diameter hole needed for welding solid round bar inside flat bar

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Hi,I am trying to weld some round bar inside a hole in flat bar as in the picture provided. How large a hole do I need to drill? The round bar is 16mm diameter and the flat bar is 10mm thick if that makes any difference. I thought to make to hole exactly 16mm that way there is no wiggle room and the weld is just there to hold it in place but I have no idea about this. Any advice greatly appreciated! Also I am looking to make a part like the one attached second, with some CHS welded onto flat bar. Would it be more secure to cut a hole the diameter of the CHS and do as in the above and have the CHS sit in the flat bar and weld around it or would it be ok to just have it flush with the surface and do either a fillet or v weld around it? The CHS is 25NB Heavy and the flat bar is 5mm thick.For reference the first job is for a j cup used to hold a barbell (2 of them should be able to hold up to 500kg) and the second one is for a chinup bar that will be required to hold at most 150kg (welded on both sides).Thanks!
Reply:Well I can tell you a slip fit is better than a loose fit. So the tighter the hole, the more sound the joint IMO. Still a good bevel is in order.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:If your welding it then the fit doesn't really matter. You would just have to make sure it is square to the flat.
Reply:when i am building a prison style gate i drill 13/16" holes for a 7/8" round. the 7/8" bar slips easily into the hole without being sloppy.i.u.o.e. # 15queens, ny and sunny fla
Reply:Hot rolled/ cold rolled stock will also change the actual diameter vs the nominal diameter of the stock..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Hello docwelder, did you mean to say a 15/16" hole?  Best regards, Allanaevald
Reply:As mentioned, the hole should be a tight slip fit for the round stock.Then bevel the hole and chamfer the rod.Weld for penetration and you should be good to go. I rebuilt an idler on a finish mower years ago that was constructed that way. Held up 3 years and was sold wiring last fall.Be wary of The Numbers: Figures don't lie,. but liars can figure.Welders:2008 Lincoln 140 GMAW&FCAW2012 HF 165 'toy' GTAW&SMAW1970's Cobbled together O/A
Reply:It seems like a pretty simple job. Drill a hole(doesn't have to be a tight fit) the round bar fit's in, slide it in a couple mm's and run a fillet weld around it from the backside. Done! An 8mm fillet around the circumference of a 16mm bar isn't going to break. With the round just slightly slid in the hole and welded with a fillet weld, it will be stronger than if the bar was slid through flush and welded with just a flat bead.