Kind of bummed using the craftsman thread restorers

[ajchien]

Sorry, my camera isn't taking photos well, so I guess I'll try to describe as best as possible.

Should have been a simple morning, rear brake pads on my wife's 03 Honda Element with 210k miles.

Everything is fine until I go and put the wheels back on, one lug nut makes the impact hammer a lot, take it off and I notice the stud has a single thread that is bent over a bit.

So I get my craftsman (Kastar/Lang) 12x1.5 thread restorer tap and die out, all done with oil. The tap went through the lugut a few times and is now smooth. But the restorer tap itself now has one thread that is sheared off. The die went into the stud and does its thing. After everything spins smoothly with the die i notice the stud thread is bent over into the valley of the thread rather than straightened out i try to spin on the lug nut anyway - no go. Do the same thing again for no apparent reason, and get no different results.

Well thankfully I have a craftsman 12x1.5 die. The real cutting die type. I spin that onto the stud back and forth twice and it removed the bent thread out of the valley of the lug stud. Everything fine now.

Just kind of annoyed a buggered thread was fixed easier with a cutting tap/die set rather than with a restorer set.

 

[pauls_workshop]

It is hard without photos, but might have been just too much for the restorer tap to handle alone if that badly messed up. The true tap/die will always work, but you will lose material in the process, which might be ok or might not be ok, all depending. Losing one thread of a bolted joint may not matter if there are some extra engaged threads available in the design of the bolted joint. Generally, you'll not know this, but a rule of thumb is 1xdia of bolt = minimum length of thread engagement. Less than that engagement can result in loosening bolted joints over time. I design myself for at least 1.5xdia of bolt = min thread engagement length along the bolt to be safe. - Paul, ME on the side

 

[SuburbanRuss]

You wheel studs may be hardened steel beyond that of the restorer. it *****, however it may just not have been the right tool. whenever i screw up the threads on wheel studs i have been taught to hand file it. Glad the cutting die worked.

 

[OutsideMachinist]

The thread restorer is just for a quick/easy fix. I always use a tap and ''real'' die.

 

[tjmonsen5]

I find thread files work better on studs to fix threads than the restor die.

 

[gtg082y]

+1 for thread files... I always try the files first, even if it is only to get a small improvement before switching to a die (either restoring or cutting).

 

[Mastermind]

Thread file for a single thread fold. Lug studs are cheap to replace and generally easy. Esp. If you just had the brakes apart. And I always replace a lug nut after a crossthread.

 

[trxrx7]

i agree with everyone above, thread files work way better.

 

[sonvolt]

The thread restorer is just for a quick/easy fix. I always use a tap and ''real'' die.

This ^^^^

 

[warmpancakes]

The thread restorer is just for a quick/easy fix. I always use a tap and ''real'' die.

not the correct tool to repair threads Taps and Dies are for cutting new threads, using a tap or die removes metal and will cause torque reading to be incorrect,

 

[Ponchoguy]

Sorry, my camera isn't taking photos well, so I guess I'll try to describe as best as possible.

Should have been a simple morning, rear brake pads on my wife's 03 Honda Element with 210k miles.

Everything is fine until I go and put the wheels back on, one lug nut makes the impact hammer a lot, take it off and I notice the stud has a single thread that is bent over a bit.

So I get my craftsman (Kasbar/Lang) 12x1.5 thread restorer tap and die out, all done with oil. The tap went through the lugut a few times and is now smooth. But the restorer tap itself now has one thread that is sheared off. The die went into the stud and does its thing. After everything spins smoothly with the die i notice the stud thread is bent over into the valley of the thread rather than straightened out i try to spin on the lug nut anyway - no go. Do the same thing again for no apparent reason, and get no different results.

Well thankfully I got myself a craftsman 12x1.5 die. The real cutting die type. I spin that onto the stud back and forth twice and it removed the bent thread out of the valley of the lug stud. Everything fine now.

Just kind of annoyed a buggered thread was fixed easier with a cutting tap/die set rather than with a restorer set.

Why wouldn't you just change the studs and/or lugs?

 

[sonvolt]

not the correct tool to repair threads Taps and Dies are for cutting new threads, using a tap or die removes metal and will cause torque reading to be incorrect,

Depends on how bad/rolled over the threads are. The die will follow the good threads without removing any pitch material of the thread. I've done this a million times with a tap and or die. That craftsman thread tool is light duty.

 

[ajchien]

Why wouldn't you just change the studs and/or lugs?

Good question. I was working on my driveway, and I didn't have either new lugs or studs.

The lug will be easy to change next week.

As for the studs, I'm not experienced enough with the rear wheels on the Honda Element. Can anyone tell me if they'll hammer right out and back in, or are they like the front where they'll hit into the wheel hub requiring partial disassembly?

 

[Ponchoguy]

Good question. I was working on my driveway, and I didn't have either new lugs or studs.

The lug will be easy to change next week.

As for the studs, I'm not experienced enough with the rear wheels on the Honda Element. Can anyone tell me if they'll hammer right out and back in, or are they like the front where they'll hit into the wheel hub requiring partial disassembly?

A lot of times, Dorman makes them with a "half moon" base so they can be snuck in through the back and pulled into place. I guess enough techs wrote their tech line telling 'em they were grinding them to fit. LOL.

 

[ajchien]

Generally, you'll not know this, but a rule of thumb is 1xdia of bolt = minimum length of thread engagement. Less than that engagement can result in loosening bolted joints over time. I design myself for at least 1.5xdia of bolt = min thread engagement length along the bolt to be safe. - Paul, ME on the side

thanks for the rule of thumb. I'll keep that in mind when deciding when to replace vs. repair.

 

[ajchien]

A lot of times, Dorman makes them with a "half moon" base so they can be snuck in through the back and pulled into place. I guess enough techs wrote their tech line telling 'em they were grinding them to fit. LOL.

Seriously. I never quite warmed up to the idea of grinding the stud to make it fit past the hub assembly. Can you find me a link of such a product? Google has failed me.

 

[pauls_workshop]

thanks for the rule of thumb. I'll keep that in mind when deciding when to replace vs. repair.

Sure thing, also, "thread engagement" is what threads on the male side are actually in contact with the threads on the female side when bolted together with design torque. Not always obvious, as the male side or bolt/stud side will always have extra threads there not used in contact with the female side. So it can be a little fuzzy to actually try to figure that out in practice, unless you can see clear witness marks of the threads actually in contact when engaged. Easier when you are designing a bolted joint in the first place! And my rules of thumb are worst case arithmetic stackup tolerances too, not statistical stacks, for those engineers amongst us. Best to err on side of caution with bolted joints, esp. critical bolted joints. I've never designed a wheel bolted joint, so don't know industry practice there exactly, just what I would do.

Also, hint for all: It is always a better bolted joint if there is less friction present between the threads in engagement during the torquing process. Add just one or two drops of oil to the first few threads on the bolt/screw/stud or else a whiff of graphite powder to them before torquing the joint tight. You will realize in practice more actual force keeping the joint together for the same torque applied with less friction between the threads. Especially if you are re-using parts with any damaged threads present or loss of material in the threads from using proper tap/die on them to fix, this would help make up for it. Probably about a 10% improvement in force from doing this. - Paul, ME on the side + and now with my first actual patent this year !

 

[Ponchoguy]

Seriously. I never quite warmed up to the idea of grinding the stud to make it fit past the hub assembly. Can you find me a link of such a product? Google has failed me.

Rock Auto should list them or Dorman (Motormite, R&B) is the company. My old boss worked/works there and tried for years to get me to go there.

 

[OutsideMachinist]

not the correct tool to repair threads Taps and Dies are for cutting new threads, using a tap or die removes metal and will cause torque reading to be incorrect,

Yes it will change it but as others mentioned not significantly unless it is significantly damaged. If that is the case it needs replaced. I was talking in general for any stud, nut, or bolt. I wouldn;t tap a lug nut unless it was an emergency temporary fix id just replace it. I would run a die on a lug nut stud unless it was completely trashed. It cuts yes but only removes a tiny amount of metal in the damaged areas.

We do it everyday and never had issues. That set is good for the average guy but it is very light duty. Depends on the kind of metal you are trying to fix as well so there are lot of variables. Lubrication can change the torque more significantly. Lug nuts pretty much are never lubricated or accounted for being lubricated as far as I know. Almost ever torque spec I deal with accounts for lubrication as well whatever type it may be.

Thread restorer sets have limitations is all I am saying.

 

[M6erfan]

+1 on not using a cutting die for restoration
+1 on replacing the stud if bunged up, cheap and easy fix

I've had the craftsman thread resto kit for years and it's one of my favorite tools in the shop. I do a lot of restoration work and try to re-use original fasteners when I can. I've used that kit on literally hundreds of threads. Wouldn't want to be without it, but need to understand its limitations.

 

[pauls_workshop]

Lubrication can change the torque more significantly. Lug nuts pretty much are never lubricated or accounted for being lubricated as far as I know. Almost ever torque spec I deal with accounts for lubrication as well whatever type it may be.

Hey Outside: Lubrication can't change the torque. The torque is what the torque is when the wrench is in the hand turning the bolt/nut. It will increase the clamp load force in the bolted joint for the SAME torque, if friction is reduced during the tightening. Adding a bit of oil/graphite under the bolt head is another benefit for traditional bolts also, as there is quite a bit of friction not only between the threads but also between bolt head and mating surface as it is torqued down. Generally, an assumed friction is used when torque specs are created. Reducing that gives you a better bolted joint. Only issue is if one has very poor grade bolts or defective bolts that could not handle the 10-20% increase in the clamp load. This is rarely ever the case. - Paul

 

[justanengineer]

not the correct tool to repair threads Taps and Dies are for cutting new threads, using a tap or die removes metal and will cause torque reading to be incorrect,

+1 on not using a cutting die for restoration

Most tradesmen use taps and dies for thread repair, you'll very rarely ever see a "thread restorer" in a professional shop bc theyre more of a hobbyist's novelty than a useful tool.

Realistically there's no reason not to use a tap and die set if you're capable and have a decent set. A thread restorer is simply a tap or die with extra thread engagement (not the thread depth Paul's discussing btw). Yes, if you use a common low quality set with an unknown thread engagement as is sold in Sears or off the tool trucks you may cut metal bc those sets typically have high thread engagement to help novices/inexperienced folks make good threads despite wobbly cutting tools. However, if you have some known quality manufacturing taps/dies cleaning up threads is ez-peezy. Ive got hundreds (maybe thousands) of taps and dies, I simply try to spin the tap/die a few threads by hand without a handle first. If I can, I know I'm not cutting metal. If I cant, I either loosen the engagement of an adjustable die/tap or grab another until I find one that will.

 

[Tinner]

Most tradesmen use taps and dies for thread repair, you'll very rarely ever see a "thread restorer" in a professional shop bc theyre more of a hobbyist's novelty than a useful tool.

This. In 40 years I've never seen them used in a professional environment. It can however, be difficult to convince an amateur who has been sold some marketing bs...

 

[Indexmill]

How about using a socket and maybe a ratchet to INSTALL the lug nut rather than using the impact gun?? Pretty difficult to cross thread when tightening "by hand". I never impact on; always hand start. If that goes far enough, then use the power.

 

[M6erfan]

I was told long ago by a engineer/machinist that using a tap/die for thread resto may remove material which may not be a good idea for the task at hand. Maybe he was wrong but thats what I've gone with for nearly 20 years. This "amature" never had an issue with the "BS marketing" thread restoration set...

I have a good tap/dies, I don't use them for thread restoration

 

[jrobb316]

We are not talking precision stuff here, its a lug stud. Get a new lug nut, because those threads almost never straighten out right, and run a die on the stud. Honda studs are generally a PIA to replace because the hub is so close to the knuckle and you can't angle a new one in without pulling the hub a little bit. Though rears are easier than the fronts. Ive straightened out way worse than one bent thread with a die and new lug nut. Honda dealer tech for 15 years.

 

[Skin]

Most tradesmen use taps and dies for thread repair, you'll very rarely ever see a "thread restorer" in a professional shop bc theyre more of a hobbyist's novelty than a useful tool.

Its not a novelty, sometimes thread restorers are the only things that fit so it should be in your tool box for that reason alone. They're substantially smaller than your standard 1" die.