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 Brown & Sharpe (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, 18.60202 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. Contact points are generally in stock. Larger orders may, however, require 2-3 weeks.