Description of down the hole hammer drilling
With down the hole hammer drilling, the drill principle consists of a combination of percussion and rotation. Unlike the top hammer, here the hammer drill is located directly in the borehole. These devices, known as ‘down-the-hole hammers’, are connected to the rotating drill pipes.
The down the hole hammer drilling is driven directly by the flushing medium. Compressed air is usually used for this purpose. Special procedures, though, can also involve flushing with water. The flushing medium is pressed through the drill pipes, down-the-hole hammer and drill bit and is forced back out at the mouth of the borehole, along with the loosened drill cuttings, through the annular gap between the drill pipes and the borehole wall.
Down-the-hole hammers are mainly used for drilling boreholes into hard rock in bedrock. These boreholes serve as anchor holes, blast holes, injection holes and pilot holes.
In the field of anchoring technology, this process can be used to produce both short- and long-term anchors. Typical applications include:
Anchored retaining walls
Building pit supports
1. Q: Are you trading company or manufacturer?
A: We are original equipment manufacturer.
2. Q: How long is your delivery time?
A: It is according to the model and quantity.
Generally it is 3-5 days if the machines are in stock.
It will be 15-30 days if you want to customize the machines.
3. Q: Do you provide samples? Is it free or extra?
A: Yes, we could offer you the sample machine.
But it's not free. You need to pay for the sample and the cost of freight.
4. Q: What is your terms of payment?
A: We accept T/T, Western Union, Money Gram, Paypal, Alibaba Escrow etc.
Payment<=USD 5000, 100% in advance.
Payment>=USD 5000, 30% T/T in advance, balance before shipment