On typical API thread grinding or profile grinding wheel cores which are CNC
turned in diameters up to 20" and coated with 325/400 Mesh (FEPA D46), which are
clocked or indicated to within .0005" (0.012mm, the minimum achievable ground part tolerances are:
- Radii +/-.0007" (0.018mm)
- Tooth or form location +/-.0005" (0.012mm)
- Maximum run out in X and Y axis .0005" (0.012mm)
Refer to the DIANAMIC superabrasive particle size reference chart for a
complete listing of achievable tolerances by mesh / micron size.
|
Minimum Achievable Radii by Mesh Size |
|
Mesh |
Female |
Male |
|
400/500 |
.003" |
.003" |
|
325/400 |
.004" |
.005" |
|
270/325 |
.005" |
.006" |
|
230/270 |
.006" |
.008" |
|
200/230 |
.008" |
.010" |
|
170/200 |
.010" |
.012" |
|
140/170 |
.011" |
.013" |
|
120/140 |
.012" |
.015" |
|
100/120 |
.015" |
.015" |
|
80/100 |
.018" |
.018" |
|
60/80 |
.020" |
.025" |
|
40/50 |
.035" |
.035" |
API Thread Grinding Technical Information
Wheel Size
The most common API Thread Grinding Wheel offering the greatest accuracy is either 7" (178mm) or 6" (152mm)
- Ground forms up to 10" Diameter x 10" Width
- CNC turned forms up to 20" Diameter x 12" Width
Angular Compensation
For each design or part number, a 20X and 50X Mylar is created. The mylar is compensated to achieve the ground profile required. We compensate the form according the individual prints specifications for:
- Front, Side and Radial clearance
- Helix Angle
- Top Rake
- Tilt
Compensations with more than one correction are quite common. To achieve the correct
profile we will advise if any special fixturing or angular tilting is required.
Angular tilting of sharp angles dramatically increase wheel life.
Profile Limitations
We are limited by the size of the Diamond or cBN Mesh size specified in respect
to profile limitations. The tabulated chart indicates the minimum Female and
Male radii achievable in the ground profile.
Inspection Mylars or Comparator Overlays
Our engineering department can provide part mylars for inspection in the following powers:
- 10X
- 20X
- 32.5X
- 50X
- 100X
The inspection mylars can be of compensated forms or forms checked square.
Mylars with the full form at 20X and single tooth at 50X is a very common option.
If your optical comparator is 14" or smaller we can offer a mylar with teeth tabulated
with exact moves which will fit your screen. Normal cost is $125.00 per drawing.
Delivery
Normal delivery is 2-3 weeks from receipt of print. Strip / recoat delivery is
5 - 7 days from receipt of wheel blanks. Strip / remachine / recoat delivery is 7-10 days.
Emergency delivery on new is 3-5 days from receipt of order and print at a 50% surcharge.