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BesTest Test Indicator Contact Points
Tesatast Contact Points

Carbide, Ruby, Nylon and Teflon contact points for the Swiss made Bestest and Tesatast test indicators

We also have contact points for the following indicators:

  • Compac M1.6 carbide and ruby test indicator contact points … page 205
  • Interapid M1.7 carbide, ruby and Teflon contact points … page 21
  • Mitutoyo M1.7 test indicator contact points … page 186
  • Starrett test indicator contact points … page 239
  • contact points for dial indicators

Related topics

  • Bestest indicator specifications … page 4
  • Bestest indicator repair manual … page 117
  • Tesatast contact points … see below
  • Cosine error: How to compensate … see below
  • Ruby, Teflon and Nylon points avoid scratching surfaces, are non-conductive … see below
     

Bestest M1.4

 

The model suffix (-3 and -5) refers only to whether the dial is white or black. For example 7030-3 and 7030-5. Older, obsolete models had -2 or -1 as a suffix. They also use the same contact points. Points are identical for inch and metric models. Thread size is M1.4 (outside diameter is about 1.4 mm).

You can also buy a special double length point which is 1" long (28 mm from shoulder to center of ball). When installed, the readings on the dial will be doubled. In other words, the .0005" indicator will now read .001". Make sure you label your indicator when you do this, so that no one misreads the dial.

How are they measured? From the shoulder (not including the thread) to the center of the ball. Custom ball diameters are available as well as teflon and nylon. Bestest contact points can be used with the Adapt-A-Tip adapter (shown on page 133) for dial and digital indicators.

Why are there multiple ordering numbers? The points are the same but the B&S numbers are used in the USA, while the TESA numbers are for the rest of the world, while MTC is a numbering system we use. You may also encounter variations on the TESA numbers, such as 018602-00 or 01860202. (Notice that this merely eliminates the decimal point and adds a leading zero.)

.080" carbide points are standard and are installed on all new BesTest indicators.

Model*

Length

Ball Diameter

Price

Our Ordering Number

Manufacturer Equivalents

7021-3
7022-3
7023-3
7024-3
7029-3
7030-3
7031-3
7032-3
7033-3
7037-3
7038-3

7029-5
7030-5
7031-5
7032-5
7033-5

7033-13

.5"
(12.5 mm)
(1/2")

carbide Ø .015"

$21.50

MTC21-07
order now

599-7030-15
and/or
Tesa 18.60200

carbide Ø .040"

$19.50

MTC21-08
order now

599-7030-40
and/or
Tesa 18.60201

carbide Ø .080"

$19.50

MTC21-10
order now

599-7030-80
and/or
Tesa 18.60202

carbide Ø .120"

$19.50

MTC21-12
order now

599-7030-120
and/or
Tesa 18.60203

for all the above
(optional)


double length

1.1"
(28 mm)
see notes

carbide Ø .030"

$21.50

MTC21-34
order now

 

carbide Ø .080"

$21.50

MTC21-37
order now

 

Model*

Length

Ball Diameter

Price

Our Ordering Number

Manufacturer Equivalents

7034-3
7035-3

7034-5
7035-5

1.436"
(37 mm)
(1-7/16")

carbide Ø .015"

$21.50

MTC22-02
order now

Tesa 18.60210

carbide Ø .040"

$19.50

MTC22-04
order now

599-7034-40
and/or
Tesa 18.60211

carbide Ø .060"

$19.50

MTC22-05
order now

Tesa 18.60216

carbide Ø .080"

$19.50

MTC22-06
order now

599-7034-80
and/or
Tesa 18.60212

carbide Ø .120"

$19.50

MTC22-08
order now

599-7034-120
and/or
Tesa 18.60213

for all B&S
Bestest

contact point wrench

$7.30

B&S 97-45

Tesa 18.60307

 

* these numbers are valid for all -1, -2, -3, -13 and -5 models such as 7030-13, 7035-5 and 7032-3, etc.



 

Ruby, Nylon and Teflon points

 

These contact points are used for special applications, typically in optics. The ruby point outlasts standard chrome points and does not expand or contract with heat and cold. It does not conduct an electric current so it can be used on your machines without creating interference. It is also less likely to scratch delicate surfaces. It's also the material that will hold up to silicon carbide surfaces. The Teflon point is softest made of a solid Teflon ball. It is very white in appearance. It is least likely to scratch but is not as long lasting as the others. The smallest Teflon diameter available is 1/16" (.062"). Smaller points can not be manufactured in this material. The Nylon point is not as soft as Teflon but will last longer. It can also be used where surface damage is an issue. Nylon appears opaque.

If you buy any new test indicator from us, you may request one of these points to replace the standard carbide point. A fee applies to make up the difference in cost.

 

Model*

Length

Ball Diameter

Price

Our Ordering Number

Manufacturer Equivalent

7021-3
7022-3
7023-3
7024-3
7029-3
7030-3
7031-3
7032-3
7033-3
7037-3
7038-3
7029-5
7030-5
7031-5
7032-5
7033-5
7033-13

.5"
(12.5 mm)
(1/2")

ruby Ø .040"

$29.50

MTC21-18
order now

Tesa 18.60205

ruby Ø .080"

$29.50

MTC21-19
order now

Tesa 18.60206

7034-3
7035-3
7034-5
7035-5

1.436"
(37 mm)
(1-7/16")

ruby Ø .040"

$29.50

MTC22-15
order now

ruby Ø .080"

$29.50

MTC22-16
order now

ruby Ø .100"

$29.50

MTC22-17
order now

for all B&S
Bestest

contact point wrench

$7.30

B&S 97-45

Tesa 18.60307

 

* these numbers are valid for all -1, -2, -3, -13 and -5 models such as 7030-13, 7035-5 and 7032-3, etc.



 

Model*

Length

Ball Diameter

Price

Our Ordering Number

Manufacturer Equivalent

7021-3
7022-3
7023-3
7024-3
7029-3
7030-3
7031-3
7032-3
7033-3
7037-3
7038-3
7029-5
7030-5
7031-5
7032-5
7033-5
7033-13

.5"
(12.5 mm)
(1/2")

Teflon Ø .060"

$29.50

MTC21-22
order now

 

Teflon Ø .080"

$29.50

MTC21-23
order now

 

7034-3
7035-3
7034-5
7035-5

1.436"
(37 mm)
(1-7/16")

Teflon Ø .060"

$29.50

MTC22-19
order now

 

Model*

Length

Ball Diameter

Price

Our Ordering Number

Manufacturer Equivalent

7021-3
7022-3
7023-3
7024-3
7029-3
7030-3
7031-3
7032-3
7033-3
7037-3
7038-3
7029-5
7030-5
7031-5
7032-5
7033-5
7033-13

.5"
(12.5 mm)
(1/2")

Nylon Ø .060"

$29.50

MTC21-25
order now

 

Which contact point to choose?

 

 

Contact points are always available from Long Island Indicator Service. There are four components to take into consideration.

  • ball diameter
  • thread diameter
  • contact point length
  • ball composition

New indicators come supplied with .080" diameter balls as standard. We list the most common sizes below, but for special needs other diameters are often available. Thread diameters vary from manufacturer to manufacturer but are generally metric threads. Manufacturers differ in their method of measuring contact point lengths. It is imperative that the correct length point is used. Refer to the charts below for details on how the length is determined.

What are the contact points made of?

Our contact points are turned from #303 stainless steel and have carbide, ruby, Nylon or Teflon balls.

  • "Alloy 303 is a non-magnetic, austenitic stainless steel that is not hardenable by heat treatment. It is the free machining modification of the basic 18% chromium / 8% nickel stainless steel." [source: pennstainless.com/stainless grades]
  • austenite = a solid solution of carbon in a nonmagnetic form of iron, stable at high temperatures. It is a constituent of some forms of steel. [Oxford English Dictionary]

We recommend carbide balls over chrome or steel for its durability. For special applications you may need the ruby, sapphire, teflon, nylon or some other exotic. Please email special requests.

The contact points listed here are home grown. They're every bit as good as the originals yet they cost less. We give you the manufacturer's ordering number for ease of reference. If you'd rather have the manufacturer's own contact points please send us a request for quotation.

How to install a contact point

Most test indicators come with a little wrench of some sort designed to help you tighten—or loosen—a contact point. Some points have a little hole drilled through them so that you can insert a pin which can then be used to twist the point. Others have two flat spots designed to work with the wrenches supplied. Still others have a hexagonal area which works very well with a pair or small pliers. In all cases, small pliers can be used to remove and tighten contact points. Make sure they are nice and snug, hand tightened only. You don't want to force any contact point that refuses to co-operate. Try another point instead. The thread may be damaged, or you may be using a point with the wrong thread. If the thread breaks off inside the indicator, you may have a hard time getting it out and a repair might then be in order.

needlenosepliers
Xcelite L4G Sub-Miniature Needle Nose Plier with Green Cushion Grip Handle, Smooth Jaw, 4" Length, 13/16" Jaw Length
 

Longer contact points

 

You may wish to substitute a long contact point on short point models. If the point is exactly twice the length then the readings on the dial will be doubled. A .0001" indicator will now read .0002" and a .0005" indicator will now read .001".

The indicators were not designed with these long points in mind and you may see some problems with repeatability and hysteresis because these long points weigh more. The extra weight interferes with the hair spring and return spring and that may be noticeable in .0001" models.

Once this long point is installed, be sure to label the indicator with the new readings so no one else will make mistakes. These double lengths can be custom made for most models, although some are in stock (see charts below).

 

Federal

 

The discontinued Federal Series 100 indicators (T-101, T-102, etc.) were manufactured by Tesa in Switzerland. The contact points are identical to those used by the Brown & Sharpe Bestest indicators.

Old style points (M-1, T-1, etc.) had ratchets rather than threads. They are no longer available from us.
 

Tesatast and SwissTast

 

Points are identical for inch and metric models. For that matter, these points are identical to Bestest points. You can order any of the Bestest points on this page but be sure to order the correct length as shown below.

Tesa model

Contact point length

18.10005
18.10006
18.10009
18.10010
18.10013
18.10204
18.10304
18.11001
18.20006
18.20007
18.20010
18.20011
18.20012
18.20013
18.20014
18.20015
18.20204
18.20304

.5" (12.5 mm)

18.10007
18.10008
18.10012
18.10205
18.20008
18.20009
18.20016
18.20205

1.436" (37 mm)

Cosine error

 

We know that the length of the contact point determines the ratio of leverage. In order to get accurate dial readings the length must be as specified by the manufacturer.

Changing the angle of the contact point changes the ratio just as if you had installed a somewhat shorter point. As a result, the readings on the dial will be higher than they should be.

To compensate for this cosine error it will be necessary to multiply the reading on the dial by the cosine of the angle between the contact point and the measuring surface.

How do you measure the angle? Most of us can intuitively judge an angle of 45° and, perhaps with a little less accuracy, an angle of 30°. Beyond that, we need help. A simple protractor like we used in grade school will suffice. Lay the straight edge on the measuring surface and, by eye, make a judgement of the angle. A few degrees one way or another won't be significant.

Where do you find the cosine? Use a scientific calculator or a printed chart.

calculatorimage1
Texas Instruments Scientific Calculator

Enter the value of the angle: for 20° enter "20" and press the COS (cosine) button. The display will read .9340 (allowing for rounding up).

Now it's simply a matter of multiplying the reading on your test indicator with this value.

For example: when the reading is .0006" you multiply .0006" x .9340 and the result is .00056"

This is just as expected. Your reading of .0006" was larger by .00004" than it should have been.

From this example you can see that angles of 20 degrees or less have relatively insignificant effects on the reading. But, when the angles are larger you'll be wise to make cosine error adjustments.

This same cosine error applies to all makes of test indicators regardless of contact point lengths and resolutions. Some Fowler test indicators feature "pear-shaped" contact points which compensate, in theory, for the cosine error. These may be a good choice if you frequently use a variety of measuring angles.

Interapid indicators pose a special problem. They're designed to work without cosine error at 12°. When setting up, use a protractor to make sure you're in the ball park. If you're off, then you'll have to compensate, just like the others. If the angle is 32° then the cosine will have to be of the difference between 32° and 12°, in other words 20°. Make the calculations as above.

 

Q&A

 

Q: Our .0001" Bestest indicator is a half-graduation under at the mid-point and a whole graduation under when once around. What is wrong?

  • This and other indicator related questions are now answered in our new publication (see top of page).
     

Q: We lost the contact point wrench that came with the indicator. Can I just unscrew it?

  • You can safely use needle nose pliers for this purpose. The short jeweler's type is ideal.


TEKTON 3506 4-1/2-Inch Precision Long Nose Pliers

 



 

 

LONG ISLAND INDICATOR REPAIR MANUALS

BesTest and TesaTast Indicator Repair Manual … page 177
Starrett 711 Last Word Indicator Repair Manual … page 199
Interapid Indicator Repair Manual … page 208
Compac Test Indicator Repair Manual … page 194
Mitutoyo Test Indicator Repair Manual … page 102
 

www.longislandindicator.com

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


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This page's most recent revision: 25 JULY 2017
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Original photographs and content copyright 2017 by JWGrum

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