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T40 bits, who makes the strongest?

General Geoff

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Spent almost three hours today breaking T40 bits and running back and forth to the store and replacing them, only to break the replacements.

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Those are the broken bit ends that I was able to retrieve, along with the rotor retaining screw that I ended up having to drill out. I'd prefer not to have to go through this again, so my question is, who makes the strongest 1/2" drive T40 impact bit socket? All of these (I tried HF Pittsburgh Pro and Craftsman) sheared off within half a second, under full power on the end of an IR W7150.
 
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GTA Matt

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Did you try a handheld impact driver? Thats what they are made for. Trying to take those off with an impact wrench will break even the strongest socket, or strip out the screw.
 
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General Geoff

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You could possibly achieve success with a lower quality torx bit by just turning your impact power way down and hitting the fastener more gracefully.

Tried that, I hit it with a 1/4" impact driver rated at around 100 ft-lbs, and let it rattle for a couple of minutes with no success. I used 50/50 ATF/acetone homebrew for penetrating lubricant. I used the W7150 with lesser trigger pull to try to rattle it loose, also for a few minutes and it wouldn't budge. This particular screw just was not having it.
 

GTA Matt

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Just so we are on the same page, this is what I mean by handheld impact driver. Seriously much more effective at removing rotor screws then anything else.

hand-impact_s.jpg
 
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General Geoff

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That's too bad, hopefully you are able to find a solution. Are your attempts with bit sockets messing up the screw head at all?

If you have any torque extensions (torque sticks) you might be able to use one of those and still give the screw a good strong hit with your impact gun while also limiting the maximum force the bit sees. The torque stick would act like a spring and deaden the sharpness of the impact hit to the torx bit.

The screw head survived just fine. It did not strip out even after shearing off several bits. I very much doubt a manual impact driver would have had any effect on this screw.
 

EShield

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Funny, I get every single one out no problem with a hand impact driver, even the notorious Honda ones. But what does Matt or I know, we only work on more cars in a week than most people here will work on in a lifetime.
 

EShield

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You know how else you can ensure you never go through it again? Don't put them back in.
 
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General Geoff

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You know how else you can ensure you never go through it again? Don't put them back in.

I slathered the screws I did get out, with some anti-sieze before reinstallation. I realize that they don't really have any mechanical effect after the wheel is put back on.



Thank you, I may have to order that up. I have lots of Ko-ken stuff and have never been disappointed with them.
 
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General Geoff

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For what it's worth, I've had a ko-ken attack driver on my wishlist for a couple of years now. Maybe it's time I actually get it ordered. Next time I come across a stubborn rotor retaining screw I'll give it a whirl as well.
 
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M6erfan

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For what it's worth, I've had a ko-ken attack driver on my wishlist for a couple of years now. Maybe it's time I actually get it ordered. Next time I come across a stubborn rotor retaining screw I'll give it a whirl as well.

Well Geoff here you go...

AG112H.jpg


And guess what? It comes with a T40 impact bit...

I have it, and like it!
 
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Skin

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Impact drivers are great but you don't always have the room, or good positioning, to swing a hammer.

Stubby bit sockets are best for high torque application. More torque transfer, less twist. That said sometimes you just need the red wrench.
 

cliftonbros89

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I could use a good T40 as well. Blew apart a few Craftsman already myself. I'd like to buy a Snap On set for the shop. However I'd like a good set for my work truck too. I just don't think I want to throw down the money for 2 SO sets

Just for future reference a SK replacement bit won't work in a Craftsman socket. The SK is larger.
 

hautpot

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I am surprised nobody has mentioned a difference in impact bits and regular bits. When you use a regular screwdriver bit on your IR W7150 impact wrench you are going to break the bit nearly every time.

Impact bits are designed to have more torsion in a impact driver (or impact wrench).

Big_Bitpx350.jpg
impaktor-phillips.jpg
 

shockwave

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I have had this issue before

You need to use hand impact drivers on brake rotors especially the torx where they put thread lock in aswell

I like my Matco impact driver the best these use 5/16 bits too and I recommend the gray bits too as the snap on heavy duty is nice there coating can eat up a torx head quick
 

WhiffySpark

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Hand impact driver will work.

I personally use an air hammer and chisel, air hammer driver attachment, or just burn the f'ers out with the torch

They don't do anything if you have wheel studs. On a vw they are helpful
 

abvw

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Impact drivers are great but you don't always have the room, or good positioning, to swing a hammer.

Stubby bit sockets are best for high torque application. More torque transfer, less twist. That said sometimes you just need the red wrench.
Uh, I've never ran into a rotor set screw that I don't have room to swing a hammer. Come to think of it, I've never used my hand impact driver on anything other than brake jobs.

Hand impact drivers are a must haves for brake jobs, like e-brake piston retract tool.

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Skin

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Uh, I've never ran into a rotor set screw that I don't have room to swing a hammer. Come to think of it, I've never used my hand impact driver on anything other than brake jobs.

Hand impact drivers are a must haves for brake jobs, like e-brake piston retract tool.

Sent from my Q10 using Tapatalk

See how good of a swing you can get doing the job on a jack stand.
 

SantaAna12

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Are the SO gold ones Zephyr? And if they are, does anyone know another company that uses those bits?
 

Mastermind

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I agree with the hand impact driver. I have worked at several Honda dealers. A couple good whacks and they are turning. The Hondas use a #3 Phillips head. Found the Matco bits fit the best, had three in the drawer. Marco guy had at least one in his hand when he walked in each week. Broke a few, but would rather break a tool with a warranty and 15 or more other options in the box than have to drill out the screw. Have used this for torx screws too, cheap bits don't hold up to impact use of any kind. Back in the body shop days I had made 1/2 inch snap on bits with a 7/16 socket and the big bits. A little byutle held the bit in.

Go back to seats and get a lisle impact driver.
 

Hammer1963

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Matco sells a 5/16" shank bit that can be put in a 3/8" or 1/2" drive holder. These are the toughest bit I have found. I have tried several including Snap-on Gold and none of them have held up to impact punishment as close as the Matco combo. I keep a spare on hand and trade in the twisted or broken bit when it occurs. I have broken 2 in the past 18 months compared to weekly with other brands. I have used them on Ford truck beds, brake calipers, chassis components and structural braces.
 

Skin

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Uh, I've never ran into a rotor set screw that I don't have room to swing a hammer. Come to think of it, I've never used my hand impact driver on anything other than brake jobs.

Hand impact drivers are a must haves for brake jobs, like e-brake piston retract tool.

Sent from my Q10 using Tapatalk

Just as good as if I am using my lift. My arms are capable of full motion and a solid swing standing or crouching.

Brain fart, I was thinking the discussion was about caliper bolts.

Are the SO gold ones Zephyr? And if they are, does anyone know another company that uses those bits?

I believe Snap-On switched to their own bits a few years ago. The bits lost the usual Z in a circle and started getting stamped with the snap-on logo and date codes. Mayhew use to rebrand Zephyr or you can go for a more direct source.

http://mrotools.com/zephyr-insert-power-drive-bits.aspx
 
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nes999

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Who makes the best impact driver?

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