BS 450 Mushroom Head Screws

Nom. Size of Screw	Basic Dia. D	Threads per Inch		Dia. of Head A		Depth of Head B		Width of Slot H		Depth of Slot J
Nom. Size of Screw	Basic Dia. D	BSW	BSF	Max.	Min.	Max.	Min.	Max.	Min.	Depth of Slot J
BS 450 - 1⁄8	0.125	40	...	0.289	0.272	0.078	0.066	0.043	0.035	0.04
BS 450 - 3⁄16	0.1875	24	32c	0.448	0.425	0.118	0.103	0.06	0.05	0.061
BS 450 - 1⁄4	0.25	20	26	0.573	0.546	0.15	0.133	0.075	0.064	0.079
BS 450 - 5⁄16	0.3125	18	22	0.698	0.666	0.183	0.162	0.084	0.072	0.096
BS 450 - 3⁄8	0.375	16	20	0.823	0.787	0.215	0.191	0.094	0.081	0.112
a All dimensions, except J, given for the 18-through 38-inch sizes also apply to all the 90° Raised Countersunk Head Screw dimensions given in the Standard. b These screws are also available with recessed heads; recess are not given here but may be found in the Standard. c Non-preferred size; avoid use whenever possible. d By arrangement may also be 0.309. e By arrangement may also be 0.468. All dimensions in inches.