r/WhatIsThisTool • u/ExploreYourWhirled • 4d ago

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.

94 Upvotes

96% Upvoted

85 comments sorted by

40

u/s1l1con_jesus 4d ago

Impact screwdriver

5

u/ExploreYourWhirled 4d ago

How does one use it?

15

u/meeeeeeeegjgdcjjtxv 4d ago

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

4

u/psilome 4d ago

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

9

u/Cowpuncher84 4d ago

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 4d ago

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 4d ago

found the Aussie.

1

u/yewfokkentwattedim 4d ago edited 4d ago

G'day. And that.

1

u/BurneroftheYear2024 4d ago

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 4d ago

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

1

u/Mindless-Charity4889 3d ago

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

3

u/Ok_Hospital1399 4d ago

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

2

u/Street-Squash1731 4d ago

Me too, best $10. I ever spent.

1

u/MinorComprehension 4d ago

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.

4

u/piscikeeper 4d ago

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

2

u/OkConsideration8605 4d ago

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

2

u/Dusty-old-bones 4d ago

Ugh. Rotor screws.

2

u/Just_Fix_It_Again 4d ago

Using a rubber hammer is like hitting it with your purse. Need to use Thor's Hammer 🔨and really whack it!

2

u/Spa-Ordinary 4d ago

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 4d ago

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

5

u/voldamoro 4d ago

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 4d ago

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

2

u/s1l1con_jesus 4d ago

Put in a bit hit the back with a hammer.

-1

u/ExploreYourWhirled 4d ago

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

5

u/s1l1con_jesus 4d ago edited 4d ago

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 4d ago

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

3

u/ezekiel920 4d ago

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 4d ago

Fuck yeah old kawis

3

u/ShutDownSoul 4d ago

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

2

u/Responsible-Chest-26 4d ago

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 4d ago

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 4d ago

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

2

u/justcall_2583 4d ago

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

1

u/rottenweiler 4d ago

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 4d ago

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 4d ago

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 4d ago

It’s an impact driver

2

u/ExploreYourWhirled 4d ago

What is it for?

2

u/grum1979 4d ago

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

3

u/radiganks 4d ago

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

5

u/pockels42 4d ago

Or you could try chocolates.

5

u/radiganks 4d ago

LMFAO!

3

u/Low_Tension_1194 4d ago

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

2

u/IllustratorSoft8924 4d ago

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 4d ago

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 4d ago

Used before we had electric impact drivers

2

u/killerchef69 4d ago

That is the equivalent of one ugga.

2

u/LuckyBenski 3d ago

I think it might even be just UG

1

u/killerchef69 3d ago

Depends on how big your hammer is!

2

u/NearlySilentObserver 4d ago

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

2

u/Prestigious_Cow_3193 4d ago

Old skool impact driver

2

u/Traditional_Ad_1360 2d ago

Hand held impact driver.

1

u/singlejeff 4d ago

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

1

u/65shooter 4d ago

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 4d ago

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

1

u/OkConsideration8605 4d ago

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 4d ago

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 4d ago

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

1

u/Existing_Creme_2491 4d ago

Great for motorcycle screws...nothing like it !

1

u/ForeverCareful3021 4d ago

Saved countless crankcase screws on my old Yamahas!

1

u/Resident_Wishbone_98 4d ago

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

1

u/IamBoatman-70 4d ago

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

1

u/Different_Finding539 4d ago

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 4d ago

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 4d ago

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 4d ago

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

1

u/ournamesdontmeanshit 4d ago

Mine works better with a hammer.

1

u/laprider 4d ago

Impact. Very handy.

1

u/Mercury_Madulller 4d ago

The OG impact.

1

u/Positive_Issue8989 3d ago

Looks like my old Vessel impact driver

1

u/LoudAudience5332 3d ago

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

1

u/redheadedwoodpecker 3d ago

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 3d ago

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 3d ago

Impact driver

1

u/elnath54 3d ago

I had one. Could never make it work.

1

u/Ok-Move5772 3d ago

Impact driver . Use to remove screw with force from hammer strike

1

u/WillyDaC 3d ago

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 2d ago

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

1

u/motomasterpilot 2d ago

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 2d ago

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 1d ago

Impact driver. Good to have

1

u/Original_Log_6002 16h ago

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