Dial indicator purchase help

Hi guys,

I think I need a dial indicator to help me tram and check runout on my router etc.

But I’m a bit confused between a dial indicator and a dial test indicator.

What do you guys use or recommend.

I have been looking at the mitutoyo ones but the sheer size of their range makes it hard to choose as the have different reading scales etc. sizes and then accuracies.

Being from Australia I am looking at metric versions.

I was think the 0-5mm range should be more than enough for the amount of deflection etc, would be more than enough travel.

Price wise around $200-250 Aud so probably $150-180 Usd.

Any advise is appreciated.


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Dial indicators and test indicators are different beasts indeed.
I don’t own fancy Mitutoyos but the cheap ones I got are enough for casual checks, so I’ll explain it with my naive hobbyist words, and actual machinists can chime in to provide better answers.

Dial indicators (up/left) typically have a plunger with a relatively large travel (mine has 10mm travel), so they are better suited at measuring potentially large deviations, for cases where you don’t know for a fact that the difference you want to measure is very small. Typical uses I know of for CNC are:

  • mount one on an arm, at a distance from the router, to detect variations in Z on the wasteboard between left/right/front/back position, for tramming.

    (oh my, I now realize that based on that drawing someone could end up thinking that the router is used to spin this thing…no no no no :smiley: )
  • mount one on a stand and move it against one part of the router for example, to either calibrate the number of steps per mm (by e.g. jogging 5mm and checking what the dial indicator read), or check for backlash/slop:

Test indicators (bottom/right) have a lever mechanism instead of the plunger, they typically have a very small travel (mine has about 1mm of travel) but higher resolution (not mine…it’s 0.01mm just like my dial indicator). They are better suited for detecting subtle variations when moving the piece under the test indicator. The typical example I know of is measuring runout on the shaft of an endmill:

Manually rotating the endmill will have the test indicator tip going 360° over the endmill shaft, and the readout will show any variation (runout)

I usually tend to spend good money on quality tools (and buy them only once), but since I had no idea what I was doing (and to some extent still don’t) I went for those cheap models and they happened to do the job so far, definitely accurate enough for tramming purposes. But if you can afford Mitutoyos I would say go for it, I have exactly one Mitutoyo tool (caliper) and I still can’t believe how much better it is compared to every other cheap caliper I have owned.


You owe it to yourself to at least get a Mitutoyo rule (or a Starrett (see if you can get a vintage one in good condition?), or at the least a PEC blem. such as Harry Epstein Hardware sells: https://www.harryepstein.com/closeouts.html?brand_for_product_detail=2702 )


It is really easy to go overboard on the measuring tools. Trust me. This is the voice of experience (does any one person really need six 1 micron precision test indicators?)

There is value to buying the best you can afford that meets your need, but, to be honest, for some things, the bargain units are fine. I have a mix from the least expensive no-name import to Mitutoyo, Starrett, B&S, and Interapid. The cheapies get a lot of use, and this reduces risk of damage to the more expensive ones.

Short answer: for tramming, get a 10mm range inexpensive standard dial indicator -with an actual needle, not electronic. (I don’t know what you have for suppliers, but in the US, Shars would be one option, or even Harbour Fright) It will be small enough to fit, large enough to see. If the ring is all one color (most are), color one side. Nail polish on the bezel is good for this. Makes it easy to see at a glance which way the needle is from zero, especially with a mirror.

Flat back or lug back is application dependent. I rarely use the lug back except on a bench instrument.

More detail than you want, probably:

Be careful of chasing too much precision. For a Shapoko, 0.01mm is MORE than sufficient. For tramming, mechanical (with a needle) is best, since you can see it without needing to read it. There are times a digital is handy, when you need actual dimensions, but 98% of the time on a machine (on the bench is a different story, but not actually that different) the mechanical device is the best choice.

There are a few standards for these, including DIN, AGD, JIS, and a few others, but, for the most part, the standards specify how to state performance rather than actual properties. AGD is the exception, in that it specifies physical dimensions of the devices. When buying, read the spec carefully. In the US, no-name import dial indicators (also called plunger type, drop indicators, and a few things not suitable for polite company) are available down to 10mm travel with 50mm diameter faces (AGD size 2-ish) for less than $US20, and I get the impression it is similar elsewhere in the world, though the prices will vary a lot based on import structure (sometimes up, sometimes down… go figure). The least expensive tend to be 25mm or 10mm travel. They are fine for tramming. You will also need a way to hold it, and this can be bought, or, you have tools and can make one (recommended). Most other than the smallest will have a stem that is 8mmOD or 3/8"OD, with 8mm being nearly the rule except in the US.

Smaller and larger units are, unsurprisingly, available, and often more expensive. The smallest I regularly use has a 25mm diameter face, 3.5mm travel, and fits in tight spaces well. I have made a lot of special fixtures to hold these (I have a few- they are CCCP surplus from when the old was being dismantled and sold off overseas by anyone that could grab something during the early 1990’s) over the years. The largest has an 80mm face and 125mm travel (calibrated at 0.002mm over the first 25mm, 0.005mm full range. Opportunistic purchase that has been useful)

Indicators take replaceable tips in many styles (flat, rounded, half ball, points, etc). Most come with a half-ball of roughly 3mm diameter, and this is suitable for general use, including tramming, as long as you are working on a reasonably smooth surface. DO NOT let the tip drop into holes or off edges. The shock can damage the tool.

Note that these devices ONLY provide relative measure. You can fixture them for absolute measure (a comparator stand, for example).

You might want to look at Mitutoyo 2046SB (available for about $US60) if you don’t want to look lower down the price scale. 10mm range, 0.01mm graduation. You can look at the catalogs for the actual accuracy specs, but either will be more than sufficient for anything you can do one your machine. You could also look for a deal on a Compac 512K (about $US200, but sometimes, from reputable suppliers, as low as $US40. Makes me wonder…)


Here is what I have been using for the last 40 or so years. (Ebay Test Indicator AND mag base ($14), dovetail adapter: ($12)



If you are using this for just your wood router, and not to make extremely precise measurements, I wouldn’t bother getting a $200 indicator. I own some high quality dial/test indicators for my job, at a machine shop… but I own some cheap, $20-30 ones from Amazon for woodworking. I know that I cannot trust their measurements to be 100% accurate… however, I do trust them to show relative variation in it’s measurement (ex: tramming, testing runout, etc…). I know that I may measure lets say .010" over 12" on a tram, but that doesn’t necessarily correlate to .010" in reality. That is fine though, because I’m more concerned with getting things close and woodworking does not require extreme precision…


Same here, I have a Mitutoyo 2046S which cost be £38 on Amazon, I looked up the price on Amazon AU and saw that you guys get ripped off even more than us for local prices. I bought Mitutoyo because I’ve used them in the past and they’re Japanese quality. There’s no reason not to buy one of the no-brand Chinese indicators though so long as you can return it if it’s junk.

Anyway, as above, a decent 0.01mm precision indicator with 10mm or so of travel is a decent start whilst you learn to use it, they’re reasonably tough so you are less likely to damage it by mistake whilst learning to use it properly.

I’d suggest there’s more value in getting a decent quality mount / arm for the indicator that fits your intended use as you’ll use the mount quite a lot. The usability, accuracy, precision and repeatability of any indicator depend upon you being able to mount it quickly and effectively. I bought a cheapo mount arm and curse it every time I have to use it.

I also printed some adapters to do things like spindle mounting for tramming;

There are as many inventive ways to mount a dial indicator as there are things to measure out there.


I have a bunch of dial indicators and most are no name Chinese. I have a couple of Starrett ones and a Starrett Last Word. For the me they are all good but I am not launching rockets into space. I bought this recently but have not used it yet.

Back to dial indicators they all work well so spend what you can afford. The high end ones will last longer but I have yet wear one out. A machinist might wear one out after years of use. A petrigeed name does not necessarily make it better than a no name one for occasional use.

P.S. The dual indicator has a 1/4 inch rod and the two dial indicators are about 3 inches apart. I bought it on Amazon but found out that I could have ordered the larger version with a 1/4 shaft. The manufacturer makes a larger dual indicator but it has a 1/2 inch shaft. But you can order straight from the manufacturer the larger one with a 1/4 inch shaft maybe. I went on the site https://www.edgetechnologyproducts.com/ to see if they offered the 6" with a 1/4 inch shaft but only found 1/2 and 3/8. But you could go to the site and call them to see if you could get the 6" dual indicator with a 1/4 inch shaft. I would prefer to tram with 6 inches rather than 3 inches.


I recently got one at Harbor Freight along with a magnetic base. I really don’t know how good it is but to check my waste board it’s fine. Of course I’m only cutting wood and not trying to machine high tolerance parts.


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Ah, thanks all for the input.

Yep only machining wood at this stage, so I don’t need the best I guess.

From what I have understood it looks like I kind of need both a dial indicator and a dial test gauge.

I really appreciate all of the time taken for the replies and advice.

I might start with cheaper mitutoyo that was mentioned above a few times, or its metric equivalent, that should leave me enough $ to get the test indicator a bit later on once I get the hang of it.

Being a plumber we normally aren’t that accurate and probably work to within 5mm. :stuck_out_tongue_winking_eye:


I bought the Mini Pro-Tram a year and a half ago, I chose it because the Pro-Tram is 2" taller and might cause clearance problems.

Good Point. Since there was only the 1/2 inch option on Amazon I did not choose. Reading other posts on other forums it might be possible to get the larger one with a 1/4 inch shaft.

Thanks for all of the advice so far.

@Julien thanks for the images makes it very easy to understand the difference

@RichCournoyer I had a pretty good search on eBay and I couldn’t find the dove tail adapter in your picture or even close. It looks very handy

@enl_public thanks for the detail the 10mm travel and .01 resolution was the info required.

I ended up getting the Mitutoyo 2046SB for $75 aud so a big saving on what I was looking at and still sounds like overkill for my usage case.



Odd, took me 18 seconds…perhaps 20: eBay item number:

161462381500 (Dovetail Indicator Holder)

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Thanks, I was searching Australian stock only. So none were showing up.

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