Open Ended Lab

[Audio] Assalam-u-alaikum all, myself Abdul-muqeet and these are my group members Numan Ahmad, Hassan Shahzad , Hussain Iqbal , Asad Ali , Ameer Hamza Asif , Muhammad Sami , Mohamed Omar Abdi.

[Audio] As per project bolts nuts and washers are to be used for testing the astm standards we were directed A307 and A325 and The consultants representaive at the site must ensure the quality of the used materials as per given standards otherwise it will all result in directly a huge loss of client who assigned you the job..

[Audio] Now come to our specimens and firt of all boults are here ,boults as you know are used for binding two or more members of any type of material togather Bolts we used were bought from market as per given standard A307 and A325 the sample is shown in figure below.

[Audio] Now it come to nuts Nuts are almost always used in junction with a bolt to fasten multiple parts together Nuts we used are also bought from the same same supplier from which we bought boults but that were not of good quality we asked him to give as per standard but he gave local one which effect also in tension testing ,during test threads of nuts fail and damage the whole arrangments.

[Audio] Here is washer Washers are also used along with nuts to provide a gripped fastening against boults To avoid slippage of nuts by axtra tightning washers provided inbetween nuts and boults as shown figure.

[Audio] ASTM Standards ASTM A325 This standard is mostly used for making of bolts used in communication tower. This specification covers two types of quenched and tempered steel heavy hex structural bolts having a size over 1.0 to 11 2 ⁄ in ASTM A307 This specification covers the chemical and mechanical requirements of two grades of carbon steel bolts and studs in sizes 1 4 ⁄ in. through 4 in.

[Audio] Here comes the tests we have to perform two tests hardness and second one is bending Apparatus we used is Rockweell Hardness Testing Machine hardness results are shown here.

[Audio] These are some photographs we have captured during testing.

[Audio] Tension Test is here again the appratus we used is 500KN Shimadzu Universal Testing Machine and arragment is shown in figure as you see.

[Audio] Necking is an effect occure during tension of a specimen due to necking ( cup and cone shape formation) the cross-sectional area is reduced.

[Audio] Here is the Stress Strain Curve and important points here are yield strenght ultimate strenght necking and fracture.

[Audio] These are results taken from experiments both for hardness and bending test.

[Audio] Now i would conclude my presentation but before conclusion here are some points i wanna mention We preformed two experiments on the same specimen, one was tension and the other was hardness test. On the basis of these experiments we computed two table in which we compared our calculations with the standards. We purchased bolts from market, the shopkeeper claimed these are of grade 8.8The whole section was into 5 groups. All were asked to buy their specimen of same grade but from different shops. All of the groups performed the same experiments. Although in the end they all come to know that their specimens are of grade 8.8 but there was a difference in the calculated values of these groups. This difference was due the difference of material.

[Audio] Thank you for your time and attention Allah hafiz.