page 12

www.longislandindicator.com

Long Island Indicator Service Inc
14 Sarah Drive — Hauppauge NY 11788 — USA

Precision Tool Repairs, Sales & Spare Parts

repairs

spareparts

contactus

index

cart

search

Dial Thickness Gage
dial thickness micrometer - medor de espesores

 

 

Quick and easy measurements of small parts and thicknesses are made with these hand-held tools. A choice of resolutions and physical dimensions is available from several manufacturers.

The dial thickness gage is typically used to measure the thickness, in mils (.001"), of sheet metal, plastic, paper, and cardboard. Metric measurements (0.01 mm) are likely to be used for fabric thickness and numerous medical, botanical and biological applications. It's useful for measuring diameters of round and cylindrical objects, tubing and pipes. It will make quick work of determining the diameter of bolts, fishing line and guitar strings. Jewelers are likely to use it to measure the gage of gold wire. It has a lifting lever at the top which you depress with your thumb.

The measuring surfaces (anvils) are flat and parallel. These are used for round or cylindrical objects. Thickness of flat sheets is better taken with at least one of the anvils rounded. Replacing the upper anvil with a round nylon contact point will eliminate some of the danger of damaging glass. Again, various manufacturers offer different models.

Throat depth varies from a fraction of an inch to as much as 16 inches. This will determine how far the gage can be inserted onto the sheet or part being measured. Gages with large throat depths will require sturdier frames to eliminate distortion from weight. For larger throat depths, see Kafer on page 96.

The pocket thickness gage is a miniature version, easily tucked away. These are available with an accuracy of ±.001" or ±0,01mm making them suitable for many applications. This has a lever which you need to slide in order to raise the anvil. A quick and easy to read digital version is available which offers both inch and metric readings.

If you need the dimensions of larger items, use calipers instead. If you need greater resolution and accuracy you may want to use a micrometer. If you need to measure the thickness of coatings in mils or micrometers then use the Coating Thickness Gage available in several different styles (please call for information).

The stated accuracy of the gage is more important than the dial graduations. Most digital instruments mislead with readouts to .00005" but offer accuracy of only ±.001". When shopping for a thickness gage ignore the graduations and focus on the accuracy instead.

As with other gages, the inexpensive models are not repairable. They should be tossed and replaced when needed. Better quality gages are more likely to be repairable because spare parts will be available. You may wish to inquire whether a particular dial thickness gage is worth repairing before you send it to a repair shop.

Measuring force is often an important factor when soft materials such as plastics and fabrics need to be measured. The measuring force will be listed in the manufacturer’s catalogs. In some cases, the manufacturer can modify the measuring force to your particular specifications, but this must be requested at the time of purchase and will undoubtedly result in longer delivery times. In the meter-kilogram-second system, the unit of force is the Newton (N), where 1 Newton = 100 gram-force = 0.225 pound-force.

Other thickness applications include:


Starrett 245 Engineer's Combination Taper, Wire, And Thickness Gage

 


 

Mitutoyo pocket thickness gage

 


Discontinued Mitutoyo thickness gage model 7308

Range

Throat Depth

Resolution

Accuracy

Measuring Force

Order No.

Price USD

.400"

.75"

.001"

±.001"

< 2 N

7308

discontinued**

10 mm

.75"

0,01 mm

±0.015mm

< 2 N

7309

discontinued*

 

*Discontinued model 7309 can be replaced by Kafer J15C shown on this page.
**
Discontinued model 7308 can be replaced by Kafer JZ15C shown on this page.

Although they have slightly smaller measuring ranges, you may also be able to use the Starrett pocket thickness gage shown on this page.

Would you like to see a digital version of this gage?

Mitutoyo dial thickness gage

 

Mitutoyo 7300S shown above

This is the full sized version with guaranteed accuracy, including model 7326S with .0001" resolution. All these thickness micrometers have flat lower anvils (ø.433") and flat upper contact points (ø.394") made of ceramic for longer wear. A thumb-operated lifting lever raises the indicator spindle. A full grip handle accommodates the other fingers of the hand. They are easy to use and the Mitutoyo models are almost always repairable.

You can easily convert some of the newest models of Mitutoyo dial thickness gages to accommodate left handed use. Model 7300 shown above, for example can be converted. We'll do it for you, if requested at the time of purchse. Please inquire if this is possible for the gage you’d like to order. Please note that the letter S has been added to some models. This merely indicates that they are the most recent model made in Japan.

It's possible to replace the upper anvil with a nylon ball so that glass can be measured with less chance of damage to the surface. This must be requested at time of purchase.

These models are also available with a large 4.72" deep throat. (See page 209 for details.) Larger throat depths up to 16 inches are available from the reputable German manufacturer Käfer.

Be sure to check for discounted online pricing often 20-30% below list.

 

Range

Throat Depth

Resolution

Accuracy

Order No.

Purchase Order Price

Internet Discount Price

.05"

1.18"

.0001"

±.0002"

7326S

220.00

check discount

.4"

1.18"

.001"

±.001"

7300S

133.00

96.00 order now

1"

1.18"

.001"

±.002"

7304S

160.00

check discount

1"

4.72"

.001"

±.002"

7322S

188.00

check discount

10 mm

30 mm

0.01 mm

±0.015 mm

7301

129.00

check discount

20 mm

30 mm

0.01 mm

±0.025 mm

7305

154.00

check discount

20 mm

120 mm

0.01 mm

±0.025 mm

7323

167.00

check discount

 

Measuring force for the gages above, where N=Newtons

  • 7301 > 1.4 N
  • 7326S, 7300S > 1.5 N
  • 7304S, 7322S, 7305, 7323 > 2.0 N

Blade anvil thickness gage

 

The following special models have a blade anvil and blade contact. The thickness of the blades are .039", the width is .256" and the height is .197"


Model 7315 with blade anvils above

Range

Resolution

Throat Depth

Accuracy

Measuring force

Order no.

Price USD

10mm

0,01mm

1.18"

0,015mm

> 1.4 N

7315

stock / discount

.4"

.001"

1.18"

.001"

> 1.5 N

7316S

179.00

Pipe dial thickness gage

 

Pipe gages have a spherical anvil (ø.14") and a flat upper contact designed for measuring the thickness of a tubular wall. It can also be used by musicians to measure the graduated thickness of double reeds for oboes and bassoons. The anvil can be inserted into the tube for a distance of .78" See page 184 for details.

Teclock dial thickness gage

 

Known in some circles as a thickness micrometer, this Teclock thickness gage is frequently sold with the SPI, Fowler and other names on the dial. These full-sized thickness gages have a lifting lever on top allowing for easy, one-handed operation. The large dial diameter is 2.16" and the flat measuring face (anvil) .394" in diameter, is ceramic. See measuring force below. Made in Japan. Spare parts will not be available making repairs impossible.

 

Teclock model SI-112 shown above, with the SPI name on the dial.


Some of these Teclock thickness gages are no longer available. The "Equivalent" column, below, will suggest suitable replacements found elsewhere on this page.

Range

Throat Depth

Resolution

Measuring force

SPI No.

Model no.

Equivalent

.500"

1"

.001"

2.5 N

24-360-0

SI-112

check internet discount

1.000"

4.75"

.001"

3.5 N

24-362-6

SI-530

Mitutoyo 7322S

10 mm

26 mm

0.01 mm

2.5 N

SM-112

Mitutoyo 7301

20 mm

30 mm

0.01 mm

3.5 N

SM-528

Mitutoyo 7305

Kafer dial thickness gage - pocket size

 

Kafer JZ15E (SPI Model 20-792-8) shown above with spherical anvils for hard, flat surfaces

 

Pocket-style but with a larger dial (1-9/16"). These offer three anvil styles for assorted applications. Measuring force, important because it can deform softer substances is approximately 0.7 Newton. Use the special 10 mm diameter flat anvils for deformable materials such as plastic film, fabric, leather and paper. The convex anvils are for plywood and other semi-hard materials. The ball anvils (shown in the photo above) are suitable for hard metal. The anvil is spring loaded and it's raised by turning the top roller. Shown here are the Käfer models, made in Germany with Old-World craftsmanship. (See information on thickness gages with 1.2" diameter anvils.)

 

Kafer Model J15 (SPI model 21-790-1) with 6 mm diameter flat anvils (above) can be used to measure hair thickness, for example.

Kafer Model JZ15C with larger 10 mm diameter flat anvils is suitable for softer, more compressible materials.

 

Order no.

Range

Throat Depth

Resolution

Style

Accuracy

2016 Price

JZ15

.400"

.700"

.001"

6 mm flat anvils

.0006"

225.00

JZ15C

.400"

.700"

.001"

10 mm flat anvils

.0006"

225.00

JZ45

.400"

1.77"

.001"

6 mm flat anvils

.0006"

278.00

JZ15D

.400"

.700"

.001"

3/8" Ø convex

*

225.00

JZ15E

.400"

.700"

.001"

spherical

*

225.00

J15

10 mm

17 mm

0,01 mm

6 mm flat anvils

15µ

225.00

J15C

10 mm

17 mm

0,01 mm

10 mm flat anvils

15µ

225.00

J15E

10 mm

17 mm

0,01 mm

spherical

*

225.00

 

* The accuracy for rounded and convex anvils is assumed to be similar to flat anvils, but according to the manufacturer there is no practical way for this to be verified near the zero point .

The force on these models of Kafer pocket thickness gages is approximately 0.7 N

  • Model J15 is equivalent to SPI 21-790-1.
  • Model J15C is equivalent to discontinued Mitutoyo 7309
  • Model JZ15C is equivalent to discontinued Mitutoyo 7308
  • Model J15E is equivalent to discontinued SPI 21-792-7
  • Model JZ15 is equivalent to SPI 20-790-2.
  • Model JZ15E is equivalent to discontinued SPI 20-792-8.
  • Model JZ15D is equivalent to SPI 20-791-0

     

Interchangeable anvils

 

Normally, contact points and anvils can not be replaced or interchanged on these gages. If they are flat surfaces, then they have been installed to lie parallel to each other. Replacing them removes any guarantee of accuracy.

If you do not need 2 flat surfaces for measuring, then you have an option of several different contacts and anvils on Mitutoyo model 7328S thickness gage. Please refer to page 216 for details.

 

How to measure the thickness of a sheet of paper

 

For a flat sheet of paper, use a thickness gage which has flat anvils, top and bottom such as model 7309 shown on this page. Before you take a measurement, clean the anvils with a bit of alcohol, then place a piece of clean paper between the anvils, let them rest together under their own force, then pull the paper out slowly. This polishes and further cleans the surface.

Now, with the paper removed, allow the gage to close. The hand (the pointer) will point to the twelve o'clock position, to zero. If the zero is slightly off, then you can rotate the bezel until the hand lines up with the zero, exactly. Now lift the anvil and repeat several times to make sure it always points to zero. This is called repeatability and should always be less than half a graduation.

Now lift the anvil and insert the paper. Let the anvil close down on the paper and slide the anvils a little bit so you find the lowest reading on the dial. At first, the readings will fluctuate a few graduations because you may not be working parallel with the surface. You'll eventually find the right spot where the hand no longer fluctuates. Take this reading (one line = .001" in most gages).

If the hand points to 31 then you have a thickness of 31 mils, or .031". If it points to 10 then the thickness is 10 mils or .010". Since the gage has an accuracy of ±.001" your reading is correctly stated as "10 mils plus or minus one mil." This, of course means that the actual thickness might be as little as 9 mils or as much as 11 mils. There is no way you can get around this fact. Now repeat the process with the same sample. Do this about 3 times to make sure you always get the same reading. If the readings are off, you're not holding or manipulating the gage correctly.

One more thing: a "mil" is not the same as a millimeter (mm). They are entirely different dimensions. If your gage is metric, and the graduations are 0.01 mm, then every ten graduations will equal 0.10 mm. The same principles outlined above will apply.

 

How to calibrate your thickness gauge

 

If the dial thickness gage has flat anvils, as most of them do, you will want to make sure they lie parallel when closed. Clean the anvils with alcohol as needed. The easy way to check this is to hold them up to a light and look for gaps. If there are no obvious gaps then set the dial to zero. At this point, insert a calibrated gage block between the anvils and check the dial reading several times. You should not be off by more than one graduation. If it is off, then make sure the block is lying flat and properly seated. Also make sure that the anvils—and the gage block—are very, very clean. It stands to reason that if the anvils are not parallel, you'll get a different reading on one side of the anvils. Use the gage block to test for this possibility.

If your thickness gage has a relatively short range, then one or two different size gage blocks should suffice for calibration. Choose one for the middle range and one for the far range. Of course, if you only use the thickness gage for some specific measurement, then choose a gage block with approximately the same dimension.

Starrett Dial Indicator Pocket Gage

 

Starrett1010RZStarrett1010EZ

Starrett Model 1010RZ (with round feelers) and Model 1010EZ with flat feelers

Starrett makes a series of pocket thickness gages which are surprisingly expensive when compared to other choices shown on this page. In this case, Starrett does not make a claim that they are American made.

Books by René Urs Meyer

The Companion Reference Book on Dial and Test Indicators … page 178
Repair Manual for Swiss-made BesTest and TesaTast Indicators … page 177
Starrett 711 Last Word Indicator Repair Manual … page 199
Interapid Indicator Repair Manual … page 208
 

www.longislandindicator.com

Long Island Indicator Service Inc
14 Sarah Drive — Hauppauge NY 11788 — USA


Contact us
Shopping CartSales TermsRepair ServiceHome

This page's most recent revision: 5 JULY 2016
All Rights Reserved

Original photographs and content copyright 2016 by JWGrum

glossyblack3dbuttoniconsocialmedialogosfacebooklogo2

Interested in metrology? Join our group on Facebook by clicking on the link above.