Showing all 11 results
Showing all 11 results
SD Aluminium stocks a full range of bolts, nuts, anchors and washers for construction, engineering, fencing and DIY across New Zealand. From coach bolts and engineering bolts to through bolts, coach screws and masonry anchors, every fastener is supplied in grades built for NZ conditions, including 316 stainless steel for coastal and marine sites and galvanised steel for general structural work. Whether you are bolting a deck, fixing a fence post, assembling a structure or anchoring into concrete, you will find the right bolt here.
Coach bolts, also called carriage bolts, have a smooth domed head and a square neck that grips into timber so the bolt will not spin as you tighten the nut. They are the standard choice for timber to timber and timber to steel fixing on decks, fences, pergolas and retaining walls. Our coach bolts and nuts are supplied in 316 stainless steel for long term outdoor and coastal use.
Engineering bolts, also known as hex bolts or machine bolts, have a hex head for socket or spanner driving and a fully rated thread for structural and mechanical fixing. They suit steel framing, brackets, plant and machinery, and any joint that needs a precise, high strength clamp. Available in 316 stainless steel for corrosion resistance.
Through bolts pass right through the fixture and the base material and clamp with a nut and washer on the far side, giving a strong, serviceable joint. For fixing into concrete and masonry, masonry anchors and hammer drive anchors hold fixtures, brackets and structural components directly in solid base material. Through bolts are supplied with nuts and washers in 316 stainless steel.
Coach screws are heavy duty hex head wood screws that drive into timber without a nut, for fast structural fixing of brackets, joists, posts and heavy fixtures. We stock hex head coach screws in galvanised steel and self tapping coach screws in stainless steel.
Complete the fixing with square and round washers in galvanised steel, 316 stainless steel and EPDM rubber sealing washers for weather tight roofing and cladding fixings. We also supply aluminium bolts, nuts and fasteners for lightweight, rust free fixing where steel is not suitable.
What is the difference between a coach bolt and a carriage bolt?
They are the same fastener. Coach bolt is the common NZ term and carriage bolt the American term for the domed head bolt with a square neck that bites into timber so it cannot spin while you tighten the nut.
Can I use coach bolts for decking and fence posts?
Yes. Coach bolts are a standard fixing for decks, fence posts, pergolas and retaining walls. For outdoor and coastal use, choose 316 stainless steel so the bolt does not rust and stain the timber.
How do I bolt into concrete or brick?
Use a masonry anchor or a through bolt sized for the load. Drill a pilot hole, clear the dust, then fit the anchor or drive the masonry screw. For a self tapping option, see our masonry anchor concrete screws.
316 stainless or galvanised: which bolt do I need?
Choose 316 stainless steel for coastal sites, marine environments and anywhere exposed to weather long term. Galvanised steel is fine for general structural and sheltered outdoor fixing at a lower cost. For the full comparison, read our stainless steel grades guide.
What size bolt do I need?
Match the diameter to the load and the length to the combined thickness of the materials plus enough thread for the nut. If you are not sure, send the job details and the team will recommend the right size and grade.
Need help choosing? Read our guides on 304 vs 316 stainless steel and choosing the right masonry anchor, browse the wider screws and fasteners range, or contact the SD Aluminium team for trade pricing and bulk orders.
