2"-12 Fasteners | McMaster-Carr

With tensile strengths from 110,000 psi to 125,000 psi, these rods are strong enough for most industrial applications, such as anchoring machinery and connecting pipe flanges. They are about twice as strong as low-strength steel rods. To avoid stripped threads during installation, make sure your nuts are also medium-strength steel.

Steel—Best for dry environments since moisture will cause these rods to rust.

	Hardness	Specs. Met		Each
Steel







	2"-12

	1	125,000	ASTM Grade B7	Rockwell C35	ASTM A193	000000000	000000


	3	125,000	ASTM Grade B7	Rockwell C35	ASTM A193	000000000	000000
	6	125,000	ASTM Grade B7	Rockwell C35	ASTM A193	000000000	000000

High-Strength Steel

With a tensile strength of 150,000 psi, these rods are strong enough to stabilize steel frameworks and structural supports, such as I-beams. They are about 25% stronger than medium-strength steel rods. To avoid stripped threads during installation, make sure your nuts are also high-strength steel.

Zinc-Yellow-Chromate-Plated Steel—The most common choice for areas with occasional exposure to moisture.

Steel—Best for dry environments since moisture will cause these rods to rust.

	Hardness	Specs. Met		Each
Zinc-Yellow-Chromate-Plated Steel







	2"-12

	3	150,000	ASTM Grade BD	Rockwell C33	ASTM A354 Grade BD	00000000	0000000


	Steel







					2"-12

					1	150,000	ASTM Grade BD	Rockwell C33	ASTM A354 Grade BD	000000000	000000


					2	150,000	ASTM Grade BD	Rockwell C33	ASTM A354 Grade BD	000000000	000000
					3	150,000	ASTM Grade BD	Rockwell C33	ASTM A354 Grade BD	000000000	000000
					6	150,000	ASTM Grade BD	Rockwell C33	ASTM A354 Grade BD	000000000	000000

Low-Strength Steel

With a tensile strength of 50,000 psi or 60,000 psi, these rods are often used to suspend light fixtures, cable trays, and conduit from ceilings. They're about half the strength of medium-strength steel rods. To avoid stripped threads during installation, make sure your nuts are also low-strength steel.

Steel—Best for dry environments since moisture will cause these rods to rust.

	Pkg. Qty.		Pkg.
Steel







	2"-12

	1	50,000	Rockwell B61	1	000000000	0000000


	2	50,000	Rockwell B61	1	000000000	000000
	3	50,000	Rockwell B61	1	000000000	000000
	6	50,000	Rockwell B61	1	000000000	000000

Hex Nuts

The most commonly used hex nuts, these are suitable for fastening most machinery and equipment.

Medium-Strength Steel

These Grade 5 or Class 8 nuts are your go-to for fastening most machinery and equipment. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	2"-12	3"	1 23/32"	SAE Grade 5	ASME B18.2.2	1	000000000	000000


	Steel



			2"-12	3"	1 23/32"	SAE Grade 5	ASME B18.2.2	1	000000000	00000

High-Strength Steel

Rated Grade 8, Grade C, or Class 10, these nuts are about 25% stronger than medium-strength steel nuts. They are commonly used to fasten components in valves, pumps, motors, and other high-stress applications. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Zinc-Yellow-Chromate-Plated Steel—With a more durable finish than clear zinc plating, these nuts are suitable for most wet and outdoor environments. However, they won't hold up to the harsh chemicals that stainless steel can.

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

Steel—Best for dry environments since moisture will cause these nuts to rust.

Zinc-Flake-Coated Steel—The most durable zinc coating, zinc flake is a multilayer finish that resists wear for long-term rust protection. Similar to zinc yellow-chromate, it won't hold up to harsh chemicals like stainless steel can.

	Wd.	Ht.	Fastener Strength Grade/Class	Pkg. Qty.		Pkg.
Zinc-Yellow-Chromate-Plated Steel



	2"-12	3"	1 23/32"	SAE Grade 8	1	000000000	000000


	Black-Oxide Steel



			2"-12	3"	1 23/32"	SAE Grade 8	1	000000000	00000


			Steel



					2"-12	3"	1 23/32"	SAE Grade 8	1	000000000	00000


					Zinc-Flake-Coated Steel



							2"-12	3"	1 23/32"	SAE Grade 8	1	000000000	00000

Low-Strength Steel

Rated Grade 2, Class 6, or lower, these nuts are about half as strong as medium-strength nuts. They are suitable for light duty fastening applications, such as securing access panels. Use them with screws that have a similar strength rating to avoid stripping threads during installation.

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Steel



	2"-12	3"	1 23/32"	SAE Grade 2	ASME B18.2.2	1	000000000	000000

Thin-Profile Hex Nuts

About half the height of standard-profile nuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against another hex nut to hold it in place.

Medium-Strength Steel

These Grade 5 or Class 04 nuts are your go-to for fastening most machinery and equipment. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

	Wd.	Ht.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	2"-12	3"	1 3/32"	SAE Grade 5	ASME B18.2.2	1	000000000	000000

High-Strength Steel

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Zinc-Yellow-Chromate-Plated Steel



	2"-12	3"	1 3/32"	SAE Grade 8	ASME B18.2.2	1	000000000	000000


	Steel



			2"-12	3"	1 3/32"	SAE Grade 8	ASME B18.2.2	1	000000000	00000

Low-Strength Steel

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Fastener Strength Grade/Class	Pkg. Qty.		Pkg.
Steel



	2"-12	3"	1 3/32"	SAE Grade 2	1	000000000	000000

Thin-Heavy-Profile Nylon-Insert Locknuts

About half the height of standard-profile locknuts and 10% wider, these fit in spaces with low clearance and handle heavier loads by distributing them over a larger area. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

High-Strength Steel

Rated Grade 8, Grade C, or Class 10, these locknuts are about 25% stronger than medium-strength steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Black-Phosphate-Coated Steel—The dark coating creates both a finished appearance and a barrier against rust that's comparable to zinc yellow-chromate plating.

	Wd.	Ht.	Fastener Strength Grade/Class	Insert Max. Temp., ° F		Each
Black-Phosphate-Coated Steel



	2"-12	3 1/8"	1 43/64"	ASTM Grade C	250	000000000	000000

Nylon-Insert Locknuts

Versatile yet economical, these are the most commonly used locknuts. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

High-Strength Steel

Steel—Best for dry environments since moisture will cause these nuts to rust.

	Wd.	Ht.	Fastener Strength Grade/Class	Insert Max. Temp., ° F	Pkg. Qty.		Pkg.
Zinc-Yellow-Chromate-Plated Steel



	2"-12	3 9/64"	2 13/32"	SAE Grade 8	220	1	000000000	000000


	Black-Oxide Steel



			2"-12	3 9/64"	2 13/32"	SAE Grade 8	220	1	000000000	00000


			Steel



					2"-12	3 9/64"	2 13/32"	SAE Grade 8	220	1	000000000	00000

Left-Hand-Thread Thin-Profile Hex Nuts

These nuts tighten when turned to the left. Use them with left-hand rods and screws to prevent counterclockwise-moving parts from loosening. About half the height of standard-profile nuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against another hex nut to hold it in place.

Medium-Strength Steel

These Grade 5 or Class 04 nuts are your go-to for fastening most machinery and equipment. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

	Wd.	Ht.	Fastener Strength Grade/Class	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	2"-12	3"	1 3/32"	SAE Grade 5	1	000000000	0000000

Low-Strength Steel

	Wd.	Ht.	Fastener Strength Grade/Class	Specs. Met	Pkg. Qty.		Pkg.
Black-Oxide Steel



	2"-12	3"	1 3/32"	SAE Grade 2	ASTM A108	1	000000000	000000

Corrosion-Resistant 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.

Highly Corrosion-Resistant 316 Stainless Steel—Superior to 18-8 stainless steel, these nuts won't degrade when exposed to harsh weather, salt water, and most chemicals.

	Wd.	Ht.	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel



	2"-12	3"	1 3/32"	ASME B18.2.2	1	000000000	000000


	Highly Corrosion-Resistant 316 Stainless Steel



			2"-12	3"	1 3/32"	—	1	000000000	00000

Locknuts for use with Cotter Pins

Use these locknuts to secure rotating parts subjected to mild vibration, such as the wheels on carts and hand trucks. They’re not recommended for use on parts exposed to high vibration because the pin can shear under prolonged stress. These nuts are reusable, but you'll need a new cotter pin (not included) with each use.

Low-Strength Steel

Rated Grade 2, Class 6, or lower, these locknuts are about half as strong as medium-strength steel nuts. Use them with screws that have a similar strength rating to avoid stripping threads during installation.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

	Wd.	Ht.	For Cotter Pin Dia.	Pkg. Qty.		Pkg.
Zinc-Plated Steel



	2"-12	3"	1 23/32"	3/8"	1	000000000	000000