Dimensions of Bolt

Finding the Right Bolt Size: Dimensions of Bolt

Going nuts in finding the right bolt? The simple secret is the thread. The threads are the ridges or edges that enclose or surround the bolt. Logically speaking, a thread too big for a bolt would not do or fasten or lock and same goes with a thread smaller than the bolt, fitting would be impossible. Signs like M5 or the like are keys in finding bolts. M simply stands for millimeter and the variable (say 5) is the size. Therefore, a five (5) millimeter bolt is a M5 bolt. However, standards of bolt measurements may vary depending on a location.

There are a lot of types of bolts that could be encountered in all ‘do-it-yourself’ shops or hardware stores. The bolt that has a concave threaded shaft or shank is the breakaway bolt. This kind of bolt is used in some airplanes but usually applied in fire hydrants. The bolt that has threads all the way to the top or head is called the tap bolt. The bolt that comes with the ‘wing’ (or nut) is referred as toggle bolt.

Bolts or Screws?

A clear characteristic is not necessary in dealing or understanding bolt sizes or dimension. Nonetheless, attempts in defining the differences of the two items are not that of great importance. However, both screws and bolt are definitely considered or taken as fasteners.

Standard Bolt Sizes

Grade mark, mechanical properties and nominal size range (in inches) had been the terminologies used in measuring bolt dimensions. Mechanical properties are tensile strength, yield strength and proof load. These given properties are measured in pound square inch or psi. SAE J429 fastener is made of medium carbon steel and ¼ to 1 ½ nominal size range. The tensile strength, yield and proof load are 60000, 36000 and 33000 respectively.

Low carbon steel composes bolts that were indicated as ASM A307 Grades A and B. This kind of bolt has a tensile strength of 60000 and nominal size range if ¼ to 4. The B8 ASTM A193 Grade B8 has a tensile strength of 80000, yield strength of 100000 and its nominal size range is ¼ to ¾. The ASTM A320 Grade L7 has a tensile strength of 125000 and yield strength of 105000. Grade B8T has a yield and tensile strengths are 30000 and 75000. Its nominal size is ¼ and bigger. Grade 5 of SAE J429 tensile, proof load and yield capacities are set to 120000, 85000 and 92000 correspondingly. Its nominal size is ¼ through 1 and above 1 to a half inch.

Comprehending bolt dimensions or sizes and their components are the factors in using them properly. Knowing some few tips would take the complexity out and in the just few familiarizations; using bolts would never be a problem.