M3.5 Couplings | McMaster-Carr

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

REACH Compliant

	Nut Type Nut Type


Coupling	Hex

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163 Products

Fasteners

Metric Low-Strength Steel Coupling Nuts

For light duty applications, choose these metric-sized coupling nuts.

Plastic Coupling Nuts

Plastic coupling nuts are chemical resistant, nonconductive, and lightweight.

Steel Extra-Long Coupling Nuts

Known for their strength, steel coupling nuts are available with a corrosion-resistant finish.

Metric-to-Metric Male-Female Hex Thread Adapters

In addition to joining male- and female-threaded parts, these adapters can increase or decrease metric thread sizes and change the thread pitch.

Inch-to-Metric Male-Female Hex Thread Adapters

Change inch threads to metric with these adapters, or swap metric threads for inch. An external hex lets you tighten or loosen them with a wrench.

Metric-to-Metric Female Hex Thread Adapters

Increase or decrease metric thread size from one male-threaded part to another. Commonly used to connect two differently sized threaded rods, they have a hex-shaped body, so you can tighten them with a standard wrench.

Inch-to-Metric Female Hex Thread Adapters

Adapt threaded rods from inch to metric. These adapters connect two male-threaded fasteners, so you can change the gender of a mating part or increase or decrease its thread size. The hex-shaped body fits into the head of a standard wrench.

Inch-to-Metric Male Hex Thread Adapters

One side inch, one side metric, and a hex in the middle—these handy fasteners connect two female-threaded parts, such as coupling nuts, adapting from inch threads to metric. Tighten with a standard wrench.