Nuts, Bolts & Washers

M6 roofing bolts with square or hex nuts are the most common choice for joining and fixing light and medium duty cable tray, with lengths such as M6 x 12 or M6 x 16 typical for coupler plates. Heavier systems may use M8 or M10. Always check the tray manufacturer's installation guide for the specified bolt size and finish.

A penny washer has a small hole and a large outside diameter, so it spreads the clamping force over a wider area. That makes it useful when bolting through thin sheet metal, plastic enclosures, timber or slotted holes, where a standard washer could pull through. They come in steel, galvanised and other finishes to match the bolt.

Hot dipped galvanised bolts are generally the better choice outdoors because the zinc coating is much thicker than standard zinc plating and resists rust for longer. They also match galvanised tray and steelwork, avoiding mixed metals. Zinc plated (BZP) fasteners are fine for dry indoor locations. For very aggressive environments, consider stainless steel.

Brass conducts well and does not rust, so brass nuts and washers are often used on earth terminals, bonding connections and terminal studs, where a clean, low-resistance contact matters. They are softer than steel, so tighten them carefully to avoid stripping threads, and follow the equipment manufacturer's torque guidance where it is given.

No, concrete screws cut their own thread into a drilled hole in concrete or masonry, so no plug or anchor is needed. Drill to the diameter and depth the manufacturer specifies, clean out the dust and drive the screw in. They can usually be removed and reused in some cases, but check the product guidance before reinstalling.

Use a spring washer or a nylon insert locknut, both of which help resist loosening on equipment subject to vibration such as fans, motors and plant room steelwork. Tighten to an appropriate torque rather than as hard as possible. For critical connections, follow the equipment manufacturer's instructions and check terminals during periodic inspection.

M6 roofing bolts with square or hex nuts are the most common choice for joining and fixing light and medium duty cable tray, with lengths such as M6 x 12 or M6 x 16 typical for coupler plates. Heavier systems may use M8 or M10. Always check the tray manufacturer's installation guide for the specified bolt size and finish.

A penny washer has a small hole and a large outside diameter, so it spreads the clamping force over a wider area. That makes it useful when bolting through thin sheet metal, plastic enclosures, timber or slotted holes, where a standard washer could pull through. They come in steel, galvanised and other finishes to match the bolt.

Hot dipped galvanised bolts are generally the better choice outdoors because the zinc coating is much thicker than standard zinc plating and resists rust for longer. They also match galvanised tray and steelwork, avoiding mixed metals. Zinc plated (BZP) fasteners are fine for dry indoor locations. For very aggressive environments, consider stainless steel.

Brass conducts well and does not rust, so brass nuts and washers are often used on earth terminals, bonding connections and terminal studs, where a clean, low-resistance contact matters. They are softer than steel, so tighten them carefully to avoid stripping threads, and follow the equipment manufacturer's torque guidance where it is given.

No, concrete screws cut their own thread into a drilled hole in concrete or masonry, so no plug or anchor is needed. Drill to the diameter and depth the manufacturer specifies, clean out the dust and drive the screw in. They can usually be removed and reused in some cases, but check the product guidance before reinstalling.

Use a spring washer or a nylon insert locknut, both of which help resist loosening on equipment subject to vibration such as fans, motors and plant room steelwork. Tighten to an appropriate torque rather than as hard as possible. For critical connections, follow the equipment manufacturer's instructions and check terminals during periodic inspection.