AAK hydraulic valve block adopts multi edge particle cutting with diamond reamer, the accuracy can reach 0.002mm, and the surface roughness can reach Ra 0.2um, the precision is twice that of other hydraulic valve manufacturers, and there is no iron filings. Because the price of AAK hydraulic valve block is a little higher than that of peers, LIEBHERR excluded AAK from the supplier list. However, 3 months later, LIEBHERR still placed an order for the hydraulic valve block with AAK. This morning, I received an order for hydraulic valve block from Herta from LIEBHERR company in Germany, which was a little unexpected. Because this is the hydraulic valve block that AAK sent sample for 3 months ago. Since the sample was sent, there was no news about the sample. After several follow up emails, the reply was "unqualified". I asked about the reason why the hydraulic valve block was unqualified, but didn't get reply. Now I can't understand why the order comes to us 3 months later. Herta is mainly responsible for the procurement of hydraulic accessories of LIEBHERR. In the first half of this year, his company needed to purchase a batch of high-precision hydraulic valve blocks for hydraulic excavators. At that time, he selected 5 hydraulic valve factories to send samples to test the quality and conduct assembly tests. 3 months later, after comprehensive comparison, their technical team found that the test data of AAK hydraulic valve block was the best among the 5 hydraulic valve manufacturers. I asked Herta curiously why the reply he gave us 3 months ago was "unqualified". He replied that your quotation was unqualified and more expensive than the other 4 hydraulic valve manufacturers, so we judged AAK to be unqualified. After 3 months of testing, the technical team believes that AAK's hydraulic valve block has the highest precision, the strongest durability and the simplest follow-up maintenance. Although the price of AAK is a little higher than that of other suppliers, according to the comparison of various parameters, the hydraulic valve block of AAK can enable LIEBHERR to reduce the cost of subsequent maintenance, so the technical department designated AAK to supply this hydraulic valve block. Herta asked us why some parameters of AAK hydraulic valve block are twice better than those of peers? The high precision of AAK hydraulic valve block mainly comes from the diamond reamer used in AAK machining center, which is a multi edge particle cutting. In the reaming process, the chips are hidden between the diamond particles and thrown out via coolant flushing and high-speed rotation, so that the chip removal in the first step is complete.