Screws & Bolts, Aluminum

Bolting aluminum to aluminum

The clearest case for an aluminum bolt is joining aluminum, because a same-metal joint has no galvanic difference to drive corrosion. Drop a steel or stainless bolt into an aluminum part in a damp environment and the aluminum around it starts to corrode; use an aluminum bolt and that couple disappears. That makes aluminum screws and bolts the natural choice for aluminum frames, extrusions, panels, and enclosures, especially outdoors or anywhere moisture is present. The material's other properties come along for free: the light weight matters in transport and portable equipment, the non-magnetic behaviour suits instruments and electronics, and the non-sparking property suits work near flammable atmospheres. The trade to design around is strength. Aluminum is softer and weaker than steel, so these are not high-clamp structural bolts, and the threads strip more easily if overtightened, so correct torque matters more than with steel. Where the load is light to moderate and the base metal is aluminum, they are the right fastener.

Why choose aluminum screws and bolts

• Match aluminum parts to avoid galvanic corrosion
• Lightweight, roughly a third the weight of steel
• Corrosion resistant through aluminum's oxide layer
• Non-magnetic and non-sparking for sensitive and hazardous work
• Hex cap screws for wrench-driven clamping

Common applications

• Fastening aluminum frames and extrusions
• Aluminum panels and enclosures
• Weight-critical transport and portable equipment
• Non-magnetic electronics and instrumentation
• Non-sparking work near flammable atmospheres
• Light to moderate load joints in aluminum

Aluminum Screw & Bolt FAQs

Why bolt aluminum with aluminum?

A same-metal joint has no galvanic difference, so there is no preferential corrosion. A steel or stainless bolt in aluminum can corrode the aluminum around it in moisture; an aluminum bolt avoids that couple.

Are aluminum bolts strong enough for structural work?

They are softer and weaker than steel, so they suit light and moderate loads, not high-strength structural connections. Where high clamp load is needed, isolated stainless may be chosen instead.

Will the threads strip?

Aluminum is soft, so threads strip more easily if overtightened. Use correct torque, avoid overdriving, and take care with tool speed to protect the threads.

Do these need anti-seize?

Aluminum can gall and seize, especially aluminum-on-aluminum threads, so an anti-seize suited to aluminum helps assembly and later removal. It also eases reaching correct torque without galling.

Can I use an aluminum bolt to hold steel parts?

Not advisably. An aluminum bolt holding steel or stainless is a small anode against a large cathode and corrodes quickly. Use aluminum bolts in aluminum, not to hold more noble metals.

Are they non-magnetic?

Yes, aluminum is non-magnetic, which suits instruments, electronics, and any assembly where a magnetic fastener would interfere. It is also non-sparking for hazardous atmospheres.