For our mainly HSS drill bits products, there have different precess, such as roll forge, edge ground and milled.
Let us introduce these type as following:
1.Roll Forged: the high speed steel is stretched and twisted according to a certain extent in the heating and softening and then roll forged the flute.
For example: the 70mm overall length can be stretched to 100mm. So the roll forged process can save the materials and have a low cost. And the goods
Are very cheap.
2. Edge Ground: it is to fine finish the goods on the basis of roll forged and make the shank diameter more precious. So the goods are more easy to drill holes
And the outlook also looks better than before.
3.Milled: the high speed steel is milled the flute by the milling cutter. Because the material is not stretched or twisted, so the run-out of goods made by milled is more precise than the goods made by roll forged. At the same time, the milled process takes the semi-automatic machine, so it needs people to control the machine,
And this increase the cost. So in generally, the milled process in used for the large size of drill bits.
4.Fully ground is another process to manufacture the drill bits. As we know, in generally, the milled process in used for
the large size(>13mm)of drill bits. So for the normal size(≤13mm) drill bits, we take the fully ground process.
The fully ground process takes the automatic machine. And the high speed steel is grinding the flute by the emery cutter.
So it is very effective and has a very stable quality.
