Steel: Field Bolt Shop Weld

This is a quick and short video to remind you that field bolting versus shop welding. You don't want to field weld. That's too expensive. Welding on the field is very expensive. So whenever possible, you want to weld in the shop and bolt in the field. It's a lot cheaper to do field bolting than field welding. This piece has been welded in the shop. Shop weld and field bolt. That's the ideal situation money-wise. Because at the fabricator, you have your licensed welders. They have their equipment. They do this every day. But for them to take their equipment and to have a weld certified on the field, is very expensive. And besides, with current technology, robots are doing a lot of the welding, and that is a lot cheaper than having to do it on the site. Very good. Let's briefly look at these three animations and notice one thing, that no matter where the bolted connection is, The nut is always to the top. And the reason is very simple. Because there's a guy sitting on this beam in midair with a heavy gun. And it's very difficult to come underneath. If you put the nut underneath, it's very difficult to get there with the wrench to tighten that nut. So it's always easier to have the nuts accessible from the top with the gun to tighten them. The other reason I wanted to talk about these animations very quickly is to understand what type of stress the bolt is under. So when this is loaded, it wants to bend. And these guys, anything on the web is always in sheer. All the bolts on the web are always in shear. These four bolts are always in shear. Now, as this plate wants to separate because it's being pulled out, then these bolts are in shear. And as this flange pushes towards, because we have a couple, that's what happens when the beam is bending. then these guys are also in shear but that's different with this configuration because these guys as we said in a previous video are being pulled out and therefore these guys are intention and these two on the bottom are in compression because the flange is pushing forward versus the top flange is pulling out and all the bolts on the web are in shear. So the top two outside the flange are in tension and so is this plate. It's fighting against those two bolts. The two bottom bolts are in compression and so is this plate. This web stiffener is the bottom one is in compression. The top one is in tension. I hope this helps.