Micrometer recomendations

[anndel]

I'm getting ready to do a bunch of brake jobs on my wife's car and our 1993 Toyota pickup in a few weeks. Any decent Micrometer recommendations? Mitutoyo? Starrett? Performance Tool? Thanks

 

[OkRider]

Starrett or Mitutoyo. But I believe automotive brake rotor micrometers are supposed to be pointed on the contacts as opposed to conventional machinists micrometers.

Drum brakes obviously require an ID micrometer set that has the appropriate range.

 

[hautpot]

I would not use a new mit or starrett on brakes. You are going to want a *********** micrometer with a round anvil. A mechanical
mic should serve you well.

 

[Wayfastwhitie440]

Central tools is what I've used for years, and yes they are specifically for brakes. Just type in brake rotor micrometer. Are you just trying to see if there in specific or you plan on turning the rotors? In most cases rotors are cheap and I would just replace them.

 

[scissorman]

I would buy a Mitutoyo Micrometer if you can find the correct one (Disc brake Micrometer). Here is a Fowler version for what you want. http://www.autozone.com/1/products/...icrometer-fow72234422-fowler-fow72234422.html

 

[scissorman]

Central tools is what I've used for years, and yes they are specifically for brakes. Just type in brake rotor micrometer. Are you just trying to see if there in specific or you plan on turning the rotors? In most cases rotors are cheap and I would just replace them.

I was an Automotive machinist for 22+ years and even new rotors should be machined, 98 out of 100 were warped straight out of the box.

 

[anndel]

Central tools is what I've used for years, and yes they are specifically for brakes. Just type in brake rotor micrometer. Are you just trying to see if there in specific or you plan on turning the rotors? In most cases rotors are cheap and I would just replace them.

I'm just checking if they're within specs (thickness) and if not will replace them with new ones. Thanks

 

[Rosso]

I've been looking at a quality micrometer too myself, why would it need to be a pointed end for checking disc's rather than a standard flat end ?

 

[Eastsidetech]

I've been looking at a quality micrometer too myself, why would it need to be a pointed end for checking disc's rather than a standard flat end ?

The pointed ends are needed for techs that plan to turn rotors if within spec. This is used to measure to the thinnest spot when they have grooves, even if the grooves aren't noticeable. Flat tips just don't get into the grooves. But if you are either leaving them on without turning or replacing then any mic will work. Although if there are any grooves or one deep one I'd replace if you don't have access to a lathe.

 

[Greatwhitewing]

I was an Automotive machinist for 22+ years and even new rotors should be machined, 98 out of 100 were warped straight out of the box.

How far out do you find new OEM quality rotors? I am asking about good or best quality rotors, not the cheap ****

 

[bob15]

Brown and Sharpe micrometers. Buy one that goes to .0001", even if you don't need that precision now; it is always nice to have the extra accuracy reading ability.

As for measuring the old rotors and re-using them.....just replace them. You will need to buy a *********** micrometer for an accurate measurement.

 

[sberry]

I have done 500 brake jobs, never used one. If you have several jobs to do and they are working fine but for pads do yourself a favor and clean any ridges or trip the edge of the pad so they seat and toss the cheapest pads you can find on and call it a day.

 

[sberry]

I was an Automotive machinist for 22+ years and even new rotors should be machined, 98 out of 100 were warped straight out of the box.

While this may be true it should be taken with caution. Putting them on the avg old brake lathe with the avg operator isn't going to help and that little warp doesn't hurt squat anyway. We can see by a steady stream of issues here giving more to worry about and research the more the confusion.
What is true about 98% of the time its usually something someone done to it. Once they work on it its never the same. Everyone things they drive harder than the next guy or mother inlaw needs some after market exotic **** measured within a gnats *** has problems. Most who rave how well exotic equipment works really don't use it.
There may be a rotor cheaper by a couple dollars but the white box rotors on the shelf at major chains and decent parts stores when it needs one along with generic brake pads is the most reliable thing a guy can do to insure a good job .
No fukkin around, no micrometers, no turning, no guessing after reading endless forums with some accurate but poor advice from guys really should know better.

 

[GirchyGirchy]

I'd go with Mitutoyo, best bang for the buck IMO. We have several at work and have never had an issue with any of them.

At home I have a nice Mahr (got a great deal on it) and an older digital Starrett which is ****. I use the Starrett as the "beater" set for dirty stuff (like brakes!).

 

[Showkey]

I would say a dial indicator to check rotor run out would be needed too. And maybe more important ? They (runout and thickness variation) are both important ............

Depending on much thickness variation there is ........it might show up on the run out check.

Auto parts store often have free loaner tools.

If the rotors are not scored, grooved, rusted and the pads are just worn .......some guys will install new pads and see how things work. If you already have braking vibrations the rotor needs to be addressed.

Obviously caliper service is also needed on some jobs. Some service locations will try to sell everyone calipers .......those $98 per axle ads........that lead to $600 or more per axle.

If we are just checking for minimum rotor thickness a caliper would be just fine.

 

[JUNK-MAN]

I have two Starrett's, they're great.

 

[sberry]

If a guy is serious enough about maintenance he wont need a micrometer. He will be doing wheel off brake service during tire rotation to insure the hardware is functioning, there is pad left sufficient till next service, its running square, some general inspection and most factory rotors will outlast a couple sets of pads and not sure how the salt air treats it all but paved parking etc the stuff could go a long time.
We replaced a set a while back, regretted it, was damage to a rear one causing all the problem and the factory would have outlasted the car.
My Dad had a mini van and the pad busted out of it, grooved the thing. . The thing was rather new just around warranty maybe and the rotor was not on the shelf so we tossed a pad on it and bought a rotor thinking at some point we would change it out with the new pads. I used 2 more sets in th life of the unit and still have the new rotor in the box on a shelf.

 

[Showkey]

Some times you do not have measure the old rotor.

 

[sberry]

Keeping the hardware sliding is the number 1 thing and most neglected. It should have been serviced well ahead of most problems. My Dad has new car, the rotors look horrid at 11K, we will see how long it goes, my guess it will have very little effect on pad life. They are well grooved and finish long gone already. In a week would have ruined the finest machine job one could have given them.

 

[Davefr]

I wouldn't buy a micrometer for just two brake jobs.

If the old rotors are not warped nor have deep scratches and have not been previously turned then re-use them. (Having rotors turned at every brake job is no longer recommended by many auto manufacturers.)

If the rotors are badly warped then replace them. (turning a warped rotors often causes the warp to return since the rotor is now thinner).

If you still want the rotors turned, the machine shop you take them to will measure them for you. (or any parts store that turns rotors).

Take the money you'd spend on a micrometer and buy premium quality parts.

 

[Kevin54]

Micrometers are a preference tool, but there is no difference between the brand names really. The only real difference between mics I have seen in all my years are the Brand names we are used to compared to Chinese Mics. But even the Chinese mics are a good mic, but to me the set I have, the numbers are hard to read for me.

And someone mentioned above about measuring pads with a pointed mic. You are better off reading the pad with a flat measuring face. Reason being, if one likes to gorilla twist the mic, you will dig a point into the pad, and can be upwards of .005+ off of what they actually are. A flat face won't let you dig in, and will give you a better reading. Also, you are not taking up much revenue to vary that much. If anything, I would check the surfaces with a ball mic. Less surface contact on both sides, but will not dig in.

For one or two brake jobs, I would not invest into a set of mics, unless you want a set laying around. If you do purchase a set, you can buy used as long as they come with a set of "Standards". This is what you use to verify that the mics are set correctly. A Chinese set of mics will be a reasonable cost at either new or used, but like in what I found was they were harder to read for me. Not in the way the dial is set up, but the print was just a little smaller.

 

[Dennis Leigh Henry]

I've used and trusted Starrett. but also own Brown and Sharp, Lufkin, and Mitutoyo.. I've always used the old fashion analog ones, as digital have been sketchy over the years..

eBay have hundreds for sale...if not thousands new and used..

 

[Kensgarage]

It's a break rotor. Not a crank in a 1000 HP hemi. Buy the cheapest micyou can find. Close enough.

 

[bob15]

It's a break rotor. Not a crank in a 1000 HP hemi. Buy the cheapest micyou can find. Close enough.

Why buy the cheapest mic?

You never know, in the future he might find a need for it which requires better accuracy and he has to go out and buy another mic. Buy a good one now, and be done with it. E-bay has very nice used .0001" mics for $ 30-50.

 

[scissorman]

How far out do you find new OEM quality rotors? I am asking about good or best quality rotors, not the cheap ****

Just about every new rotor has been out around .008"-.010" and it only takes .006" before you have issues. Also most of the new rotors have not had parallel surfaces either. These rotors are made and then shipped multiple times and banged around each time so you'd be extremely lucky to find a rotor that doesn't have runout of some amount.

 

[sberry]

Some times you do not have measure the old rotor.

Sadly much of the problem is that many can not distinguish that and a few thousandths.

 

[sberry]

I know smart people drive it in to that condition. A used brake pad when they got the truck would have been cheap. Many that buy decent used cars are the worst. I tell them the day you get it should be the day it goes to the shop for a complete physical. These cars are often referred to as "new cars".

 

[sberry]

I always wonder, I got all this stuff, I got micrometers and a simple digital caliper has really replaced it all.

Why buy the cheapest mic?

You never know, in the future he might find a need for it which requires better accuracy and he has to go out and buy another mic. Buy a good one now, and be done with it.

But I have about everything to sustain life, we got a mic or 3 so the mechanic pulled one out the other day for a specialized engine which was ruined so anything within a couple thou would been sufficient,,, but where would the avg Joe even need to measure something within a thousand???
WTF you guys work on you need precice equipment? Chances are he already doesn't have an HF digital caliper, start there, its about like the cherry picker and come along, most can find some use for it.
Play around with the HF caliper to get a feel for what a few thousands is. Even doing engine work, a guy can feel a cylinder and tell if it needs to be bored.
The place I can recall using the caliper is golf cart valves, sandng the little thingy a couple thou and its plus or minus .004.
While a guy was there could get a set of telescoping gages at that price. Those would be the first 2 tools and see if a guy really needed anything beyond that.

 

[bob15]

I always wonder, I got all this stuff, I got micrometers and a simple digital caliper has really replaced it all.

But I have about everything to sustain life, we got a mic or 3 so the mechanic pulled one out the other day for a specialized engine which was ruined so anything within a couple thou would been sufficient,,, but where would the avg Joe even need to measure something within a thousand???
WTF you guys work on you need precice equipment? Chances are he already doesn't have an HF digital caliper, start there, its about like the cherry picker and come along, most can find some use for it.
Play around with the HF caliper to get a feel for what a few thousands is. Even doing engine work, a guy can feel a cylinder and tell if it needs to be bored.
The place I can recall using the caliper is golf cart valves, sandng the little thingy a couple thou and its plus or minus .004.
While a guy was there could get a set of telescoping gages at that price. Those would be the first 2 tools and see if a guy really needed anything beyond that.

For work use: all the time. Also will use a shadow graph and a P&W Supermic

For home use, besides working on an engine?

casting bullets: micrometer
reloading ammo: calipers
measuring drill bits: mic or calipers

 

[Dennis Leigh Henry]

Sadly much of the problem is that many can not distinguish that and a few thousandths.

This is the owner who liked to have baseball cards close-pinned to his bicycle to make that very noise....

 

[Rubiman14]

I deal with .00005" tolerances at work and have an extensive QC lab at my disposal. The best mics I've ever owned are an old B&S #1 with angled hash marks that I bought off ebay. Digital mics are horrible! Even then, the best mics on the planet will not teach the proper "feel" needed to be really accurate. The other problem I see is people rarely buy a gauge block/pin to keep them zero'd (preferably ** class). Because of that I feel most people are better off with a pair of quality dial calipers. If you truthfully have a need to measure within .0001" then by all means buy some mics. Rotors do not need to be measured that precisely.

 

[bubinga]

Some times you do not have measure the old rotor.

OMG!!!!!!!!

 

[scissorman]

That's the open vented rotor design. LOL

 

[darkzero]

Those are the new style slotted rotors to run these days, cross drilled is so 90s.

 

[SGKent]

when you take it to the machine shop to have it turned they will mic it for you. Generally you can just replace the pads the first brake job and then replace the rotors the second time. By then it will be close to minimums and in my experience new rotors will stop better than really thin ones. Sometimes I'll buy a new set of rotors on the first brake job, then replace pads and rotors, and take the set I took off to be turned. Next job put them on and take the second set to be turned at my convenience. That is good for close to 200,000 miles so at that who cares, time for a new car.

 

[d.mcfarland]

Been 5 years since that picture was posted. They are probably due for another brake replacement.

 

[mowkep]

I have a pair of Starrett 0-1 mechanical digital mics in the classifieds