Dial Test Indicators
In Brief: the best dial test indicators are Swiss made. You have 4 commonly available brand names to choose from: Bestest, Compac, Interapid, Tesatast. All of these are made by the same manufacturer in Switzerland. There's nothing better on the market, in our opinion. (We should add Girodtast which is the only Swiss-made indicator not made by TESA.)
The worst dial test indicators are Chinese, Japanese and - sorry to say - American. We'll let you figure out the manufacturers in question.
Notes on Manufacturers
Accupro vanity dial appears on indicators made in China and Germany. The Chinese indicators are worthless and can not be repaired. The German indicators are the Puppitast series made by Mahr-Federal.
Alina (Switzerland) indicators were made by Compac until the mid-1960's. They are no longer available and spare parts are exhausted. The Alina Model 88 indicator was a superior version of the American-made Last Word indicator.
Baker (China) indicators are cheap throw-aways for which parts are not available. We have been told that they are somewhat longer lived than other Chinese brands. Replacement contact points are not available but Compac points will fit, in a pinch.
Baty (Swiss) indicators are a vanity dial on Girodtast indicators. (see below)
Bestest (Switzerland) has become America's favorite and there's good reason. They're among the very best available; a great value for the money. Excellent repeatability and quick response make them desirable. If there's a drawback, it's that they're prone to damage because of the light construction. Available in black or white, horizontal, vertical or parallel. Except for the name on the dial, they are identical to Tesatast. Distributed in the US by Brown & Sharpe.
China If you're buying indicators made in China, you're scraping the bottom of the barrel. You can't get any worse. Some years ago we were hired to evaluate these indicators for MSC who wanted to know if they were worth importing. Apparently they didn't listen to our advise. Now, of course, they’re making a killing selling these. Dovetails didn't fit and brand new .0001" indicators wouldn't calibrate. It turned out that dovetails didn't accept anyone else's attachments because they were oversized. Pass on these and order some Take-Out instead (but skip the chicken feet). Available in catalogs everywhere but don’t expect to find any spare parts.
CDI (Chicago) test indicators are identical to Compac (Switzerland). These were made for CDI in the 1980's. CDI no longer sells them but you can buy the Compac replacements.
Compac (Switzerland) has been our indicator of choice for over 4 decades. These are sturdier than Bestest and less finicky (and less costly) than Interapid, even though they're made by the same manufacturer. Of particular note are the extra long range of some of the models. Model 215GA (.0001") and 225GA (.0001" vertical) have dials with extra wide spacing between graduation marks. This is a feature that many owners appreciate. Dials are continuous reading on long range models, balanced on standard range. Contact points will swivel, like other indicators, but you may encounter more friction than you are used to. It's okay to apply the extra force. The indicator's over-sized pivot can take it. Long Island Indicator stocks new Compac indicators as well as repair parts.
Craftsman indicators are sold by Sears but are often times made in the UK in which case they are identical to Verdict indicators. They're not very good (in fact, they're downright awful) but do offer the "pear shaped" contact point which makes them look quite medieval and eliminates the cosine error, in theory.
Federal Gage made the worst test indicator you could get stuck with. Blobs of solder were used to hold it together. Mercifully these have been discontinued. The last models named Testmaster were made by Tesa in Switzerland and they're identical to Bestest indicators (see above). These are no longer available from Federal, but you can still buy the Bestest equivalent. The newest indicators are called MarTest (see Mahr-Federal).
Fowler once relied heavily on English imports such as Verdict indicators. These are about as good as English weather. Nowadays they rely more heavily on Swiss made gages but also offer look-alikes in their effort to remain competitive. Beware of wolves in sheep's clothing: they offer a pathetic imitation of the Bestest indicator and an Interapid look-alike is made in China and sold under the name Xtest. The best mechanical test indicator which Fowler offers is the Swiss made Girodtast. When shopping Fowler, if it doesn't say "Swiss Made" don't buy it.
Gem (USA) makes an inferior version of the popular Starrett Last Word Indicator. This would be fine if they were cheaper. There is an odd variation, however: one model has two dial faces, one on each side. This comes in handy in some applications. Some of the newest models have replaceable dove tails. Gem also manufactures a line of indicator clamps and holders.
Girodtast (Switzerland) is similar to the old style (1970's) Bestest indicator with some improvements to make them sturdier. In the USA these are sold by Fowler. In Switzerland they are also sold with the name SISO-Tast. If you've ever wanted a Bestest indicator with multiple revolutions, Girod offers several models with extended ranges. If they have a drawback, it's that the contact point is adjustable. You'd think this were an advantage, but for most people it's a nuisance. On the Bestest you simply unscrew the old, screw in the new. On the Girod-Tast you have to adjust the new point so that the indicator is in calibration.
Interapid (Switzerland) is the gem of all test indicators. These have the distinctive slanted dial which the other manufacturers have only just begun to copy. Correct readings are obtained when the contact angle is 12°. Undoubtedly this has its advantages as long as the user remembers to take it into account. The revolution counter hand does not have any numbers associated with it. There are just a couple of tick marks showing you that you've gone around once or twice. Dials are balanced and the right side of the dial has a thin black line which will help you determine plus or minus in a mirror set-up. A 4 mm diameter holding stem is permanently attached to the far end of the indicator. Models with 2.8" long contact points tend to have a slower response and should probably only be used to measure .001" (Note: beware of cheap Interapid look-alike ripoffs now being offered in catalogs. They're made in China and they're junk. Insist on the real thing.)
Johnson Gage test indicators of the 1950's and 1960's were made by Compac, Geneva. They were the same as those sold under the Alina brand name (see Alina, above). They are obviously long obsolete.
Kafer (Germany) (also spelled Käfer and Kaefer) manufactures a complete line of test indicators with one revolution. These are beautifully crafted and come in a box with a clear lid, so you can easily see what you're taking off the shelf. Alas, they do not have identifying serial numbers. An excellent alternative to Swiss-made indicators but model styles are limited. Parts are available but rarely does anyone stock them.
Kurt (USA) although located in Minneapolis, these are generic made-in-China imports. They're cheap throwaways although Kurt claims they're of better quality than other Chinese indicators.
Last Word (USA) Starrett makes this stalwart and ubiquitous test indicator without resorting to toothed gears. Although usually accurate we've seen enough of them that compare poorly with the better built, gear driven indicators to warrant skepticism. The body on older models, being made of iron, rusts easily and will become magnetic (and sticky as a result). Newer models are black anodized. A recent manufacturing change makes repairs impossible if the pivot screw breaks off although the new, one-piece crystal is easy to replace. We do not hesitate to classify this indicator as the worst of its kind.
Lufkin never manufactured any of their own indicators. In the 1960's they had a vanity dial on the Alina indicator. These tended to have model numbers such as V60X. It was never clear how they managed to usurp Alina's exclusive rights to these gages and that may have been the reason the line was finally dropped. Repairs are no longer possible due to the obsolete parts.
MarTest manufactured in Germany by Mahr-Federal. These are made with classic German craftsmanship. These test indicators have the contact point length conveniently inscribed on the side of the case. We find that the .0001" indicators may be too sensitive for some users. The contact point swivels very easily and this can cause problems with repeatabiltiy. The bezel turns on a rubber o-ring and this has sometimes dried out on us creating much too much friction for comfort.
Mahr (Puppitast) manufactured in Germany, part of the pre-Mahr-Federal conglomeration. These are structurally similar to Bestest, Tesatast and Girodtast indicators. The handsome bodies are somewhat sturdier and have textured sides which might, under some circumstances, keep them from slipping out of your hands. The crystal can rather easily be replaced without tools and this is an advantage over Bestest and Tesatast. Discontinued.
Mercer manufactured in Switzerland but for some reason the dial sometimes reads "England" (possibly because they are trying to use up old dials). These are manufactured by Tesa for the English market and are identical to Compac indicators (see above) with the obviously different dial. Mercer offers several configurations not found in the Compac line. They are available from Brown & Sharpe distributors by request.
MHC Industrial Supply made in China. Whenever the country of origin is not printed on the indicator dial, you can be assured it's Chinese. For some reason they can get away with that.
Mitutoyo new models, completely redesigned, are manufactured in Japan. Some models are available with optically scannable serial numbers on the dial face. The new "pocket" models 513-512 and 513-518 are a major improvement in design and construction over the old models and can be recommended. The other models don't compare with their European counterparts. The newer slanted dials which mimic the Swiss Interapid indicator have one significant difference: they are accurate when the contact point is used at an angle of 0°. This could be a source of confusion—and error—in a shop which uses both brands. Because of their often low list price, these are best considered "throw-away" indicators. Repair are likely to be uneconomical. To prove the point, the manufacturer uses epoxy on some of the assemblies, making them virtually impossible to disassemble.
Mueller old models were made in England.
Nork indicators were manufactured in Manhattan of all places, by General Howe Mfg Co., Inc. They're a dreadful imitation of the Starrett Last Word indicator although they did have a much more functional reversing lever.
Parvus indicators were manufactured in Switzerland and sold in the US with the Alina name on the dial. These were later transformed into the Compac models. You may see the word Parvus stamped on some of the old bodies. Long obsolete (1950's), there are no parts or repair service available.
Peacock (Pic-Test) manufactured in Japan. This is a meager entry in the test indicator market, designed along the lines of the old model Bestest. Comparison ends there, however. Calibration often has to be fudged by changing the contact point angle on the .0001" model. Newer models contain plastic gears. They are available from some catalog houses but parts are generally unavailable.
Shars generic indicator made in China (see China, above)
Sisotast manufactured in Switzerland. This is a vanity dial for the Girodtast indicator. The indicators are identical with the exception of the dial.
SPI (China) manufactured for SPI. These are generally the same Chinese indicators you can buy under any number of other "brand" names. The cheap price gives them away. SPI stands for Swiss Precision Instruments. Don't let this fool you. These are not Swiss and their precision is short lived. (SPI used to offer genuine Swiss indicators with the SPI name. They were made by Compac and you can still get them. See Compac above.)
Standard Check-Master manufactured in Poughkeepsie, a long time ago. This indicator was like the Federal TestMaster design only much better. It was elegant and beautiful in comparison. Parts and service are no longer available on this long obsolete item.
Spot-On made in England, looks for all the world like an old Verdict indicator. These are obsolete and may date back to the 1940-50's if not earlier. Starrett Last Word would be an acceptable replacement if you like this style. Refer to page 117
Starrett (USA) would like us to believe that they are products of the USA. The origins of some of their indicators is vague, however. Model 708 for instance is only marked as "American Made." The revolution counter hand has "0-1-2" markings with no indication of actual travel. On this same model you will have to fuss with the contact angle to find the right spot for accuracy. Half the dial is yellow and half is white. This comes in handy when reading the dial in a mirror. (Yellow does not indicate metric graduations in these models.) None of the Starrett test indicators is in the same league as their European made counterparts and we consider model 811 to be among the worst indicator designs available.
Teclock (Japan) You can often buy European-made models for less, and you'll get better quality. Spare parts are not commonly available. These indicators are heftier but feature an inferior execution of the Bestest-style mechanism. The newest models seem to come with plastic bezels. When the crystals are scratched, or the bezel breaks (it will) you won't be able to replace them. None of the Teclock test indicators is in the same league as their European made counterparts.
Tesatast (Switzerland) manufactured by Tesa are identical to Bestest with all the same good features. The accessories that come with the indicator are different. We have all parts in stock.
Testmaster (USA) an indicator made by Federal Gage and discontinued, mercifully, in the 1970's. This was one of the worst designs and executions of all time. Blobs of solder were used to keep the return spring in place. Unbelievable.
XTest (China) manufactured for Fowler as a rip-off on the high-quality Interapid indicator. They look so much alike in the advertisements that many people are fooled into thinking they're getting a terrific deal on the Swiss indicator. You get what you pay for. In this case, a pathetic imitation.
(16) Calibration: A few test indicators can be adjusted for calibration. Some have contact points with set screws so that, in effect, you can shorten or lengthen the point to adjust calibration. Others have internal cams that can be adjusted. Both procedures require jeweler's screw drivers, good eyes, patience and some intuitive algebraic skills. Since new indicators are factory calibrated, this feature is rarely needed by the end-user but could prove helpful in the repair shop.
(17) Waterproof?: Because the contact lever has to go into the indicator body, the test indicator can not be liquid proof. However, some models offer a bit more resistance to the ingress of liquids than others because the entrance into the body is smaller thus fending off liquid sprays; and, the bezels offer a tighter seal. If liquid contamination is an issue, then you may want to consider these factors.
(18) Serial Number: To comply with ISO stipulations and to make identification possible for the employer's records of calibration a permanent serial number is required to be stamped or engraved somewhere on the indicator. Mitutoyo has gone so far as to add a miniature scan code on the dial face which can eliminate errors of transcription. If the dial is changed during repairs, however, the serial number is lost.