Granite Surface Plates & Tables
BS 817:2008 | 120+ Years Expertise | British Manufactured
With over 120 years of material experience, Eley Metrology by Crown Windley specialise in the British manufacturing and resurfacing of granite surface plates and tables, conforming to BS 817:2008 with the option of UKAS certification.
Why Choose Eley’s Granite Surface Plates?
- Carefully Sourced Granite: Our 100% natural black granite is sourced from carefully selected quarries to ensure consistent material quality, extreme hardness, wear resistance and uniform structure.
- Thickness & Load Bearing Strength (Market Leading):
Our largest granite surface plates boast 250mm thickness, reducing deflection and providing higher load-bearing strength for massive components without distortion, maintaining flatness where thinner plates fail. - Hand-Lapped Black Granite: Built on 120+ years of knowledge, we deliver exceptional flatness (Grades 0, 1, and 2) through diamond abrasives and perfected hand-lapping techniques. Producing a superior surface finish vs. machine-ground.
- Low Co-efficient of Thermal Expansion: Offering approximately half the co-efficient of expansion as that of iron, our natural granite surface plates are carefully sourced and manufactured to ensure consistent measurements across workshop and laboratory temperature variations.
- Material Durability: Our natural black granite surface plates are built to last, withstanding decades of industrial use without degradation – outlasting cast iron 3:1.
- Precision Inspection and Calibration: Verify flatness, establish a traceable reference plane, and support height-gauge and CMM setups.
- Workshop and Laboratory Environments: Trusted by industries for over a century, our granite's low thermal expansion ensures consistent measurements, in both workshops and laboratories (although we highly recommend a temperature-controlled environment).
- Multi-Industry Usage: Our granite surface plates provide micron-level flatness for high-accuracy dimensional inspection needed in critical industries such as aerospace, automotive, defence, medical and more.
- Non-Magnetic Measurement Tasks: Ideal for measuring magnetic components or using digital height gauges without interference.
- Heavy Component Inspection: Our thicker granite surface plates reduce deflection under load, improving inspection accuracy for large assemblies where thinner plates typically suffer.
UKAS Certification: For immediate use, we offer UKAS certification or an Eley Metrology certificate of calibration, guaranteeing your surfaces are traceable to BS 817:2008 and inspection compliant upon arrival.
Granite Surface Plates to BS 817:2008 Standard Sizes & Flatness
|
|
GRADE 0 (µm)
|
GRADE 1 (µm)
|
GRADE 2 (µm)
|
WEIGHT (kg)
|
|---|---|---|---|---|
|
LOCAL VARIATION (µm)
|
3
|
6
|
12
|
|
|
SIZE (mm)
|
|
|
|
|
|
300 x 200 x 50
|
3.5
|
7
|
14
|
10
|
|
300 x 300 x 50
|
4
|
8
|
16
|
14
|
|
450 x 300 x 75
|
4
|
8
|
16
|
32
|
|
450 x 450 x 75
|
4.5
|
9
|
18
|
48
|
|
600 x 450 x 75
|
4.5
|
9
|
18
|
64
|
|
600 x 600 x 75
|
5
|
10
|
20
|
85
|
|
900 x 600 x 100
|
5.5
|
11
|
22
|
230
|
|
1000 x 1000 x 150
|
6
|
12
|
24
|
470
|
|
1200 x 900 x 150
|
6.5
|
13
|
26
|
582
|
|
1500 x 1000 x 200
|
7.5
|
15
|
30
|
716
|
|
1800 x 900 x 200
|
8
|
16
|
32
|
845
|
|
2000 x 1200 x 200
|
8
|
16
|
32
|
1150
|
|
2400 x 1200 x 250
|
9.5
|
19
|
38
|
1900
|
Eley Surface Plates
Manufactured using the same high-quality black granite, Eley Surface Plates offers another view into our smaller range of available granite surface plates.
Related Measurement Solutions
Digital Height Gauges
Pair your granite surface table with Eley Metrology’s technologically advanced digital height gauges to create a complete reference station.
surface plate Calibration & Resurfacing
Schedule free surface plate calibration and resurfacing to keep your granite surface plates within their specified tolerances.
FAQs
Do you manufacture bespoke granite surface tables?
Yes. We produce one-off and custom-sized granite surface tables and plates to your exact specifications. Whether you need non-standard dimensions, fixture slots, or specific grade tolerances, our team can advise on design and manufacturing options.
Speak to one of our specialists to discuss your requirements and raise a quote.
Email: sales@eleymet.com
Phone: 01332 367475
Do you provide on‑site granite surface table calibration and resurfacing?
Yes, we offer free on‑site calibration and resurfacing for granite surface tables and plates to help minimise downtime (see the terms of our offer) also offering UKAS calibration certification to BS 817:2008. We also provide in-house calibration and resurfacing within our temperature‑controlled facility in Derby.
Request a quote today.
Do you offer support stands for granite surface plates?
Our larger granite surface plates (900mm x 600mm x 100mm 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 600mm and above size plates when you require a specific working height.
What are all the advantages of granite surface plates?
A granite surface plate is an essential investment for laboratories and test facilities. A granite surface plate of 600mm x 600mm can be mounted on a support stand to create a granite surface table. 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
Granite vs cast iron which is better?
Granite surface plates succeeded cast iron surface plates over half a century ago and continues to hold its position as the most reliable, trustworthy and efficient material to be used as a datum. Granite surface plates offer lower thermal expansion, corrosion resistance, excellent vibration damping, and much more, making it ideal for stable, traceable measurement; cast iron can be preferable where heavy impact resistance is essential or you require a magnetic surface.
Contact us for a quote or to discuss calibration and maintenance packages for your granite surface tables.
Email: sales@eleymet.com
Phone: 01332 367475
Why choose granite?
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 table.
Eley Metrology produces bespoke granite artefacts that are created to support unique and 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.
Should I store my granite surface plate in a particular environment?
Yes, a controlled environment of 20±1°C and humidity 58±2%.
Keeping granite surface tables and plates in a consistently stable environment heavily reduces the chance of flatness/measurement errors – often referred to as ‘soaking’. As a key, remember to avoid any direct sunlight hitting the granite surface plate, as well as air conditioning units operating within close proximity as these can often affect its conditions and measurement results.
My granite surface plate is damaged - can this be repaired?
Yes. We offer granite surface plate repair and restoration as part of our services. Depending on the size and location of the damage/dent, our specialists can resurface and restore the plate to specification, often saving the cost of replacement.
Contact us to arrange an inspection and assessment.
Email: sales@eleymet.com
Phone: 01332 367475
How do I look after a granite surface plate?
Granite surface plates are highly resistant to wear and are fairly straightforward to maintain:
- Clean regularly with specialist granite cleaning fluid to remove dust, oils and debris that can affect measurement accuracy.
- Distribute wear evenly by rotating the use of different areas across the granite surface plate to extend its working life.
- Resurface as required — depending on use and care, periodic resurfacing restores original flatness and maintains UKAS traceability.
- Schedule routine calibration — regular UKAS calibration ensures the plate remains inspection-ready and meets your quality standards.
Eley Metrology offers onsite calibration and resurfacing service contracts to minimise downtime and guaranteeing you are on schedule to meet quality assessments and production. Our skilled engineers can assess your granite equipment at regular intervals and maintain it to optimum accuracy.
Contact us for a quote or to discuss calibration and maintenance packages.
Email: sales@eleymet.com
Phone: 01332 367475