Through bolt anchors are designed for use in concrete or dense natural stone with a strength greater than 20N/mm2 and are probably the most widely used fixing bolt in today's market. The throughbolt requires a hole in concrete the same diameter as the bolt, thus allowing the hole to be drilled through the fixture avoiding lengthy marking out procedures. Throughbolts are a versatile, cost–effective anchor combining ease of installation with good load carrying capabilities.
These throughbolts are normally supplied in zinc and yellow passivated (ZYP) finish and preassembled with the nuts and washer. They are fully threaded allowing for a more flexible use of the anchor with different fixture thicknesses. With throughbolts the drill size is the same as the anchor diameter i.e. M12 requires a 12mm diameter drill hole. The fixture thickness is important when using throughbolts, you should not exceed the maximum fixture thickness for the anchor length.
ZYP finish throughbolts are used mainly for internal and protected applications. We would recommend using our galvanised or stainless steel versions in external or high corrosion environments.
When selecting any fixing bolts the following factors must be considered.
- Thickness of fixture including any packing
- Non–structural screed must be included in the fixture thickness
- Compressive strength of concrete
- Distance from any edge
- Centre to centre distance of anchors
If you require further technical information please contact our technical support team. If you have safety critical applications we can also offer higher performance anchors.