Square Neck Screws | McMaster-Carr

	System of Measurement System of Measurement

Inch

Metric

	Thread Size Thread Size

	Length Length

	Material Material

Steel

Stainless Steel

Bronze

	Finish Finish

Zinc Plated

Zinc Yellow-Chromate Plated

Black Oxide

Hot-Dipped Galvanized

Zinc-Aluminum Coated

	Threading Threading

	Fully Threaded
	Partially Threaded

	Head Type Head Type


Rounded	Flat

Oval

	Fastener Strength Grade/Class Fastener Strength Grade/Class


Grade 2	Grade 5

Grade 8	Class 8.8

	Head Diameter Head Diameter

	Neck Width Neck Width

	Head Height Head Height

	Neck Length Neck Length

	Thread Spacing Thread Spacing

Coarse

Fine

	Tensile Strength Tensile Strength

	Thread Type Thread Type

UNC

UNF

Metric

	Thread Pitch Thread Pitch

	Thread Fit Thread Fit

	Specifications Met Specifications Met

	Hardness Hardness

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	Minimum Thread Length Minimum Thread Length

993 Products

About Hex Head Screws and Bolts

Medium-Strength Grade 5 Steel
Square-Neck Carriage Bolts

Twice as strong as low-strength steel bolts, these bolts are suitable for fastening most machinery and equipment. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

Medium-Strength Metric Class 8.8
Steel Square-Neck Carriage Bolts

Choose these metric bolts for fastening most machinery and equipment. They are twice as strong as low-strength steel bolts. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

High-Strength Grade 8 Steel
Square-Neck Carriage Bolts

Made from Grade 8 steel, these bolts can be used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

Low-Strength Steel Square-Neck Carriage Bolts

About half the strength of medium-strength bolts, these Grade 2 bolts are for light duty fastening. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

18-8 Stainless Steel Square-Neck Carriage Bolts

These bolts have good chemical resistance. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

Super-Corrosion-Resistant 316 Stainless
Steel Square-Neck Carriage Bolts

More corrosion resistant than 18-8 stainless steel bolts, these bolts have excellent resistance to chemicals and salt water. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

Bronze Square-Neck Carriage Bolts

Bronze bolts are resistant to salt water, electrically conductive, and nonmagnetic. Carriage bolts have a smooth, rounded head for a finished look. The square neck keeps these bolts from turning when tightening a nut.

Square-Neck Flat Head Plow Bolts

Used on heavy equipment, such as plows, these bolts have a smooth head that's angled underneath to sit flush within countersunk holes. The square neck keeps these bolts from turning when tightening a nut.

Square-Neck Oval Head Plow Bolts

The thicker, domed head on these bolts provides greater wear resistance than flat head plow bolts. The underside of the head is angled to sit flush within countersunk holes for use on heavy equipment, such as plows. The square neck keeps these bolts from turning when tightening a nut.

Low-Strength Steel Square-Neck Elevator Bolts

About half the strength of medium-strength bolts, these Grade 2 bolts are for light duty fastening. These bolts are commonly used in tight spaces with moving parts, such as grain elevators and other belting systems, because the smooth, low-profile head provides a flush fit when installed. The square neck keeps these bolts from turning when tightening a nut.

Medium-Strength Grade 5 Steel
Square-Neck Elevator Bolts

Made from Grade 5 steel, these bolts are suitable for fastening most machinery and equipment. These bolts are commonly used in tight spaces with moving parts, such as grain elevators and other belting systems, because the smooth, low-profile head provides a flush fit when installed. The square neck keeps these bolts from turning when tightening a nut.

Stainless Steel Square-Neck Elevator Bolts

Made from stainless steel, these chemical-resistant bolts have a square neck that keeps them from turning when tightening a nut. They're commonly used in tight spaces with moving parts, such as grain elevators and other belting systems, because the smooth, low-profile head provides a flush fit when installed.

About Hex Head Screws and Bolts

Screws and Bolts

Medium-Strength Grade 5 SteelSquare-Neck Carriage Bolts

Medium-Strength Metric Class 8.8Steel Square-Neck Carriage Bolts

High-Strength Grade 8 SteelSquare-Neck Carriage Bolts