Granite surface plates are used for precision gauging and inspection due to their exceptional flatness and stability. Some of the key features of granite surface plates are as follows: - Flatness: Granite surface plates are very flat, with variations in flatness typically less than 0.0001 inches per linear foot. This makes them ideal for setting up and verifying the flatness of other surfaces and for measuring small features with high accuracy. - Stability: Granite is an extremely stable material, meaning it will not warp or deform under normal working conditions. This makes granite surface plates the preferred choice in many applications where precise measurements are critical. - Hardness: Granite is a hard material, twice as hard as cast iron , which minimizes changes in dimension due to temperature changes . This ensures that measurements taken on a granite surface plate will remain accurate even under varying temperature conditions. - Wear resistance: Granite is highly resistant to wear and damage, making it a durable choice for surface plates. With proper care and maintenance, granite surface plates can last for many years. - Absence of wringing: Because granite is not prone to "wringing" (the tendency for two surfaces to stick together due to friction), granite surface plates provide a stable and reliable surface for precise measurements. Overall, the natural properties of granite make it an ideal material for use in precision measurement applications, and the features discussed above make granite surface plates one of the best choices for such applications. MakePink Granite Surface Plate Model Year1995 or older Product #09720 Price Please login to see price. Make an Offer Get a Quote Share Ask a Question About This Machine . Live Tooling / Milling Specifications Spindle Second Spindle Tool Changer Turret Control Tailstock / Steadyrest Options Product Description: Stand