Harfington Discount Codes & Vouchers

Harfington is an online hardware and components shop: fasteners, tubing and fittings, bearings and power transmission parts, electrical and lighting components, hand tools and workshop consumables.

A parts bin rather than a shop window

The catalogue is organised the way a supplier's is, by category and then by specification: screws and bolts by thread and length, hose and tubing by bore and material, bearings by bore and outside diameter, belts and pulleys by pitch. Alongside those sit lab and scientific bits, abrasives and polishing supplies, and a car and motorcycle section. It is aimed at people repairing and building things rather than at browsers, and the way to use it is to search on the exact measurement rather than to wander through categories.

Measure the part, do not guess the size

The single biggest cause of a wasted order in this category is ordering the wrong size, and it is avoidable. Use callipers rather than a tape measure for anything under a few centimetres. For threaded fasteners you need diameter, thread pitch and length, and metric and imperial threads can look identical while being incompatible — a thread gauge costs very little and saves far more. For hose and tubing, check whether the figure quoted is the inside or outside diameter, because both are used. For bearings, the three numbers are bore, outside diameter and width, and all three must match.

Bulk packs, and when they are false economy

Much of the stock is sold in multiples, which is genuinely cheaper per piece for anything you use repeatedly — common screw sizes, cable ties, heat-shrink, washers. It is false economy for anything specific to one job, where you end up storing ninety-five of something you will never need again. A reasonable rule: buy in bulk the things you have already run out of at least once. Buying an assortment box of mixed sizes is the cheap way to find out which sizes you actually use.

Materials, ratings and the parts where it matters

Read the material specification rather than the photograph. Stainless grades differ in how they handle salt and damp; plated steel rusts where it is cut; nylon and PTFE tolerate very different temperatures. Where a part carries a load or pressure — lifting hardware, hose fittings, electrical connectors — the rating is the specification that counts, and a part without a stated rating should not be assumed to have one. Anything that forms part of a building's fixed wiring, a gas installation or a vehicle's braking or steering is work for a qualified person.