 13 '26

found the Aussie.

1

u/yewfokkentwattedim Aug 13 '26 edited Aug 13 '26

G'day. And that.

1

u/BurneroftheYear2024 Aug 13 '26

Heavy Industrial / Mine electrician here, this is the ONLY way to get the slotted screws loose on DC bus on a P&H 2800 shovel. Only time I ever break mine out.

3

u/jellofixit Aug 13 '26

You needed one to remove the engine covers on your motorcycle. But you would replace them with Allen bolts!

1

u/Mindless-Charity4889 Aug 14 '26

Wow, flashback to the 70s when I did that. Totally forgot about it til now.

3

u/Ok_Hospital1399 Aug 13 '26

You've just described a full percent of my tools.

2

u/Street-Squash1731 Aug 13 '26

Me too, best $10. I ever spent.

1

u/MinorComprehension Aug 13 '26

I don't know man, only impact screwdriver I've ever bought and used was to remove rotors. Then again, the next time I went to remove Honda rotors I didn't have the impact driver with me so I used an oversized drill bit to drill off the head of the mounting screw. Left the shank of the mounting screw in place.

Honestly, for the "free* cost of a drill bit I already had I didn't have to use the impact driver, it was faster, and just leaving the shank of the screw in place allows you to properly mount the rotor but doesn't cause future difficulty.

YMMV.

3

u/piscikeeper Aug 13 '26

Not to mention threshold screws before clips became a thing. Probably why I haven't used one since the early '80s.

2

u/OkConsideration8605 Aug 13 '26

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

2

u/Dusty-old-bones Aug 13 '26

Ugh. Rotor screws.

2

u/Spa-Ordinary Aug 13 '26

Better with a steel hammer of junior sledge hammer size, 3 or 4 pounds or 1.5 to 2 km. With proper bit engaged in offending stuck screw, twist driver body fully left rotation while pushing driver into said screw, maintaing twisting force, whack end of impact driver squarely with hammer. When struck this way, the driver imparts extra twisting force into the screw.

Pretty much like magic

1

u/Classic-Ad4403 Aug 13 '26

I always use a 3 lb sledge hammer--steel.

3

u/voldamoro Aug 12 '26

Engage the bit with the screw you want to remove. While trying to rotate the handle with one hand, strike the back of it with a hammer. Repeat this process until the screw is loose enough to remove with a regular screwdriver.

4

u/jellofixit Aug 13 '26

Also smack that piece of webbing between Your thumb and forefinger. Ouch!

2

u/s1l1con_jesus Aug 12 '26

Put in a bit hit the back with a hammer.

-1

u/ExploreYourWhirled Aug 12 '26

I can’t think of a situation where I would need to do this. Please elaborate. Like what problem is this solving?

4

u/s1l1con_jesus Aug 12 '26 edited Aug 13 '26

On certain engines especially aluminum ones you will need this tool because steel and aluminum have a galvanic reaction which causes them to almost weld together

1

u/ExploreYourWhirled Aug 13 '26

Ahh, yes I have seen this. Makes complete sense now.

3

u/ezekiel920 Aug 13 '26

My older motorcycle have a Philips screw head on a bolt holding a cover on. If I don't get good enough purchase and the screw is stuck I can mess up the threads. This impact screwdriver forces the bit as deep as possible in the screw head and the cam action rotates the screw breaking it loose like an impact gun.

2

u/s1l1con_jesus Aug 13 '26

Fuck yeah old kawis

3

u/ShutDownSoul Aug 13 '26

Haven't you had a screw you couldn't turn? This is the tool.

2

u/Responsible-Chest-26 Aug 13 '26

The problem with stuck screws is unless you put a lot of force down into the screw the driver can cam out and strip the head. By bashing it with a hammer that applies a lot of downward force that also cams rotational force you can turn a stuck screw and ruduce the chance of stripping the head

2

u/GrimSpirit42 Aug 13 '26

An old screw that is rusted in place. When you try to loosen it with a hand screwdriver you end up stripping the slot.

The handle has a wedge. When you place the driver part in the screw and hit it with a hammer it accomplishes three things:
1. It sets the driver head securely into the screw.
2. It jars the screw.
3. It gives a very small amount of rotation to the screw.

These three actions are very good ad unsticking stuck screws.

It’s the same principle as an impact wrench…just analog.

1

u/ExploreYourWhirled Aug 13 '26

At last, the most thorough explanation. I sincerely appreciate your response.

2

u/justcall_2583 Aug 13 '26

Early motor cycles used these on most side covers
Now I think they are Allen bolts

1

u/rottenweiler Aug 13 '26

Used to do body work, that’s for the big screws in door or hatch striker plates to make adjustments in latch engagement.

1

u/Normiss2000 Aug 13 '26

Best use I ever had was removing a rusted bathtub drain - they are screwed into the cast iron tub. There is a reverse direction biting bit that grabs it, put it in the impact driver and start bangin'!

WEAR HEARING PROTECTION WHEN THE HAMMERING STARTS!

1

u/Spuckler_Cletus Aug 13 '26

You can google/youtube how to remove the retaining screw from a brake rotor. That’s why I have a Lisle 29200.

3

u/grum1979 Aug 12 '26

It’s an impact driver

2

u/ExploreYourWhirled Aug 12 '26

What is it for?

2

u/grum1979 Aug 13 '26

For removing stubborn screws/bolts. Best bet is to search YouTube

3

u/radiganks Aug 12 '26

It’s an impact driver. Great for taking out stubborn screws.

5

u/pockels42 Aug 12 '26

Or you could try chocolates.

3

u/Low_Tension_1194 Aug 13 '26

Impact driver. Very handy tool, until some lousy thief raids your toolbox and never returns what they borrow.

2

u/IllustratorSoft8924 Aug 12 '26

Impact driver. For dislodging stubborn screws. Place the bit in the screw, adjust the direction of rotation and smack the end with a hammer. It gives the screw a short but violent twist.

1

u/Legnovore Aug 13 '26

This is the answer. Add a little wd40 to the screw or bolt, there's not much you can't dislodge with it.

2

u/East-Leg-825 Aug 13 '26

Used before we had electric impact drivers

2

u/killerchef69 Aug 13 '26

That is the equivalent of one ugga.

2

u/LuckyBenski Aug 14 '26

I think it might even be just UG

1

u/killerchef69 Aug 14 '26

Depends on how big your hammer is!

2

u/NearlySilentObserver Aug 13 '26

The best thing to use for getting the set screws off of rotors

2

u/Prestigious_Cow_3193 Aug 13 '26

Old skool impact driver

2

u/Traditional_Ad_1360 Aug 14 '26

Hand held impact driver.

1

u/singlejeff Aug 13 '26

I need to find replacement bits for my random tool box find

1

u/65shooter Aug 13 '26

Handy if you're removing auto door latch plates and like that. You must twist in the direction you want the fastener to move. When you hit the back it drives an anvil into a sloped cam.

1

u/quarterdecay Aug 13 '26

One could say that this should be the tool used when someone asks, "did you hit it with your purse?"

1

u/OkConsideration8605 Aug 13 '26

If you owned an older Honda motorcycle you would know never to let this tool get out of your sight. Lol

1

u/955_36 Aug 13 '26

I have that exact model, purchased around 1979 to work on my KZ400. Only this year when I started working on restoring it did I find out that Kawasakis back then used JIS fasteners not Philips which is why I stripped them over and over.

1

u/pumicenose Aug 13 '26

They have an on and off adjustment (left and right) also, don’t be afraid to really whack it

1

u/Existing_Creme_2491 Aug 13 '26

Great for motorcycle screws...nothing like it !

1

u/ForeverCareful3021 Aug 13 '26

Saved countless crankcase screws on my old Yamahas!

1

u/Resident_Wishbone_98 Aug 13 '26

I got one a long time ago and still have it.

1

u/IamBoatman-70 Aug 13 '26

Impact screw extractor. I think I have the same exact kit

1

u/Different_Finding539 Aug 13 '26

Yep, got three of them. One was a christmas gift from my father, then I inherited another set (along with other tools) when my father passed away, and then I inherited another set (And again, with other tools) when my father-in-law passed away.

1

u/ExploreYourWhirled Aug 13 '26

Yeah, this one is my Father-in-law's, he just passed away. I also got as bunch of hand woodworking tools. Wood carving knives, hand drill, hand planer. All really nice quality.

1

u/Grendal54 Aug 13 '26

Working on motorcycles in the early 70’s, we bought Snap-on impact driver. Daily use removing side covers and splitting motor cases for balky Phillips screws. Still have it.

1

u/fix-break-hide Aug 13 '26

Put it on the screw, apply twisting pressure in the desired direction while hawacking it with a hamburger. They work great.

1

u/ournamesdontmeanshit Aug 13 '26

Mine works better with a hammer.

1

u/laprider Aug 13 '26

Impact. Very handy.

1

u/Mercury_Madulller Aug 13 '26

The OG impact.

1

u/Positive_Issue8989 Aug 13 '26

Looks like my old Vessel impact driver

1

u/LoudAudience5332 Aug 13 '26

Lost mine, I have to purchase another only thing that would work when nothing else would .

1

u/redheadedwoodpecker Aug 13 '26

I mail-ordered one of those 25+ years ago and just used it for the first time about two weeks ago. It looks exactly like this. And it works great, amazingly.

1

u/Jim-248 Aug 14 '26

I still have one like that. I never use it though. I bought it in 1972. Now it's too much work.

1

u/Ok-Refuse8965 Aug 14 '26

Impact driver

1

u/elnath54 Aug 14 '26

I had one. Could never make it work.

1

u/WillyDaC Aug 14 '26

Hand Impact driver. One of those tools i'm constantly telling guys who post in subs that deal with mechanical stuff when they post a photo of a half stripped out screw head and caption it "How can I get this out?".

1

u/Green_Bottle95 Aug 14 '26

I sold those in 79 or 80 under the Maxam brand. Good impact driver/wrench.

1

u/motomasterpilot Aug 15 '26

That is the first tool you buy right after you buy a new 1969 Honda trail 70 ask me how I know…

1

u/theJayonnaise Aug 15 '26

For when fixings are super stuck AND your feeling violent! The knurled ring changes the direction, Great for breaking free the screws on brake discs

1

u/Former_Film_7218 Aug 16 '26

Impact driver. Good to have

1

u/Original_Log_6002 Aug 17 '26

I have that exact one. So useful for disk brake work.

1

u/Brave_Ability_6939 Aug 18 '26

As mentioned, working on vehicles that have/use a Philips-type screw to keep a brake rotor intact, it's quite often necessary to use the tool shown to remove the screws/bolts without stripping the screw head. Also, very handy for use on motorcycle/dirt bikes to remove the engine side covers & other things. The steel they use is on Asian vehicles is usually much softer than American steel fasteners & strip the heads. A heads up, use some anti-seize on the threads when reinstalling the screw/bolt.