Self-Sealing Hex Nuts | McMaster-Carr

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43 Products

Stainless Steel Hex Sealing Nuts

These nuts have good chemical resistance and may be mildly magnetic. They have a molded silicone seal that prevents leaks and seals out contaminants. They meet UL 50 for use on enclosures.

	Wd.	Ht.	Max. Pressure, psi	Seal Temp. Range, ° F	Specs. Met		Each
18-8 Stainless Steel



	6-32	5/16"	9/64"	6,000	-100 to 400	UL 50	91339A110	00000


	8-32	3/8"	5/32"	6,000	-100 to 400	UL 50	91339A115	0000
	10-24	3/8"	5/32"	6,000	-100 to 400	UL 50	91339A125	0000
	10-32	3/8"	5/32"	6,000	-100 to 400	UL 50	91339A120	0000
	1/4"-20	7/16"	7/32"	6,000	-100 to 400	UL 50	91339A130	0000
	1/4"-28	7/16"	7/32"	6,000	-100 to 400	UL 50	91339A135	0000
	5/16"-18	1/2"	17/64"	6,000	-100 to 400	UL 50	91339A140	0000
	5/16"-24	1/2"	17/64"	6,000	-100 to 400	UL 50	91339A145	0000
	3/8"-16	9/16"	21/64"	6,000	-100 to 400	UL 50	91339A150	0000
	3/8"-24	9/16"	21/64"	6,000	-100 to 400	UL 50	91339A155	0000
	7/16"-20	11/16"	3/8"	6,000	-100 to 400	UL 50	91339A160	0000


	1/2"-13	3/4"	27/64"	6,000	-100 to 400	UL 50	91339A165	0000
	1/2"-20	3/4"	27/64"	6,000	-100 to 400	UL 50	91339A170	0000
	5/8"-18	15/16"	35/64"	6,000	-100 to 400	UL 50	91339A175	0000

Metric Stainless Steel Hex Sealing Nuts

Made of stainless steel, these metric nuts have good chemical resistance and may be mildly magnetic. They have a silicone seal that prevents leaks and seals out contaminants.

	Wd., mm	Ht., mm	Max. Pressure, psi	Seal Temp. Range, ° F	Specs. Met		Each
18-8 Stainless Steel



	M3 × 0.5 mm	6	2.8	6,000	-100 to 400	UL 508A	90448A110	00000


	M4 × 0.7 mm	7	3.2	6,000	-100 to 400	UL 508A	90448A120	0000
	M5 × 0.8 mm	8	4	6,000	-100 to 400	UL 508A	90448A130	0000
	M6 × 1 mm	10	5	6,000	-100 to 400	UL 508A	90448A140	0000
	M8 × 1.25 mm	13	6.3	6,000	-100 to 400	UL 508A	90448A150	00000
	M10 × 1.5 mm	17	8	6,000	-100 to 400	UL 508A	90448A160	00000

Sanitary Cap Nuts

With extremely smooth sides and rounded edges, these nuts are free of crevices where bacteria can grow. Use them to cover and protect exposed threads while fastening parts together. Nuts are certified by EHEDG to meet sanitary design standards. They have a Buna-N seal on the base that keeps liquid, debris, and other contaminants off the threads. The seal is made with metal and chemical additives, so you can find it with a metal detector or X-ray machine if it falls into your line. Also known as acorn nuts, these have a domed head to create a finished look.

Stainless Steel

Image of Product. Front orientation. Cap Nuts. Sanitary Cap Nuts.

Highly Corrosion-Resistant 316 Stainless Steel—Won't corrode from frequent washdowns and can stand up to the harshest cleaners and detergents.

	Thread Dp.	Wd.	Ht.	Seal Material	Certification	Food Industry Std.		Each
Highly Corrosion-Resistant 316 Stainless Steel



	1/4"-20	1/4"	7/16"	21/64"	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A160	00000


	5/16"-18	9/32"	1/2"	25/64"	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A170	0000
	3/8"-16	5/16"	9/16"	15/32"	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A180	00000
	7/16"-14	21/64"	11/16"	33/64"	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A190	00000
	1/2"-13	11/32"	3/4"	35/64"	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A200	00000
	5/8"-11	7/16"	15/16"	43/64"	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A210	00000
	M6 × 1 mm	5.5 mm	10 mm	8 mm	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A110	00000
	M8 × 1.25 mm	6.5 mm	13 mm	10 mm	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A120	00000
	M10 × 1.5 mm	8 mm	16 mm	12 mm	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A130	00000
	M12 × 1.75 mm	9 mm	18 mm	14 mm	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A140	00000
	M16 × 2 mm	10.5 mm	24 mm	17 mm	Buna-N	EHEDG Certified	FDA Compliant 21 CFR 177.2600	97511A150	00000

Brass Hex Sealing Nuts

These nickel-plated brass sealing nuts have good resistance to chemicals and salt water. A nickel plating provides additional corrosion resistance and a decorative metallic finish. They have a silicone seal that prevents leaks and seals out contaminants. All meet UL 50 for use on enclosures. Nuts are nonmagnetic.

	Wd.	Ht.	Max. Pressure, psi	Seal Temp. Range, ° F	Specs. Met		Each
Nickel-Plated Brass



	6-32	1/2"	7/32"	6,000	-100 to 400	UL 50	90215A010	00000


	8-32	1/2"	7/32"	6,000	-100 to 400	UL 50	90215A410	0000
	10-24	1/2"	7/32"	6,000	-100 to 400	UL 50	90215A011	0000
	10-32	1/2"	7/32"	6,000	-100 to 400	UL 50	90215A411	0000
	1/4"-28	5/8"	7/32"	6,000	-100 to 400	UL 50	90215A429	0000
	3/8"-16	5/8"	7/32"	6,000	-100 to 400	UL 50	90215A031	0000
	3/8"-24	5/8"	7/32"	6,000	-100 to 400	UL 50	90215A431	0000

Sealing Cap Nuts

Keep liquid, gas, debris, and other contaminants from seeping into or out of machinery, with no need for a separate O-ring. These nuts are often used outdoors to protect enclosures and other equipment from harsh weather. They also withstand high pressure, so they are useful for sealing pneumatic pumps and pressure valves. Also known as acorn nuts, they conceal protruding screw threads while fastening parts together and have a smooth, rounded head for a finished look.

Stainless Steel

18-8 Stainless Steel—The choice for wet and outdoor environments, these nuts resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.

	Thread Dp.	Wd.	Ht.	Seal Material	Seal Temp. Range, ° F	Max. Pressure, psi		Each
18-8 Stainless Steel



	8-32	5/32"	5/16"	5/16"	Silicone Rubber	-80 to 400	1,200	90194A110	00000


	10-32	3/16"	3/8"	25/64"	Silicone Rubber	-80 to 400	1,200	90194A120	0000
	1/4"-20	1/4"	7/16"	15/32"	Silicone Rubber	-80 to 400	1,200	90194A130	0000
	3/8"-16	3/8"	5/8"	5/8"	Silicone Rubber	-80 to 400	1,200	90194A140	0000
	1/2"-13	1/2"	3/4"	13/16"	Silicone Rubber	-80 to 400	1,200	90194A150	0000