Ring Mandrel | Durston Steel Tapered | 112322

Made by Durston, this precision steel ring mandrel is machined and calibrated to the Durston steel finger gauge set and aluminum ring stick to provide excellent consistency from showroom to bench to customer.• Mandrel is laser-engraved in quarter size increments, 1-16 U.S.• Tapered for forming, sizing and shaping rings Brand: Durston Dimensions: 14-1/8L (358.8mm) Shipping weight: 3.600 lbs (1.634kg) Size: 1-16 (quarter-sizes) Country of origin: United Kingdom How To Size Rings Accurately To ensure an accurate ring size (or an accurate size on any circular jewelry piece), add the wire diameter (or the bar-stock thickness) to the finished inside diameter you want and multiply by pi (3.14). 1  Start with the desired inside diameter of the finished ring. 2  Add the wire diameter or metal thickness. 3  Multiply the result by pi (3.14). 4  This is the length of material you will need to cut to achieve your desired final result.         Measuring A Ring Blank To get a proper ring fit, you must compensate for the thickness of the ring band when measuring the blank. Forcing the outside ends of the blank together for soldering compresses the inside circumference, making the ring smaller. To correct for this, add about 3.14 times the thickness of the blank to the length before cutting it. If the ring band is wider than 4mm, add an extra 0.5mm. United States &Canadian StandardInside Diameter inches (mm)Inside Circumference inches (mm) 4 .585 (14.86) 1.836 (46.5) 5 .618 (15.70) 1.941 (49.0) 6 .650 (16.51) 2.042 (51.5) 7 .683 (17.35) 2.146 (54.0) 8 .716 (18.19) 2.249 (56.6) 9 .748 (18.99) 2.350 (59.1) 10 .781 (19.84) 2.463 (61.6) 11 .814 (20.68) 2.567 (64.1) 12 .846 (21.41) 2.658 (67.3)

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