The diameter of the bolt in millimeters can be calculated by converting inches to millimeters. Since 1 inch is equal to 25.4 millimeters, a thread diameter of 1.25 inches would be:
1.25 inches × 25.4 mm/inch = 31.75 mm
So, the diameter of the bolt is 31.75 millimeters.
If the order was mistaken for 1.25 centimeters, we first convert centimeters to millimeters. Since 1 centimeter is equal to 10 millimeters, 1.25 centimeters would be:
1.25 cm × 10 mm/cm = 12.5 mm
To find out by how many millimeters the bolt would be in error, we subtract the mistaken diameter from the correct diameter:
31.75 mm – 12.5 mm = 19.25 mm
Therefore, the bolt would be 19.25 millimeters smaller in diameter if the order was mistaken for 1.25 centimeters instead of 1.25 inches.