REF: Hex, Socket (Allen) and Torx Bolt and Screw Wrench Sizes

With the charts below and knowing or deducing the nut / bolt thread size, you can figure what size wrench is needed.
If you are not sure of the thread size, you can reference the Hardware P/N & Descriptions pages in the Sportsterpedia to find bolt sizes for IH and Evo Sportsters.
And likewise, if you know the wrench size, you can deduce the thread size (barring course or fine threading).

Hex Bolt and Socket (Allen) Screw Wrench Sizes


US Hex Bolt and Socket (Allen) Screw Wrench Size			Metric Hex Bolt and Socket (Allen) Screw Wrench Size
Nominal Thread Diameter	Hex Bolt Wrench Size	Hex Socket Wrench Size	Nominal Thread Diameter	Hex Bolt Wrench Size	Hex Socket Wrench Size
#6	1/4“	-	M4	7mm	3mm
#8	1/4”	-	M5	8mm	4mm
#10	5/16“	-	M6	10mm	5mm
#12	5/16”	-	M8	13mm	6mm
1/4“	7/16”	3/16“	M10	17mm	8mm
5/16”	1/2“	1/4”	M12	19mm	10mm
3/8“	9/16”	5/16“	M14	22mm	12mm
7/16”	5/8“	3/8”	M16	24mm	14mm
1/2“	3/4”	3/8“	M18	27mm	14mm
9/16”	1-3/16“	7/16”	M20	30mm	17mm
5/8“	1-5/16”	1/2“	M22	32mm	17mm
3/4”	1-1/8“	5/8”	M24	36mm	19mm
7/8“	1-5/16”	3/4“	M30	46mm	22mm
1”	1-1/2“	3/4”
1-1/8“	1-11/16”	7/8“
1-1/4”	1-7/8“	7/8”
1-3/8“	2-1/16”	1“
1- 1/2”	2-1/4“	1”
1-3/4“	2-5/8”	1-1/4“
2”	3“	1-1/2

Torx Screw Wrench Sizes


Screw Size	Torx Socket Set Screw	Torx Socket Cap Screw	Torx Pan Head Screw	Torx Flat Head Screw	Torx Fillister Head Screw	Torx Truss Head Screw	Torx Oval Head Screw	Torx Hex Head Screw	Torx Internal Washer Head Screw
#2	T3	-	T7	T6	-	-	-	-	T7
#3	T5	-	T8	T7	-	-	-	-	T8
#4	T6	T10	T9	T8	T9	-	-	T9	T9
#5	T7	T10	T10	T9	T10	-	T10	T10	T10
#6	T7	T15	T15	T10	T15	T10	T15	T15	T15
#8	T8	T25	T20	T15	T20	T15	T20	T20	T20
#10	T10	T27	T25	T20	T25	T20	T25	T25	T25
#12	T10	T27	T27	T25	T27	T25	T27	T27	T27
1/4”	T20	T30	T30	T27	T30	T27	T30	T30	T30
5/16“	T27	T45	-	T40	T40	T30	T40	T40	-
3/8”	T30	T50	T45	T40	T45	T40	T45	T45	-
7/16“	T40	T55	T50	T50	T50	T45	T50	-	-
1/2”	T45	T55	T55	T55	T55	T50	T50	-	-

SAE to Metric Hex Wrench Conversions

When you reference the hex wrench chart below, be aware that using a larger size wrench will increase the chances of stripping the bolt head corners. In some cases, you may want to try using a size above the one recommended in the chart to see if it fits by chance. Not every metric size has a perfect SAE counterpart and vice-versa. There is no perfect substitute for the right size tool.


SAE Hex Wrench Size	5/16“	3/8”	7/16“	1/2”	9/16“	5/8”	3/4“	13/16”	7/8“	15/16”
SAE Bolt Size	1/8“	3/16”	1/4“	5/16”	3/8“	7/16”	1/2“	9/16”	9/16“	5/8”
Metric Hex Wrench Size	8mm	10mm	11mm	13mm	14mm	16mm	19mm	21mm	22mm	24mm

SAE to Metric Hex Key (Allen Head) Conversions

When you reference the hex key chart below, be aware that using a smaller size bit will increase the chances of stripping the corners. ¹⁾ In some cases, you may want to try using a size above the one recommended in the chart to see if it fits by chance. Not every metric size has a perfect SAE counterpart and vice-versa. There is no perfect substitute for the right size tool.