This vintage Lufkin Tools Time Saver Circular Chart Slide Rule is a must-have for any collector or enthusiast of antique tools. Made in 1963, it features tap threads, drill screw and other useful measuring functions. Its unique circular design makes it a great addition to any workshop or display case. The slide rule is in good working condition and has been well-maintained over the years. Its sturdy construction ensures it will last for many more years to come. This tool is a great investment for anyone who appreciates the value of quality craftsmanship and precision engineering. Please look at pictures for more details. We will package securely and ship promptly.