M11 Fasteners | McMaster-Carr

The star-shaped head has more points of contact than a hex head nut, so you can achieve a better grip and a tighter fit without flattening the sides of the nut. Great for cramped spaces without a lot of clearance, these nuts twist on from any angle with a standard wrench. They have a flange that distributes pressure evenly across the mounting surface without the need for a separate washer. Also known as collar nuts.

Steel

Black-Oxide Steel—Typically chosen for their appearance, these nuts have a dark, matte coating that creates a finished look. They offer minimal corrosion resistance, so they're best for dry environments.

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.		Each
Black-Oxide Steel



		M11 × 1.25 mm	13	11	17.8	3.2	90759A870	$5.41


		M11 × 1.25 mm	14	13	20.9	3.2	90759A880	5.41

Corrosion-Resistant Stainless Steel

High-Temperature A286 Stainless Steel—Stronger than 316 stainless steel and withstand high temperatures up to 1500° F. These nuts resist corrosion from chemicals, such as bleach and chlorine, but they won't hold up to salt water as well as 316 stainless steel.

				Flange, mm
	Thread Size	Wd., mm	Ht., mm	Dia.	Thk.		Each
High-Temperature A286 Stainless Steel



		M11 × 1.25 mm	13	11	17.8	3.2	90997A290	$8.20


		M11 × 1.25 mm	14	13	20.9	3.2	90997A310	6.36

Helical Threaded Insert Installation and Prong Break-Off Tools

L-Handle

Install helical inserts and break off prongs with one tool and a hammer strike. These tools have a slot that grips your insert’s prong for turning both left- and right-hand threads. Slide an insert onto these tools and drive them a quarter-turn to half-turn below the material’s surface. Then, strike the end of the tool with a hammer to break off the prong. These tools work with pronged helical inserts.

For Pipe Size	Handle Style		Each



7/16"-14, 7/16"-16, 7/16"-20, M11 × 1 mm, M11 × 1.25 mm, M11 × 1.5 mm	1/8 BSPP	L-Handle	92450A182	$16.03

Helical Threaded Insert Installation Tools

No Handle

Install your pronged helical inserts into tapped holes. Screw an insert onto these tools and drive them a quarter to half-turn below the material’s surface.

Square Shank—These tools don’t have a handle. Attach them to a tap wrench to turn.

	Shank Type	For Use With		Each
Metric Thread



	M11 × 1.5 mm	Square	Helical Inserts, Screw-Locking Helical Inserts	93060A104	$23.53