FAQ

Question 1

Why Choose Granite?

Accepted Answer

Granite is a type of igneous rock formed in the Earth millions of years ago. The composition of igneous rock contains many minerals, such as quartz which is extremely hard and wear-resistant. In addition to hardness and wear resistance, granite has approximately half the coefficient of expansion as cast iron. As its volumetric weight is approximately one-third that of cast iron, granite is easier to manoeuvre.

For machine bases and metrology components, black granite is the colour most used. Black granite has a higher percentage of quartz than other colours and is, therefore, the hardest wearing.

Granite is cost-effective, and cut surfaces can be exceptionally flat. Not only can it be hand-lapped to achieve extremes of accuracy, but re-conditioning can be performed without moving the plate or table off-site. It is entirely a hand-lapping operation and generally costs much less than re-conditioning a cast iron alternative.

These qualities make granite the ideal material for creating custom-size and custom-design machine bases and metrology components such as the granite surface plate.

Eley Metrology produces bespoke granite products that are created to support specific measurement requirements. These bespoke items vary from straight edges to tri squares. Due to the versatile nature of granite, the components can be produced in any size required; they are hard-wearing and long-lasting.

Question 2

What are the Advantages of Granite Surface Plates?

Accepted Answer

A granite surface plate is an essential investment for laboratories and test facilities. A granite surface plate of 600 x 600 mm can be mounted on a support stand. The stands provide a working height of 34” (0.86m) with five adjustable points for levelling.

For reliable and consistent measurement results, a granite surface plate is crucial. As the surface is a smooth and stable plane, it enables instruments to be carefully manipulated. They are also used in set-up of tooling, production and inspection.

The main advantages of granite surface plates are:

Non-reflective
Resistant to chemicals and corrosion
Low coefficient of expansion compared with cart iron, so less affected by temperature changes
Naturally rigid and hard-wearing
The plane of the surface is unaffected if scratched
Will not rust
Non-magnetic
Easy to clean and maintain
Calibration and resurfacing can be done onsite
Suitable for drilling for threaded support inserts
High vibration damping

Question 3

How Do You Look After Granite Surface Plates?

Accepted Answer

Due to being highly resistant to wear, granite surface plates are easy to maintain. With regular cleaning using a specialist granite cleaning fluid, the surface plates can remain reliable. We recommend that you use different areas of the granite surface to distribute the workload evenly.

Depending on the care and use of the surface plate, resurfacing will be required at some point. Granite surface plate calibration and resurfacing are vital to maintain original accuracy. Granite surface plates can be re-conditioned onsite with a quick turnaround to minimise disruption and downtime.

Eley Metrology can arrange an inspection of your granite equipment at regular intervals. Our team of highly skilled engineers can ensure that your granite equipment is maintained to optimum accuracy and quality levels.

Please get in touch if you would like a quote or more information on our granite surface plate inspection and maintenance packages.

Question 4

What Grades Are Available?

Accepted Answer

Our granite surface plates are available in three grades: Grade 0, Grade 1 and Grade 2.

Question 5

Do Eley Metrology Provide a UKAS Certificate of Calibration?

Accepted Answer

All our granite plates and tables are supported by a UKAS Certificate of Calibration and conform to BS 817 (2008).

Question 6

Do You Offer Support Stands?

Accepted Answer

Our larger surface plates (900 x 600 x 100 and up) are available with a high-quality steel support stand with three adjustable points to ensure flatness on any surface. Support stands can also be applied to the 600 and above size plates when you require a specific working height.

Question 7

Can You Create Bespoke Sized Plates?

Accepted Answer

We can produce one-off or bespoke-sized granite surface plates to your specifications. Please contact our team to discuss your requirements.

Question 8

Do You Offer Granite Surface Plate Calibration?

Accepted Answer

Our team of engineers provide calibration and resurfacing for all sizes and grades of granite surface plates and tables. We can also calibrate granite parallels, master squares and master straight edges.

Our highly skilled team will hand-lap your granite back to the original specification in accordance with BS817 (2008) supported by a UKAS certificate of calibration.

Granite Surface Plates

Bespoke Sizes Available

Adjustable Support Stands