How to Measure Bolt Size. In the example, there are 12 threads per inch , so the measure reads as 12. Measure the length of the shank. The length of the shank is from the point where it meets the head to the opposite end. In the example, this is 4 inches . To Determine the Size of a Bolt . First measure the diameter . Diameter is in either Inches ( not decimal ) or Millimeter. Second measure the pitch. Pitch is threads / per unit. Inches are measured threads per inches. Metric are measured thread per millimeter. Head Diameter . heremon for people to refer to hex bolts by the size of the head measured across the flats (this is also the size wrench the bolt uses). This is incorrect and should be avoided for two reasons. heremunication can result in getting a much larger bolt than needed.

How to Measure Bolt Thread Size Video of the Day. Measuring with a Ruler. Bolts produced in the United States for American products are measured in. Measuring with a Thread Pitch Gauge. There are other methods for measuring both metric. Other Considerations. Length of a bolt can also be measured from the top of the head of a bolt to the end of the shank for certain types of bolts . These include oval head screws, flat head screws, elevator bolts and plow bolts . Any screw that sinks in to form a level surface when properly installed should be measured from the top of the head to the end of the fastener. Finding a Wrench for Standard-and Metric-Sized Bolts. For example, for the numbers in Step 1, 1/2 x 1.5 = .75 or 3/4, which is the wrench size needed for this standard-sized bolt. Measure the distance across the flats of the bolt's head using a vernier caliper if the bolt …

Bolt size is measured from the end of the threads to the bottom of the bolt head. The bolt head diameter makes no difference in general measurements . When threads are cut or rolled the outside diameter will be reduced a bit. So a 5mm bolt will have a thread diameter measurement of … How to Measure a U-Bolt . The U-bolt size is given as Diameter (A) x Distance (B) x Leg Length (C). Additionally the bend type must also be given to avoid problems in specifications of semi-round bend shapes. Forged top U-