Nuts, Bolts and Washers
Trade-quantity nuts, bolts and washers for ductwork installation — the M8 and M10 fixings that every ventilation first-fix runs on. Most lines are supplied in boxes of 100, so you are stocked for the whole job rather than buying blister packs from a merchant.
The range covers:
- Channel nuts (plain) — M8 and M10, for use with slotted channel
- Wedge nuts — M8 and M10
- Hex head full nuts — M8 and M10
- Hex head set screws — M8 × 25mm and M10 × 25mm
- Penny washers — M8 × 25mm and M10 × 25mm
- Back plates — male M10 × 40mm and female M8/M10 dual thread
- Tek screws — box of 1,000 complete with drill bit
Pair them with threaded rod and duct clips to hang spiral ducting quickly and securely. Stocked items ordered by 3pm ship next day, and UK mainland delivery is free on orders over £400 ex VAT.
Showing all 13 results
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Back Plate Female – M8/M10 Dual Thread
£1.00 + VAT Add to basket -
Channel Nut (Plain) – M10 – Box of 100
£13.30 + VAT Add to basket -
Channel Nut (Plain) – M8 – Box of 100
£11.10 + VAT Add to basket -
Hex Head Full Nuts – M10 – Box of 100
£4.88 + VAT Add to basket -
Hex Head Full Nuts – M8 – Box of 100
£4.88 + VAT Add to basket -
Tek Screws (Box of 1,000) c/w Drill Bit
£13.25 + VAT Add to basket -
Wedge Nuts – M10 – Box of 100
£23.65 + VAT Add to basket -
Wedge Nuts – M8 – Box of 100
£23.65 + VAT Add to basket -
Hex Head Set Screws – M10 x 25mm – Box of 100
£8.45 + VAT Add to basket -
Hex Head Set Screws – M8 x 25mm – Box of 100
£4.88 + VAT Add to basket -
Penny Washer – M10 x 25mm – Box of 100
£2.70 + VAT Add to basket -
Penny Washers – M8 x 25mm – Box of 100
£2.70 + VAT Add to basket -
Back Plate Male – M10 x 40mm
£1.00 + VAT Add to basket
Ductwork Fasteners
Reliable fixings are fundamental to a safe, airtight, and durable ductwork installation. Alpha Air supplies the complete range of nuts, bolts, washers, screws, and rivets used by ventilation engineers and sheet-metal workers throughout the UK.
Our Fastener Range
Flange Bolts and Nuts
M6 and M8 hex-head bolts with matching flange nuts for assembling rectangular ductwork flanges. Supplied in zinc-plated mild steel for corrosion resistance. Available in various lengths to suit different flange thicknesses and gasket arrangements.
Self-Tapping Screws (Tek Screws)
Self-drilling, self-tapping screws that pierce and thread into galvanised steel duct walls without the need for a pilot hole. The most common fixing for securing spiral duct joints, attaching brackets, and fixing accessories. We stock 4.2×13 mm (No.8 × ½″) hex-head tek screws in bulk packs — the industry-standard size for ductwork.
Pop Rivets (Blind Rivets)
Aluminium or steel rivets for permanent fastening where a screw head would protrude into the airstream or where a flush exterior finish is needed. Applied with a standard rivet gun from one side of the joint. Common sizes are 4.0 mm and 4.8 mm diameter.
Washers
Flat washers, spring washers, and penny washers in zinc-plated steel. Used under bolt heads and nuts to distribute load, prevent loosening from vibration, and protect the galvanised duct surface from damage during tightening.
Bulk and Trade Packs
We sell fasteners in practical quantities for trade users — boxes of 100, 200, 500, and 1000. Ordering in bulk alongside your ductwork and fittings saves time and money compared to buying small packs from a general hardware supplier.
Corrosion Protection
All our standard fasteners are zinc-plated to match the galvanised duct they are securing. For stainless steel ductwork installations or marine/corrosive environments, we can supply A2 (304) or A4 (316) stainless steel fasteners to prevent bimetallic corrosion at the fixing point.
Why Choose Alpha Air?
Order your fasteners alongside your ducting and fittings for a complete delivery in one shipment. Alpha Air has been supplying the UK ventilation trade — we understand what installers need and stock it in the right quantities. Free delivery on orders over £400. Call 0116 246 0031.
Frequently Asked Questions
What screws should I use for spiral duct joints?
Use 4.2x13mm (No.8 x 1/2 inch) hex-head self-tapping tek screws. These are the industry standard for securing spiral duct joints. Place two or three screws evenly around each joint after applying sealant and before taping. We sell them in bulk packs of 100 or more.
Should I use screws or rivets on ductwork?
Self-tapping screws are faster to install and can be removed if a joint needs to be dismantled. Pop rivets provide a flush finish and are better for joints that will never be taken apart. Most installers use screws for general ductwork and rivets for visible or internal airstream surfaces where screw heads would cause turbulence.
What size bolts are used on rectangular duct flanges?
M6 or M8 hex-head bolts with flanged nuts are standard for rectangular duct flange connections. M8 is the more common size for commercial ductwork. Space bolts at approximately 150mm centres around the flange perimeter for an airtight seal over the gasket.