any suggestions on selecting a surface plate?

Any Suggestions on Selecting a Surface Plate?

The Shars surface plate features two ledges, which can be incredibly useful for securely clamping items to the plate. While Chinese surface plates often boast respectable accuracy claims, it's important to note that these claims can be misleading due to a lack of robust quality control and assurance programs. Generally, they can serve shop work adequately, unless perhaps you acquire one manufactured at the end of a production shift. The pricing of these plates is attractive, often less than half the cost of comparable US-made options. However, determining if you've received a high-quality plate can be tricky, as thorough testing isn't typically feasible in most hobbyist settings, rendering the grading system quite ambiguous. If absolute certainty in quality is required, considering suppliers like Standridge Granite is sensible, but be prepared for a significantly higher price point for assurance in your purchase.

I personally own a Woodcraft surface plate, and I resonate with Bob’s sentiments regarding its accuracy. Included with the plate is a surface map, which while helpful, doesn’t guarantee precision beyond a grade A designation, making it suitable for use on the shop floor. My decision to purchase this over a certified plate was largely influenced by the exorbitant shipping costs to Hawaii for a certified option. So for now, this will have to suffice—I wouldn't turn down a Standridge plate, though (hint, hint).

One useful technique for evaluating the accuracy of a surface plate is to scrape a straight edge against it, subsequently using that straight edge to assess how flat the plate is. This method, which Connelly elaborates on in his Machine Tool Reconditioning book, is somewhat self-verifying: after scraping the edge flat, you can rotate it and check the bluing pattern. If the pattern remains consistent upon rotation, the plate is likely flat; if not, there's an issue. It's worth noting that while this method provides some insights into flatness, it doesn't reveal specific discrepancies in measurement, but can be quite informative nonetheless.

This self-verification technique, while originally mentioned in Connelly's work, is essentially a workaround based on the assumption of the straight edge's accuracy. There are various factors that can prevent yielding a true result from this test, which makes it more applicable for temporary adjustments in workshop settings rather than for broader measurements using a surface plate.

The history of the surface plate reveals its initial development by Henry Maudslay and Joseph Whitworth aimed at creating precision tools. Originally made of cast iron, the first commercial surface plates surfaced in the market thanks to the Crown Windley company. However, during the metal shortages of World War II, granite was adopted as a strong, corrosion-resistant alternative that became widely used. Today, granite surface plates have advanced to be essential tools in engineering and manufacturing, where the need for precision is paramount.

At Hengfeng, we prioritize quality and excellence, providing superior high value-added products as we deliver our offerings worldwide. To maintain the integrity and performance of your surface plate, adhere to the following care instructions:

• Proper Installation Techniques
  • Utilize the original support system designed for your surface plate, including any rubber padding necessary to ensure its accuracy and stability.
• Regular Maintenance
  • Inspect the plate periodically for any signs of wear or damage and perform resurfacing when necessary to ensure accurate measurements.
• Maintain Cleanliness
  • Use specific granite cleaning products to avoid inaccuracies stemming from a dirty surface.
• Proper Use of Surface Plates
  • Never store tools or other items on surface plates, as this can lead to wear and potential measurement errors.

By following these tips, you not only enhance the lifespan of your surface plate but also ensure the reliability of the measurements taken, which are crucial for quality control processes. For more information on the Inspection Surface Plate and other related products, please feel free to contact us for professional guidance.