Spanner Sizes

Standard Spanner Sizes

Metric

UNF/UNC

Nominal Size	Spanner Size
M1.6	3.2mm
M2	4mm
M2.5	5mm
M3	5mm
M3.5	6mm
M4	7mm
M5	8mm
M6	10mm
M7	11mm
M8	13mm
M10	17mm
M12	19mm
M14	22mm
M16	24mm
M18	27mm
M20	30mm
M22	32mm
M24	36mm

Nominal Size	Spanner Size
no.0 Nut	5/32"
no.2 Nut	3/16"
no.4 Nut	1/4"
no.6 Nut	5/16"
no.8 Nut	11/32"
no.8 Bolt	1/4"
no.10 & 3/16" Nut	3/8"
no.10 & 3/16" Bolt	5/16"
1/4"	7/16"
5/16"	1/2" (9/16" for Dome Nut)
3/8"	9/16"
7/16" Full Nut	11/16"
7/16" Bolt & Nyloc Nut	5/8"
1/2"	3/4"
9/16" Nut	7/8"
9/16" Bolt	13/16"
5/8"	15/16"
3/4"	1 1/8"
7/8"	1 5/16"