Buying fasteners in bulk is one of the most straightforward ways to reduce costs on construction, fabrication, and maintenance projects. But knowing how many to order, which size to buy in bulk, and how to store them properly makes the difference between a smooth job and a frustrating one.
This guide covers everything you need to know about buying metric fasteners in quantity — whether you're a sole trader stocking your van or a site manager ordering for a large project.
Why buy fasteners in bulk?
The unit cost of metric fasteners drops significantly when you buy in packs of 100 rather than individually. For the fasteners you use regularly — M8 hex nuts, M10 washers, M6 bolt sets — buying a box of 100 typically costs 40–60% less per unit than buying in smaller quantities. Over the course of a year's work, this adds up to a meaningful saving.
There's also the practical benefit of always having what you need on hand. Running out of M10 nuts mid-job and having to make a trip to the merchants costs time that quickly outweighs the cost of a box of 100.
Which fasteners are worth buying in bulk?
The fasteners most worth buying in bulk are the ones you use most regularly and that have a long shelf life:
- M8 and M10 hex nuts (BZP) — used in almost every fabrication and construction project. Buy a box of 100 of each and replenish when you're down to the last 20 or so.
- M8 and M10 flat washers — used with nearly every nut and bolt. Washers are easy to lose and cheap to buy in bulk.
- M8 x 25mm and M10 x 30mm bolt/nut/washer sets (BZP) — if you do regular assembly or construction work, pre-matched sets save time and ensure you never have mismatched components.
- Spring washers — if you do any mechanical or automotive work, keep a box of M8 and M10 spring washers in stock. You'll always need them.
- M10 threaded rod cut studs — for any regular fixing or mounting work, having a stock of cut studs in common lengths (100mm, 150mm, 200mm) is much more convenient than cutting from a 1 metre rod each time.
How to store fasteners properly
Fasteners are cheap but they become useless if they corrode or get mixed up. A few simple steps keep your stock in good order:
- Keep BZP fasteners dry. Zinc plating is not waterproof. Store BZP fasteners in a dry environment — a sealed bin, drawer cabinet, or storage box. Don't leave them in the back of an open van for weeks.
- Label everything. Mixed-up fasteners waste more time than any saving from buying in bulk. Use a label maker or masking tape labels on each compartment or box.
- Separate finishes. Keep BZP, HDG, and stainless fasteners in separate containers. Mixing them up on a job — especially in outdoor or structural applications — can cause accelerated corrosion.
- First in, first out. Use older stock before newer stock to prevent any fasteners sitting unused long enough to deteriorate.
Calculating how many you need
A useful rule of thumb for construction and fabrication projects:
- Allow 10–15% extra on your estimated quantity for waste, dropped fixings, and adjustments.
- For box sets (bolt/nut/washer), count your fixing points and order that number plus 15%.
- For threaded rod and nuts used in suspension or structural applications, count the number of hanging/fixing points and multiply by 2 (one nut each side) plus your contingency.
Free delivery on orders over £60
At Northern Fasteners, orders over £60 qualify for free UK delivery. Ordering in bulk almost always gets you over this threshold, so the savings on unit cost are compounded by savings on delivery. Browse our full range and build your stock order below.
