Screw Information:

HEAD TYPES
FLAT TRUSS	PAN HEAD	ROUND HEAD	ROUND WASHER	HEX HEAD
HEX WASHER	TRUSS HEAD	OVAL HEAD	FLAT HEAD	TRIM HEAD
ONE-WAY HEAD	MOD TRUSS	BUGLE HEAD	PANCAKE HEAD	WAFER HEAD

HOW TO MEASURE A SCREW:
FLAT	ROUND	OVAL	HEX	PAN	TRUSS

SCREW SIZE
Nominal Size	Basic Screw Diameter	Actual Size
0	0.0600
1	0.0730
2	0.0860
3	0.0990
4	0.1120
5	0.1250
6	0.1380
7	0.1510
8	0.1640
10	0.1900
12	0.2160
1/4	0.2500
5/16	0.3125
3/8	0.3750
Where specifying nominal size in decimals, zeros preceding decimal and in the fourth decimal place shall be omitted. Sizes shown in highlighted are preferred.

TO SELECT PHILLIPS DRIVER SIZE
Screw Type	SCREW DIAMETER & HEAD STYLE
	Oval, Pan & Flat	Round & Fillister	Truss	Size of Bit or Driver
Machine & Tapping Screws	0-1	0-1	0-1	0
	2-4	2-4	2-4	1
	5-10	5-10	5-10	2
	12-14	12-5/16	12-14	3
	5/16-1/2	3/8-1/2	5/16-1/2	4
Wood Screws	0-1	0-1	0-1	0
	2-4	2-4	2-4	1
	5-9	5-10	6-10	2
	10-16	11-16	12-16	3
	18-24	18-24	18-24	4

METRIC CONVERSION CHART
Frac. (in.)	Dec. (in.)	mm		Frac. (in.)	Dec. (in.)	mm
1/64	0.015625	0.3969		33/64	0.515625	13.0969
1/32	0.031250	0.7938		17/32	0.531250	13.4938
3/64	0.046875	1.1906		35/64	0.546875	13.8906
1/16	0.062500	1.5875		9/16	0.562500	14.2875
5/64	0.078125	1.9844		37/64	0.578125	14.6844
3/32	0.093750	2.3812		19/32	0.593750	15.0813
7/64	0.109375	2.7781		39/64	0.609375	15.4781
1/8	0.125000	3.1750		5/8	0.625000	15.8750
9/64	0.140625	3.5719		41/64	0.640625	16.2719
5/32	0.156250	3.9688		21/32	0.656250	16.6688
11/64	0.171875	4.3656		43/64	0.671875	17.0656
3/16	0.187500	4.7625		11/16	0.687500	17.4625
13/64	0.203125	5.1594		45/64	0.703125	17.8594
7/32	0.218750	5.5563		23/32	0.718750	18.2563
15/64	0.234375	5.9531		47/64	0.734375	18.6531
1/4	0.250000	6.3500		3/4	0.750000	19.0500
17/64	0.265625	6.7469		49/64	0.765625	19.4469
9/32	0.281250	7.1438		25/32	0.781250	19.8437
19/64	0.296875	7.5406		51/64	0.796875	20.2406
5/16	0.312500	7.9375		13/16	0.812500	20.6375
21/64	0.328125	8.3344		53/64	0.828125	21.0344
11/32	0.343750	8.7312		27/32	0.843750	21.4312
23/64	0.359375	9.1281		55/64	0.859375	21.8281
3/8	0.375000	9.5250		7/8	0.875000	22.2250
25/64	0.390625	9.9219		57/64	0.890625	22.6219
13/32	0.406250	10.3188		29/32	0.906250	23.0188
27/64	0.421875	10.7156		59/64	0.921875	23.4156
7/16	0.437500	11.1125		15/16	0.937500	23.8125
29/64	0.453125	11.5094		61/64	0.953125	24.2094
15/32	0.468750	11.9062		31/32	0.968750	24.6062
31/64	0.484375	12.3031		63/64	0.984375	25.0031
1/2	0.500000	12.7000		1	1.000000	25.4000