DIYUK M6 (6mm) Hex Head Coach Screws DIN 571, Heavy Duty BZP Timber Fasteners and Lag Bolts, 40-120mm, 8 Lengths, Packs of 1-100

M6 hexagon head coach screws manufactured to DIN 571. Also known as lag screws, lag bolts or hex head wood screws, these heavy-duty fasteners use a hexagon head rather than a slotted or recessed drive, so they can be tightened with a standard spanner or socket for far higher torque than a screwdriver allows – useful wherever a fixing needs to be pulled up firmly and, if necessary, checked or re-tightened later.

The screws are manufactured from steel and finished with a bright zinc-plated (BZP) coating, giving general-purpose corrosion resistance.

The coarse, deep wood-screw thread is designed to bite directly into timber, generating high pull-out resistance without needing a nut on the far side – making these screws well suited to structural and semi-structural timber connections, as well as general joinery and assembly work. Used with a suitable wall plug, they can also be driven into brick, block or concrete, giving one fastener that covers both timber-to-timber and timber-to-masonry fixing.

Eight lengths cover these 6mm coach screws, so you can choose coach screws M6 x 40mm through to M6 x 120mm to suit different timber thicknesses and joint depths: short coach screws at 40mm and 50mm, mid lengths at 60mm, 70mm, 80mm and 90mm, and long wood screws for thicker timber, including 100mm wood screws and a 120mm length. Every size takes the same 10mm (0.39in) spanner or socket, so these hex screws are simple to install using standard tools.

Key Features

• Made to DIN 571, so diameter, head and thread geometry are consistent and standards-based across every length
• Hexagon head is driven with a 10mm (0.39in) spanner or socket rather than a screwdriver, allowing much higher installation torque and a more positive, controllable fixing
• Steel construction with a bright zinc-plated (BZP) finish, for general-purpose corrosion resistance
• Coarse, deep wood-screw thread bites directly into timber and develops high pull-out resistance without a nut needed on the reverse face
• Supplied in eight lengths from 40mm (1.57in) up to 120mm (4.72in), all in a single M6 (6mm) thread diameter, to suit different timber thicknesses and joint depths
• Thread length is 60% of the overall screw length on every size, giving a longer grip length as the screw gets longer
• Doubles as a masonry fixing when paired with a suitable wall plug, for fixing timber into brick, block or concrete as well as timber-to-timber
• Also known as a lag screw or lag bolt – a heavy-duty alternative to a coach bolt where fitting a nut and a full through-hole isn't practical

Specification

Thread, head and drive dimensions are as specified in DIN 571 for the M6 (6mm) thread size.

Typical Applications

• Timber-to-timber structural and semi-structural connections, such as joists, framing members and posts, where high pull-out resistance is needed but there is no access to fit a nut on the reverse side
• Outdoor timber structures such as garden decking frames and joists, pergolas and gazebos, and fence and gate construction, where a spanner-driven fixing gives a controlled, firm tightening in exposed structural timber
• Heavy joinery and assembly work, including workbenches and furniture, where a strong, spanner-tightened fixing is preferred over a screwdriver-driven wood screw
• Furniture making, interior fittings, and repair and renovation projects in timber
• Fixing timber battens, brackets or fixtures directly to brick, block or concrete, when the screw is used together with a suitable wall plug
• Any general DIY or trade job calling for a robust hexagon-head wood screw that can be tightened to a firm, positive torque, and checked or re-tightened later with the same spanner or socket

Installation Guidance

1. Drill a clearance hole through the first (fixing) timber, sized to the screw's 6mm (0.24in) shank, so this piece can pull down freely onto the timber beneath it
2. Drill a smaller pilot hole into the second (holding) timber, sized to roughly the thread's root diameter – use a smaller pilot in softer timbers and a slightly larger one in dense hardwoods, to prevent splitting
3. Drill both holes to at least the full length of the screw being fitted
4. Drive the screw home with a 10mm (0.39in) spanner or socket – the hexagon head allows significantly higher torque than a screwdriver-driven alternative
5. Fit a washer under the head where practical, to spread the load and stop the head sinking into softer timber
6. For fixing into masonry, insert a suitable wall plug into the pre-drilled hole before driving the screw home

Common Questions

Which length do I need?
Choose a length that passes through the timber you are fixing and leaves the threaded part in the timber beneath. Thread length is 60% of the screw length, listed for every size in the table above.

What spanner or socket fits?
A 10mm (0.39in) spanner or socket fits the head of every length of these hex head screws.

Do I need to pre-drill?
Yes: a clearance hole through the first timber and a smaller pilot hole into the second, as in the Installation Guidance above, to prevent splitting.

Can I fix them into brick or concrete?
Yes, with a suitable wall plug in brick, block or concrete.

Can I use them outdoors?
Yes. As exterior coach screws they suit outdoor timber structures such as decking frames, pergolas, gazebos, fences and gates; the manufacturer lists external structures exposed to weather conditions among their uses.

What pack sizes are available?
Packs of 1, 2, 5, 10, 20 or 100 screws in every length.