Square Head Bolts | McMaster-Carr

About half the strength of medium-strength screws, these screws are for light duty fastening applications, such as securing access panels. Large flat sides make these screws easy to grip with a wrench and keep them from rotating in square holes.

Medium-Strength Grade 5
Steel Square Head Screws

Made from Grade 5 steel, these screws are suitable for fastening most machinery and equipment. Large flat sides make these screws easy to grip with a wrench and keep them from rotating in square holes.

High-Strength Grade 8
Steel Square Head Screws

Made from Grade 8 steel, these screws can be used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems. Large flat sides make these screws easy to grip with a wrench and keep them from rotating in square holes.

Steel Square-Head
Cup-Point Set Screws

Use these steel set screws for light duty holding.

18-8 Stainless Steel Square-Head
Cup-Point Set Screws

These set screws have good chemical resistance.

Super-Corrosion-Resistant 316
Stainless Steel Square-Head
Cup-Point Set Screws

More corrosion resistant than 18-8 stainless steel set screws, these have excellent resistance to chemicals and salt water.

Alloy Steel Square-Head
Cup-Point Set Screws

Alloy steel set screws dig into hard surfaces for a secure hold.

Metric Square-Head
Extended-Tip Set Screws

These metric screws have a square head, so you can turn them by hand or use a wrench for more torque. Also known as half dog-point set screws, they have a protruding tip that locks within a mating hole or slot to keep parts aligned.

Square-Head
Extended-Tip Set Screws

Use the square head to turn these screws by hand, or use a wrench when you need more torque. Also known as half dog-point set screws, they have a protruding tip that locks within a mating hole or slot to keep parts aligned.