CMM Styli and Accessories Technical Data
Technical data is supplied to assist you in understanding our products. If
you require additional information please call us at (528) 759-2400 or send
us an email.
Stylus Anatomy 101
 |
Call Out |
Description |
| dk |
Ball diameter |
| ds |
Shank diameter |
| D |
Ferrule diameter |
| L |
Overall length |
| ML |
Working length |
| M |
Thread |
| Wt. |
Approximate weight, in grams |
| Drawings are not to scale. Consult charts for actual dimensions |
Ball and Shank Assembly
Pivot Mount: A drilled ruby is glued to the reduced tip end
of the the pivot at shank end.
Solid Ball Mount: An undrilled ruby is glued directly to the
end of the shank
- 0.4mm and smaller diameter balls cannot be drilled for pivot.
- Drilled ball / pivot mount designs are recommended for 0.5mm and
larger diameters for long life and durability
Advantages of Shank Materials:
Carbide:
- Sub-mircon deflection
- Small diameters
- Non-magnetic
|
Stainless Steel:
- Durable
- Lowest cost
- Wide-spread acceptance
|
Ceramic
- Zero deflection
- Light weight
- Easy to see
- Same Coefficient of Thermal Expansion as ball
- Non-magnetic
|
Carbon Fiber:
- Great for high speed machines
- Light weight minimizes false triggering
- Use for long stylus configurations
- Non-magnetic
|
Sapphire:
- Light weight
- Maximum strength
- Highest accuracy
- Same Coefficient of Thermal Expansion as ball
|
|
| Technical Data |
| Item |
Material |
Form Deviation |
Diameter Tolerance |
Hardness(Vickers) |
Density(g/cm3) |
Surface Finish |
| Ruby ball |
Synthetic ruby AI203 monocrystalline |
<0.2µ |
±0.25µ |
1800 |
3.9 |
0.015µ |
| Hollow ceramic balls |
Alumina, AI2O3 ceramic polycrytalline |
<0.6µ |
±0.6µ |
1650 |
3.9 |
0.1µ |
| Cylinder |
Stainless steel |
<2µ |
±10µ |
250 |
7.9 |
0.4µ |
| Cylinder |
Synthetic ruby AI2O3 monocrystalline |
<1µ |
±1µ |
1800 |
3.9 |
0.5µ |
| Cylinder |
Tungsten carbide |
<1µ |
±1µ |
1550 |
15.0 |
0.2µ |
| Ball disc, ceramic |
Ceramic, alumina AI2O3 ceramic polycrystalline |
<0.6µ |
±0.6µ |
1650 |
3.9 |
0.1µ |
| Ball disc, steel |
Stainless steel |
<3µ |
±10µ |
250 |
7.9 |
0.4µ |
| Ball disc, steel |
Hardened steel |
<2µ |
±10µ |
720 |
7.9 |
0.2µ |
| Shank or Extension |
Stainless steel |
- |
- |
- |
7.9 |
- |
| Shank or Extension |
Ceramic, alumina AI2O3 ceramic polycrystalline |
- |
- |
- |
3.9 |
- |
| Shank or Extension |
Carbon fiber |
- |
- |
- |
1.5 |
- |
| Shank |
Tungsten carbide |
- |
- |
- |
15.0 |
- |
| Extension |
7075 high strength aluminum |
Hard coat anodized surface with PTFE
inserts |
2.8 |
- |
Grade Tolerances ChartA.F.B.M.A. Standards
| A.F.B.M.A. Grade |
Diameter Tolerance per Ball Sphericity |
Diameter Tolerance per Unit Container |
Basic Diameter Tolerance |
Marking Increment |
|
Inch |
Inch |
Inch |
Inch |
| 3 |
.000003 |
.000005 |
±.00003 |
.000003 |
| 5 |
.000005 |
.00001 |
±.00005 |
.000005 |
| 10 |
.000010 |
.00002 |
±.0001 |
.000010 |
| 15 |
.000015 |
.00003 |
±.0001 |
.000015 |
| 25 |
.000025 |
.00005 |
±.0001 |
.000025 |
| 50 |
.00005 |
.0001 |
±.0002 |
.00005 |
| 100 |
.0001 |
.0002 |
±.0005 |
.0001 |
| 200 |
.0002 |
.0004 |
±.0010 |
.0002 |
Definitions:
- Grade: The numerical value of the diameter Tolerance per Ball
expressed in millionths of an inch.
- Diameter Tolerance per Ball Sphericity: The permissible difference
between the largest diameter and the smallest diameter measurable on one ball
- Diameter Tolerance per Unit Container: The permissible range on
the average diameters of the individual balls within any one container
- Basic Diameter: The size ordered which is the basis to which the
basic diameter tolerances apply. The Basic Diameter is specified by a
fraction plus a decimal, or a decimal only, to the sixth place, e.g. 1/4"+
.0002" or .2502" or 15/64"+.0003" or .234675".
- Basic Diameter Tolerance: The maximum allowable deviation of any
ball diameter from the basic diameter, in any shipment to fill orders for
that basic diameter
- Marking Increments: The standard unit steps in millionths of an
inch used to express the specific diameter
