- Woburn, Massachusetts, United States
- Mar 27th
Original Vintage Advertising Card measures approximately 3-1/2" x 6", and is printed on sturdy plastic similar to the stock used for making pocket calendars. The two sided chart contains machine screw and fractional tap drill sizes and percentage of threads. The chart includes sections for tap nominal size, tap drill, decimal equivalent and actual percentage of thread, straight and taper pipe tap drill sizes.