M18 Screws | McMaster-Carr

Choose these metric screws for high-strength fastening. Often used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems, these screws are at least 25% stronger than medium-strength steel screws.

Medium-Strength Metric Class
8.8 Steel Hex Head Screws

Choose these metric screws for fastening most machinery and equipment. They are twice as strong as low-strength steel screws.

18-8 Stainless Steel
Hex Head Screws

Use these general purpose 18-8 stainless steel screws for a variety of fastening applications. They have good chemical resistance.

Metric Alloy Steel Hex
Drive Flat Head Screws

Metric Alloy Steel
Cup-Point Set Screws

These alloy steel set screws have a thin edge that digs into hard surfaces for a secure hold. They're available in metric sizes.

Threaded Rods

Metric Medium-Strength Steel
Threaded Rods—Grade B7

These metric Grade B7 threaded rods meet the pressure and temperature requirements of ASTM A193 and are often used to secure pressure tanks, valves, and flanges.

Medium-Strength Steel
Threaded Rods—Class 8.8

An economical alternative to Grade B7 and Grade B16 threaded rods, these metric Class 8.8 rods are suitable for fastening most machinery and equipment.

Metric Fine-Thread Low-Strength
Steel Threaded Rods

About half the strength of medium-strength steel threaded rods, use these metric fine-thread rods for light duty hanging, mounting, and fastening.

Metric Low-Strength
Steel Threaded Rods

These metric threaded rods are about half the strength of medium-strength steel threaded rods for light duty hanging, mounting, and fastening.

Metric High-Strength Steel
Threaded Rods—Class 10.9

These Class 10.9 steel threaded rods are about 25% stronger than medium-strength steel rods.

Metric 18-8 Stainless
Steel Threaded Rods

Available in metric sizes, these 18-8 stainless steel threaded rods have good chemical resistance.

Metric Ball Screws and Nuts

Internal ball bearings provide smooth low-friction travel in applications that require high speeds, accurate positioning, and repeatable movement. Also known as single-start metric ball screws and nuts, these have a single thread that runs the length of the screw.