Square/Square Holding Down Bolt & Nut (8.8 HT)

Our Square/Square Holding Down Bolts & Nuts are designed for heavy-duty anchoring in groundworks, civil engineering and structural steel projects. The square shank locks into a square plate washer to prevent rotation during tightening, ensuring a secure and stable foundation connection.

Available in sizes M16–M30 and lengths up to 600 mm, these bolts are manufactured from grade 8.8 high-tensile steel for long-lasting performance.

Key Features

• Grade 8.8 high-tensile steel to BS 7419.

• Square/square design prevents rotation under load.

• Supplied with nut, compatible with square-hole plate washers.

• Sizes M16, M20, M24 & M30 in multiple lengths.

• Ideal for fixing base plates, beams and machinery.

• Galvanised finish available – contact us for details.

• Next-day delivery across the UK.

FAQ
What does square/square mean?
The bolt has a square neck that fits a square hole washer, preventing movement during tightening.

What applications are these bolts suited to?
They’re used in groundworks, structural steel erection, and machinery installations where secure fixing is critical.

Can I order galvanised bolts?
Yes, galvanised options are available. Call 020 8079 7719 for pricing.

Are these bolts sold with washers?
This listing is for bolt and nut only, plate washers and cones can be ordered separately or as part of a full set.