Just a Small Introduction about fasterners and comparision with Metric and English Standards

1. By Mr. S.Palaniyappan

2. Fasteners Introduction : Fasteners are one of the temporary joint used in any engineering. Examples are Hex bolt, Alen Bolt, U bolt, Eye bolt, Hex nut, Square nut, stud etc., Whereas welding, riveting are permanent joint

3. Hex Bolt & Hex Nut In this presentation , we will discuss about Hex bolts and Hex Nuts. Hex bolts are having the hexagonal shaped heads. Hex nut has hexagonal Outer profile. Both Hex bolt and Hex Nut are available in metric standard as well as English standard.

4. Metric Designation of Hex Bolt Specified by Hex Bolt M16 X 1.5 x150 Grade10.9 M stands for Metric 16 refers major dia of the threads /dia of the Shank in millimeter 1.5 refers thread pitch in millimeter 150refers shank length of the bolt in millimeter. The figure shown aside will give us better understanding Grade refers strength of the bolt. In grade10.9 ,10means 100times of 10 gives us approximate value of tensile strength in MPa, if we need in KSI units, we have to multiply by 14.5 instead of 100.(Here 1000 MPa or 145 KSI) .9 refers yield strength of the bolt is equal to approximately 0.9 times tensile strength value.(i.e. 900MPa or 130.5 KSI)

5. Metric Designation of Hex Nut Specified by Hex Nut M16 X 1.5 Grade 10 M stands for Metric 16 refers major dia of the threads in millimeter. Never commit mistake by measuring minor dia of threads. 1.5 refers thread pitch. The figure shown aside will give us better understanding Grade refers strength of the bolt. Grade10 means ,this nut has equal strength as that of Grade 10.9 bolt.

6. English Designation of Hex Bolt Specified by Hex bolt 1.00-8*6.5Grade 8 1.00refers major dia of the threads /dia of the Shank in inches 8refers number of threads per inch 6.5refers shank length of the bolt in inches. The figure shown aside will give us better understanding Grade refers strength of the bolt. Only one digit is used to designate grade of English bolt Grade 8 English bolt has equal strength as that of Grade 10.9 metric bolt.

7. English Designation of Hex Nut Specified by Hex Nut 1.00-8 Grade C 1.00refers major dia of the threads in inches. Never commit mistake by measuring minor dia of threads. 8 refers number of threads per inch. The figure shown aside will give us better understanding Grades are designated by letter A,B,C. Grade C English nut has equal strength as that of grade 8 English bolt which is also equivalent to grade10.9 metric bolt.

8. Grade equivalent chart

9. …..continued. This chart is useful to find out grade equivalents of metric and English bolt , nuts. Mating bolt and nut should have the same strength.

10. Thank you all.