9Pcs Inch Magnetic Nut Drivers Set

Imported machinery, American and older British equipment, air conditioning plant, generators, compressors, and a good deal of imported roofing and cladding hardware all use inch hex heads. A metric set will get close on some of them and close is exactly the problem: a 10mm socket on a 3/8" head fits loosely enough to round it, and a 13mm on a 1/2" head does the same. The heads on self-drilling screws are thin-walled and round out very readily, so a near-fit is a damaged fastener rather than a compromise.

The quantities in the set reflect real use rather than a tidy grid: two 1/4", three 5/16", two 3/8", one 7/16" and one 1/2". Five-sixteenths is the commonest imperial self-drilling screw head, which is why there are three of them — these are consumables that wear at the corners and get lost, and the pack is weighted towards the size that goes first.

The magnet holds the screw on the driver for one-handed placing, which on cladding, roofing, ducting and overhead work is what makes power driving practical at all.

The material is Cr-V steel, hardened and tempered — chromium for the hardness and wear resistance that keeps the internal hex corners sharp, vanadium for the toughness that stops a thin-walled socket splitting.

The buyers are HVAC and refrigeration installers, roofing and cladding contractors working with imported systems, generator and compressor engineers, machinery importers and installers, sheet metal fabricators, and hardware dealers supplying the AC and plant trades.

Two habits. Seat the socket fully on the head before applying power. And keep the magnets clean of drill swarf, since self-drilling screws throw filings that collect in the socket and stop the next screw sitting flat — the usual cause of slipping. Ask us on WhatsApp for a price.