Imperial Machine Screw Sizes.

I had a hard time finding this in such a convenient table, so I've copied this here.

Machine Screw Size	Number of Threads Per Inch	Minor Dia.	Tap Drills				Clearance Hole Drills
	Aluminum, Brass & Plastics 75% Thread	Stainless Steel, Steels & Iron 50% Thread	All Materials
			Close Fit	Free Fit
No. or Dia.	Major Dia.	Drill Size	Decimal Equiv.	Drill Size	Decimal Equiv.	Drill Size	Decimal Equiv.	Drill Size	Decimal Equiv.
0	.0600	80	.0447	3/64	.0469	55	.0520	52	.0635	50	.0700
1	.0730	64	.0538	53	.0595	1/16	.0625	48	.0760	46	.0810
72		.0560	53	.0595	52	.0635
2	.0860	56	.0641	50	.0700	49	.0730	43	.0890	41	.0960
64		.0668	50	.0700	48	.0760
3	.0990	48	.0734	47	.0785	44	.0860	37	.1040	35	.1100
56		.0771	45	.0820	43	.0890
4	.1120	40	.0813	43	.0890	41	.0960	32	.1160	30	.1285
48		.0864	42	.0935	40	.0980
5	.1250	40	.0943	38	.1015	7/64	.1094	30	.1285	29	.1360
44		.0971	37	.1040	35	.1100
6	.1380	32	.0997	36	.1065	32	.1160	27	.1440	25	.1495

Atrium Measurements

width: 63'
height to top of horiz beams: 32'
south bridge: 20' 8" to walkway, 24' 2" to railing
north bridge: 16' 9" to walkway, 20' 3" to railing
length, bridge to bridge: 143'