Our Most Popular Holding Down Bolts
Holding down bolts, also known as foundation bolts, structure anchor bolts, ground bolts and steel frame anchor bolts, are used in construction to secure steel frames to concrete pads or column base plates to concrete flooring.
This connection is made by assembling square/square bolts, nuts, round washers, square plate washers and waxed cardboard cones (see image below) and casting this group of components in pockets into the concrete pad. The square hole plate washers prevent rotation and pulling out of the holding down bolt when tightening.
How are holding down bolts used?
Commonly, four foundation bolts are used in each baseplate. Concrete will be poured around the waxed cardboard cones to allow lateral movement of the bolts, which will make lining up of the above ground structure much easier. Once the steel frame is set in place, the foundation bolts will be grouted in. Vertical adjustments can also be done by using packers and shims between the baseplate and the concrete.
What does Speedy Fixings offer?
To simplify the buying process, we have put together an assembled package of holding down bolts, comprising the most popular sizes of square/square foundation bolts, square hole plate washers and tapered waxed cones.
Our standard holding down bolts conform to BS 7419 and are supplied in grade 8.8 high tensile steel. We can also supply holding down bolts in galvanised steel and stainless steel in sizes up to M72, plus we can manufacture bespoke bolt cluster ‘cages’ to the customer’s specifications.