BS 7419 Holding-Down Bolts
BS 7419 holding-down bolts secure steel structures to their foundations. The standard covers square-head square-neck and hexagon-head forms, product grade C, M16 to M64; our data covers M16 to M48, with other requirements quoted on request.
Also known as: square bolt, square square, coach bolt square, square head coach bolt, square neck bolt, holding down bolt, holding-down bolt, foundation bolt, HD bolt, square head bolt.
BS 7419 dimensions
| Diameter | Width of square head | Depth of square head | Standard thread length |
|---|---|---|---|
| M16 | 24mm | 10mm | 116mm |
| M20 | 30mm | 12.5mm | 120mm |
| M22 | 32mm | 14mm | 122mm |
| M24 | 36mm | 15mm | 124mm |
| M27 | 41mm | 17mm | 127mm |
| M30 | 46mm | 18.7mm | 130mm |
| M33 | 50mm | 21mm | 133mm |
| M36 | 55mm | 22.5mm | 136mm |
| M39 | 60mm | 25mm | 139mm |
| M42 | 65mm | 26mm | 142mm |
| M45 | 70mm | 28mm | 145mm |
| M48 | 75mm | 30mm | 148mm |
What is a BS 7419 holding-down bolt?
BS 7419 is the British Standard specification for holding-down bolts — product grade C bolts used to secure steel structures to their foundations and in similar applications. The standard covers metric threads from M16 up to and including M64.
What head styles does BS 7419 cover?
The standard specifies bolts with square heads and square necks, in two neck forms, along with hexagon-head bolts. Other holding-down patterns fall outside the standard, although we supply specials made to drawing.
What sizes of BS 7419 holding-down bolts can you supply?
We supply BS 7419 holding-down bolts across a wide range of the standard's metric sizes in a choice of grades and finishes. Send us your requirement and we can identify the appropriate product.
Need BS 7419 in a non-standard size or material?
Send us your drawing — specials quoted within 24 hours.