Bolts doubt

[rubenpezu]

Hello,
I have just talking with a costumer about the use of different quality bolts. In Europe case 5.6 Vs 8.8 (according ISO 898-1) and in US case T0 Vs T1 (according ASTM A394) I think with steel S275 and S355 (Europe) or A36 and A572 Grade 50.
The question is that he explain me that is not good use bolts 8.8 (A394 T1) with material S275 and S355 (A36 and A572 Grade 50) because the angles suffer more than in normal situation with bolts 5.6 (A394 T0).
And other question is that sometimes when our costumer ask for more bolts because are missing or there are lack of them and we don’t have in our workshop bolts 5.6 (A394 T0) we send bolts 8.8 (A394 T1) in order to be quicker as possible. He said that this is not correct.
Can anyone help me to clarify both issues?
Thank you very much.

 

[transmissiontowers]

The T1 bolts are high strength and are equivalent to ASTM A-325 but with a smaller head. The T0 bolts are more like A307. Both T1 and T0 have limited thread length to keep the threads out of the shear plane because they transfer the loads between members as shear and not by clamping the members together to transfer by friction. T1 bolts are more expensive than T0. The T0 bolts are harder than the A36 or 50 ksi angles that they connect and the T1 are even harder so the angle bolt hole will deform under severe load with either bolt.

I'm not sure if I understand the question, but you can check the PLS-Tower output and see the capacity of the member and what is the limiting factor. Very thin angles of A36 may be limited by the bearing allowable. The shear through the bolts could also be the limiting factor.

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I have been called "A storehouse of worthless information" many times.

 

[rubenpezu]

Thanks for your answer.

My doubt is that one client say us that is not recommendable use bolts 8.8 (equivalent more or less to T1) in the steel lattice towers. In my opinion there are no problem when you check the PLS-TOWER output and everything is under the limit the calculation are OK.

Is there a problem for use T1 bolts high strength (Europe 8.8) in a steel lattice tower? In my opinion no but I want to know other points of view.

 

[transmissiontowers]

There should be no problem at all using High Strength bolts with any steel angles because the bolts are much harder than the steel member it is connecting. In the USA we do it all the time. I don't know about Europe.

_____________________________________
I have been called "A storehouse of worthless information" many times.

 

[rubenpezu]

Thanks a lot. We also do. This time was the first time I heard.