Thunderbolts – Multi Purpose Fixing Bolt – Countersunk Torx Head

Countersunk Torx Thunderbolts are what most people picture when someone says ‘masonry bolt’, and for good reason. They’re a self-tapping anchor that cuts its own thread into concrete, brick, block and natural stone, so the wall itself ends up acting as the nut. No expanding sleeves, no resin, no waiting about. Drill, clear the dust, drive it home.

This version has a countersunk head with a Torx drive. The flat head pulls down flush with the surface, which matters when you’re fixing timber battens, door frames, metal brackets or anything else that shouldn’t have a lump sticking out of it. The Torx recess grips the driver bit far better than a slotted or Phillips head, so you get more torque without the bit skipping out and chewing the head. If you’ve ever rounded off a screw head forty minutes into a job, you’ll know why that’s a good thing.

Why Countersunk Torx Thunderbolts Suit So Many Jobs

The thread profile is designed to cut cleanly into the substrate rather than force it apart. That means you can fix closer to an edge or closer to the next fixing than you could with an expansion anchor, without cracking the brick or blowing out the corner of a block. Embedment depth is flexible too, so you can adjust to suit the load and the material.

Because the thread bites into the base material rather than relying on expansion, the bolt can be backed out and removed when the job is done. That makes them sensible for temporary fixings, formwork, hoarding, scaffolding boards or anything you might need to take down again. They’re equally at home on permanent work, such as fixing timber frames, sole plates, fascia brackets, window and door frames, and light steel sections.

Sizes and Pack Options

We stock these in 5mm and 6mm diameters. The 5mm bolts run from 30mm up to 100mm, and the 6mm range goes from 50mm up to 150mm. Longer lengths are there for fixing through thicker timber or packers, where you still need a decent amount of thread in the masonry. Boxes come in 100 or 200 depending on size, and the bulk discounts are well worth a look if you’re doing a full day of fixing rather than one bracket.

Use a standard masonry drill bit matched to the diameter of the bolt. There’s no special hardware to buy, no setting tool, and no faff. A decent hammer drill and an impact driver or drill driver with the correct Torx bit is all you need. Drill the hole slightly deeper than the bolt length to leave room for dust, and clean it out properly before driving.

For anyone fixing into mixed masonry, they’re a reliable all-rounder. If you’re fixing into something soft like aircrete or hollow block, check the manufacturer’s guidance on drilling and torque first, as these materials can strip if you overdo it.