Anchor Bolts

Handan Hengmai Fasteners Manufacturing Co., Ltd. is one of the most reliable manufacturers and suppliers of anchor bolts in China. As we have world-leading production equipment and strong manufacturing capabilities, we warmly welcome you to buy bulk high quality anchor bolts for sale here from our factory. Customized orders are welcome.

Anchor bolts are the part of a job that nobody looks at once the machine is running, but everybody notices when something goes wrong. If the bolt is too short, the thread does not clear the nut. If the hook is bent the wrong way, it pulls straight out of the concrete under load. If the wrong coating is used on an outdoor foundation, it starts rusting before the first year is over. We have seen all three of these over the years, usually after the customer has already poured the concrete.

We make anchor bolts here in Yongnian, in L type, J type and straight rod type, to GB799, DIN529, or to whatever drawing you send us. Carbon steel is the normal choice, but we also run 304 and 316 stainless when the site is near the coast or the soil is aggressive. Most of our orders go to machinery installers, steel structure contractors and power station projects in the Middle East, Africa and Southeast Asia. They keep ordering from us because the threads are clean and the bends are consistent, so the bolts drop into the foundation holes without anyone having to fight them.

On the shape: L type is the common one for general equipment. J type gives a bit more grip in poor quality concrete because the curved tail resists pull out better. Straight rod type is used where the bolt is welded to a plate or embedded in a pre cast element. If you are not sure which one suits your base, tell us the load and the concrete grade and we will suggest something.

How deep should the bolt go into the concrete? There is no single number that fits everything. The old rule of thumb is fifteen to twenty five times the bolt diameter, so an M20 goes down somewhere between 300 and 500 mm. But the real answer depends on the concrete grade and the load. If you are working to a drawing from your engineer, follow the drawing. If you are not, send us the equipment weight and we will give you a rough suggestion, though we always tell people to confirm with their structural engineer before pouring. We would rather answer an extra question than hear about a machine that shifted after six months.

How much thread should stick out above the concrete? Enough to take the nut, the washer, and a few spare threads. A common mistake is ordering the thread length exactly the thickness of the nut and washer, which leaves nothing to torque against. We normally add thirty to fifty millimetres of spare thread on top of the nut and washer thickness, and we mark the drawing so the customer can see exactly where the thread starts and where it ends.

Electro galvanized or hot dip galvanized? For anything buried in the ground or sitting outdoors, use hot dip galvanized. The coating is thicker and it survives the damp soil and the rain. Electro galvanized looks nicer in the warehouse and it is cheaper, but once it is in the ground it tends to rust from the bottom up within a year or two, and by then the concrete is poured and there is nothing you can do. We only recommend electro galvanized for indoor, dry installations. For coastal sites and anything within a few kilometres of salt water, 304 is the sensible minimum and 316 is better still.

One more installation point that gets overlooked: the hook direction. The bent tail should point away from the direction the load will pull, not toward it. On an L type bolt, if you bend the tail toward the load, the bolt will straighten out and pull free. Set the tail perpendicular to the load line and it will hold. It sounds obvious written down, but we have had customers call us asking why their bolts came loose, and this was the reason more often than the bolt itself.

Every batch gets checked with thread go no go gauges, and we measure the overall length, the thread length and the bend angle on samples from each lot. Hardness is tested on every run so we know the grade is what the certificate says. For galvanized bolts we do a salt spray check to see how the coating holds up. Mill test certificates come with the order as standard. If your project needs SGS or a third party inspection, we can arrange it, but please tell us before production starts rather than after the goods are packed, because inspection slots get booked up and it is harder to fit in at the last minute.

Bolts are long and heavy and the threads bruise easily, so packing matters more than it does for nuts. We bundle them with the threads protected, then put them in woven bags or on wooden pallets depending on the size and the quantity. Nuts and washers go in separate bags so nothing scratches the thread in transit. If you want your own shipping marks on the bags, send us the artwork and we will print it.

FOB Tianjin is our usual term, and we ship to the Middle East, Africa and Southeast Asia regularly, so the forwarders and the documents are familiar ground. If you need CIF or DDP, give us the destination port and we will get a couple of rates and pass them on. For very long bolts we will also check whether they fit in a standard container before quoting, because an M64 at two metres does not always load the way people expect.

If you have a drawing, send it over. If you only have the equipment weight and the base size, send that and we will work out a proposal for you to check. Either way is fine, and there is no charge for the first round of drawings and sizing advice.

Hot Tags: anchor bolts, China anchor bolts manufacturers, suppliers, factory