1/4"-28 Weld Nuts | McMaster-Carr

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20 Products

Weld Nuts

Add permanent threads to thin metal with our go-to weld nuts. Unlike press-fit and rivet nuts, these nuts fuse to the base metal, so they won’t twist and pull out. Three evenly spaced projections concentrate heat away from the threads to prevent them from deforming and create consistent welds. All have a collar pilot that guides the nut into the hole, holds it in place while welding, and protects the threads from weld spatter. You can also install them on thick pieces of metal.

Steel—Best for dry environments since moisture will cause them to rust. Made of uncoated steel, these nuts require minimal prep. Weld them to uncoated steel surfaces.

18-8 Stainless Steel—Suitable for outdoor use, these nuts resist rust from water and mild chemicals. Weld them to stainless steel surfaces.

				Collar
	Thread Size	Wd.	Ht.	Dia.	Ht.	For Hole Dia.	Specs. Met	Pkg. Qty.		Pkg.
Steel



		1/4"-28	1/2"	3/16"	13/32"	0.04"	27/64"	ASME B1.1	25	93560A230	000000


		18-8 Stainless Steel



				1/4"-28	1/2"	3/16"	13/32"	0.04"	27/64"	ASME B1.1	10	95508A400	0000

Tube End Weld Nuts

Weld these nuts into tube ends to attach threaded fittings such as rod ends. The welded connection is stronger than tapping a tube directly. These nuts are often used to link control arms and suspensions. Also known as tube adapters and weldable threaded tube ends.

	Threading	Thread Lg.		Each
4130 Alloy Steel







	For 1/2" OD Tubes

	0.058"	1/4"-28	1"	Fully Threaded	1"	94640A881	00000

Low-Profile Rectangular Weld Nuts

Weld permanent threads in channels and other tight spaces without adding a barrel bump that gets in the way. These nuts have a short barrel that tucks under low surfaces and a slim footprint that fits between narrow channel walls.

Steel—Best for dry environments since moisture will cause them to rust. Made of uncoated steel, these nuts require minimal prep. Weld them to uncoated steel surfaces.

18-8 Stainless Steel—Suitable for outdoor use, these nuts resist rust from water and mild chemicals. Weld them to stainless steel surfaces.

Number of Projections—More projections lead to more consistent welds by concentrating heat and protecting the threads from deforming.

			Base			Barrel
	Thread Size	No. of Projections	Lg.	Wd.	Thk.	Dia.	Ht.	For Hole Dia.	Certificate Type	Pkg. Qty.		Pkg.
Steel



		1/4"-28	2	13/16"	1/2"	1/8"	19/64"	1/16"	19/64"	—	10	92006A130	00000


		18-8 Stainless Steel



				1/4"-28	2	13/16"	1/2"	1/8"	19/64"	1/16"	19/64"	Material Certificate	10	98697A770	00000

Square Weld Nuts

With four symmetrical projections, these nuts create the strongest hold in our offering. Unlike rectangular weld nuts, each projection is equidistant from the threads, so welds wrap evenly for extra strength and twist resistance. Projections concentrate heat away from the threads to prevent them from deforming and create consistent welds. All nuts have a collar pilot that guides them into the hole, holds them in place while welding, and protects the threads from weld spatter.

Steel—Best for dry environments since moisture will cause them to rust. Made of uncoated steel, these nuts require minimal prep. Weld them to uncoated steel surfaces.

				Collar
	Thread Size	Wd.	Ht.	Dia.	Ht.	For Hole Dia.	Specs. Met	Pkg. Qty.		Pkg.
Steel



		1/4"-28	1/2"	5/32"	13/32"	0.063"	27/64"	ASME B1.1	50	93975A120	000000

Rectangular Weld Nuts

These nuts add permanent threads in narrow spaces such as channels. With a slim footprint, they fit where round weld nuts can’t. Plus, their barrel is twice as long as low-profile barrels, so more threads connect with your bolt for a secure hold. You can weld these nuts in two orientations: on top of a flat surface or with the barrel sticking through a hole.

Steel—Best for dry environments since moisture will cause them to rust. Made of uncoated steel, these nuts require minimal prep. Weld them to uncoated steel surfaces.

Number of Projections—Weld these nuts on top of metal—the projections on the bottom will fuse to the surface. More projections lead to more consistent welds by concentrating heat and protecting the threads from deforming.

			Base			Barrel
	Thread Size	No. of Projections	Lg.	Wd.	Thk.	Dia.	Ht.	Pkg. Qty.		Pkg.
Steel



		1/4"-28	0	3/4"	1/2"	3/64"	5/16"	21/64"	50	90594A040	000000

Offset-Barrel Low-Profile Rectangular Weld Nuts

Add permanent threads on corners and near edges. With a slim base and a short, offset barrel, these weld nuts fit in tight spaces such as channels and low-clearance areas.

Steel—Best for dry environments since moisture will cause them to rust. Made of uncoated steel, these nuts require minimal prep. Weld them to uncoated steel surfaces.

Zinc-Plated Steel—A step up from plain steel, these nuts withstand occasional exposure to moisture. Weld them to uncoated steel surfaces. If MIG or TIG welding, grind the zinc plating off the part of the nut you intend to weld.

18-8 Stainless Steel—Suitable for outdoor use, these nuts resist rust from water and mild chemicals. Weld them to stainless steel surfaces.

Number of Projections—More projections lead to more consistent welds by concentrating heat and protecting the threads from deforming.

			Base			Barrel
	Thread Size	No. of Projections	Lg.	Wd.	Thk.	Dia.	Ht.	For Hole Dia.	Pkg. Qty.		Pkg.
Steel



		1/4"-28	0	13/16"	1/2"	1/8"	19/64"	1/16"	5/16"	25	94579A450	00000


		Zinc-Plated Steel



				1/4"-28	0	13/16"	1/2"	1/8"	19/64"	1/16"	5/16"	10	94579A780	0000


				18-8 Stainless Steel



						1/4"-28	0	13/16"	1/2"	1/8"	19/64"	1/16"	5/16"	10	94581A136	00000

Left-Hand-Thread Tube End Weld Nuts

These weld nuts prevent fasteners from backing out of assemblies that rotate counterclockwise. Their left-hand threads pair with left-hand screws and rods to stop the fastener from loosening as the assembly turns. Weld them to the end of a tube for a stronger connection than tapping the tube directly. Also known as tube adapters and weldable threaded tube ends.

	Threading	Thread Lg.		Each
4130 Alloy Steel







	For 1/2" OD Tubes

	0.058"	1/4"-28	1"	Fully Threaded	1"	94640A882	00000

Self-Aligning Rectangular Weld Nuts

Help screws pass through perfectly every time. These nuts float inside a rectangular retainer that shifts and tilts to compensate for misalignment. A pilot tip locates the hole, and the retainer holds the nut in place during welding.

Steel with Steel Retainer—Best for dry environments since moisture will create rust. Weld them to steel surfaces.

		Base
	Thread Size	Lg.	Wd.	Thk.	Ht.	Pkg. Qty.		Pkg.
Steel with Steel Retainer



		1/4"-28	1 3/4"	9/16"	1/16"	7/16"	10	90955A113	000000

Stainless Steel Adhesive-Ready Nuts

Add strong threads to material that’s too difficult to drill or too thin to grip a threaded insert. These nuts are ideal for brittle plastics or tough composites, such as acrylic or carbon fiber. They have large holes in the base so that adhesive or resin can flow through, spread out, and create an extra-strong hold. You can also mold them into the surface of your material. Made of 316 stainless steel, they resist corrosion from salt water and harsh chemicals.

The base of these nuts acts like a flange, distributing pressure evenly across the mounting surface. The larger the base, the more that pressure is spread out; the smaller the base, the tighter the space these nuts can fit into. Taller nuts engage more of a screw’s threads than shorter nuts. Shorter nuts fit in low-clearance areas.

		Base		Nut
	Thread Size	Dia.	Thk.	Wd.	Ht.	Hole Dia.	Pkg. Qty.		Pkg.
316 Stainless Steel



		1/4"-28	29/32"	3/64"	3/8"	1/2"	13/64"	1	98007A473	00000


		1/4"-28	29/32"	3/64"	7/16"	7/32"	13/64"	5	98007A456	0000
		1/4"-28	1 1/2"	3/64"	3/8"	1/2"	11/64", 13/64"	1	98007A474	0000
		1/4"-28	1 1/2"	3/64"	7/16"	7/32"	11/64", 13/64"	5	98007A457	00000

Stainless Steel Narrow-Base Adhesive-Ready Nuts

Add corrosion-resistant threads to channels, corners, and other tight spaces without drilling a hole. Glue these nuts on to thin surfaces and materials too hard and brittle to drill, such as acrylic and carbon fiber. Large holes in the base allow adhesive and resin to flow and spread along the joint for a good bond. You can mold them into plastics or composites. Made of 316 stainless steel, these nuts are excellent at resisting chemicals and salt water.

The base of these nuts acts like a flange, distributing pressure evenly across the mounting surface. Larger bases spread the pressure over more surface for a strong bond, while smaller bases fit better in tight spaces.

		Base			Nut
	Thread Size	Lg.	Wd.	Thk.	Wd.	Ht.	Hole Dia.	Pkg. Qty.		Pkg.
316 Stainless Steel



		1/4"-28	15/16"	29/64"	3/64"	7/16"	7/32"	13/64"	5	93512A240	000000


		1/4"-28	1 1/2"	19/32"	3/64"	7/16"	7/32"	13/64"	5	93512A250	00000

Steel Narrow-Base Adhesive-Ready Nuts

Fit these nuts into channels, corners, and other tight spaces to add strong threads without drilling a hole. They’re ideal for material that’s too thin or too hard and brittle to drill, such as acrylic and carbon fiber. For a strong hold, large holes in the base let adhesive and resin flow through and spread out. You can also mold these nuts into plastics or composites. Thanks to a zinc plating, they resist rusting in wet environments.

		Base			Nut
	Thread Size	Lg.	Wd.	Thk.	Wd.	Ht.	Hole Dia.	Pkg. Qty.		Pkg.
Zinc-Plated Steel



		1/4"-28	15/16"	29/64"	3/64"	7/16"	7/32"	13/64"	10	93552A240	00000


		1/4"-28	1 1/2"	19/32"	3/64"	7/16"	7/32"	13/64"	5	93552A250	0000