What are the grades of granite surface plates?
Manufacturers use three standard grades of flatness defined by the federal specification: Laboratory grade AA: (40 + diagonal [in inches] of surface plate squared/25) x 0.000001 in. Inspection grade A: Laboratory Grade AA x 2. Tool room grade B: Laboratory Grade AA x 4.
What are granite surface plates used for?
Granite Surface Plate – Overview JASH Granite Surface Plates are used for precision gauging, inspection, layout and marking purposes. They are preferred by Precision Tool Rooms, Engineering Industries and Research Laboratories because of their following outstanding advantages.
How much does a granite surface plate weigh?
Starrett Pink Granite Surface Plate, 48″ x 72″ Grade A Inspection – 80758
| Item Number | Description | Weight: |
|---|---|---|
| 80758 | Pink Granite Surface Plate | 3300 lbs. |
Is standard for granite surface plate?
This Indian Standard ( Second Revision ) which is identical with ISO 8512-2:1990 ‘Surface plates — Part 2: Granite’ issued by the International Organization for Standardization ( ISO ) was adopted by the Bureau of Indian Standards on the recommendations ofthe Engineering Metrology Sectional Committee and approval of …
Which surface plate is more accurate?
Granite is considered to be the best material for a surface plate due to its surface hardness, low thermal expansion, no rust or corrosion, little warping, and long wear life attributes. These attributes result in very accurate, stable and precise measurements.
Why granite is the most popular material for surface plates?
Granite surface plates are best known due to their rustless properties. Granite surface plates remain unaffected by the change in temperature and Heat as well so hence it can maintain the flatness for a longer period of time. The hardness of the granite surface plates is more than the C.
How do you calibrate a granite surface plate?
Pour a small amount of surface plate cleaner on a clean, soft cloth and wipe the surface of the granite. Immediately dry the cleaner off the surface plate with a dry cloth. Do not allow the cleaning liquid to air-dry. Place a repeat measuring gauge on the center of the granite surface plate.
What are surface plate grades?
There are varying grades used to describe the accuracy of some metrology equipment such as: AA, A, B, and Workshop grade. While workshop grade is the least accurate, all grades of surface plates are held to a high degree of flatness. Tools and workpieces may also cause damage when dropped on the surface plate.
What is a grade 0 surface plate?
The surface plate is often used as the baseline for all measurements to a workpiece, therefore one primary surface is finished extremely flat with tolerances below 11.5 μm or 0.0115 mm per 2960 mm for a grade 0 plate.
What is the accuracy of surface plate?
They have been proven very valuable to record long term effects of surface plates. Reliable measurements with an accuracy of 0.1 μm/m demonstrate the capabilities of the method.
Why is granite the most suitable material used for surface plates?