ASME B18.5 Round Head Fin Neck Bolts

                                                                                

Nominal Size	Body Dia., E		Head Dia., A		Head Height, H		Fin Thick., M		Dist.Across Fins, O		Fin Depth, P
	Max	Min	Max	Min	Max	Min	Max	Min	Max	Min	Max	Min
ASME B18.5 - No. 10	0.199	0.182	0.469	0.438	0.114	0.094	0.098	0.078	0.395	0.375	0.088	0.078
ASME B18.5 - 1⁄4	0.26	0.237	0.594	0.563	0.145	0.125	0.114	0.094	0.458	0.438	0.104	0.094
ASME B18.5 - 5⁄16	0.324	0.298	0.719	0.688	0.176	0.156	0.145	0.125	0.551	0.531	0.135	0.125
ASME B18.5 - 3⁄8	0.388	0.36	0.844	0.782	0.208	0.188	0.161	0.141	0.645	0.625	0.151	0.141
ASME B18.5 - 7⁄16	0.452	0.421	0.969	0.907	0.239	0.219	0.192	0.172	0.739	0.719	0.182	0.172
ASME B18.5 - 1⁄2	0.515	0.483	1.094	1.032	0.27	0.25	0.208	0.188	0.833	0.813	0.198	0.188
All dimensions are given in inches unless otherwise specified. *Maximum fillet radius R is 0.031 inch for all sizes. For information as to threads and method of bolt designation, see foonotes to the preceding table.