AAK Hydraulic Relief Valves Surface Roughness Ra of 0.1~0.2μm

Marten is an old customer from a Dutch hydraulic company. He is very cautious
in the business of hydraulic valves and never changes hydraulic valve suppliers
easily. AAK hydraulic valve reached the first cooperation of hydraulic relief
valves under the introduction of his friend.  It has been 3 years, and he
orders 2 types of hydraulic relief valves with AAK every year. We have a very
good personal relationship, and often communicate about some hydraulic valve
technology.  

Last month, Marten had an order for a special hydraulic relief valve that
requires a surface roughness Ra of 0.1~0.2μm, which is more than 4 times
accurate than the normal standard.  All the hydraulic relief valves of this
series are purchased from the hydraulic valve manufacturer that he has
cooperated with for 5 years. This manufacturer has tried this hydraulic relief
valve for 3 consecutive times, but the Ra value is still not up to
standard.  Marten thinks of AAK hydraulic valve. In the email, he has been
emphasized that the surface roughness Ra value of hydraulic relief valve must
reach 0.1~0.2μm.  According to the hydraulic relief valve drawings sent by
Marten, after discussion, AAK engineers expressed 90% certainty that the Ra
value could reach 0.1~0.2μm.  Marten seems to see hope, but also fear.  He
asked AAK TO try samples immediately. At the same time, the original hydraulic
relief valve manufacturer was also requested to continue the sampling.  

AAK arranged the most experienced technicians to operate the knife, first of
all in the rough turning stage, cutting depth adjustment to 0.8~1.5mm, feed to
0.2~0.3mm/r, cutting speed to 30~50m/min and so on, after the rough turning Ra
value is 12.5~6.3μm, while leaving 0.5~1mm as fine turning
margin;  Secondly, in the finishing stage, the cutting depth is adjusted to
0.1-0.3mm and the small feed is 0.05-0.2mm /r. At the same time, the cutting
speed is ensured to reach the moderate value and the roughness Ra value is
ensured to reach 0.2-0.16μm.  AAK sent the hydraulic relief valve samples 10
days later.  

On the 3rd day after receiving the samples of AAK hydraulic relief valve,
Marten informed us by email that the Ra value of the surface roughness was up
to standard. At the same time, he also informed that the original hydraulic
relief valve manufacturer also continued the sampling, but failed in 5 samples
for 5 times, while AAK succeeded in one time. He asked us to catch time to
prepare material, he would discuss the PO of hydraulic relief valve with AAK
after he confirmed the order quantity and the delivery date with his customer.

For high precision hydraulic relief valve roughness Ra value, in addition to
use high precision lathes, good technicians are the key, to be good at
adjusting lathe parameters according to different processing, for this
hydraulic relief valve, AAK technician advantages are reflected in:  

1. High speed and small cutting depth and feed are selected to reduce the
residual area and Ra value. When finishing, select high-speed and small cutting
depth and feed rate to reduce the residual area and reduce the Ra value.
2. Grinding the front and rear tool surfaces of the turning tool with engine
oil, can effectively reduce the Ra value of the workpiece surface.
3. The 32 year old mechanic operating the machine tool, who can know whether
the Ra value of the hydraulic relief valve is normal or not by just listening
to the processing sound.

The Ra value of AAK hydraulic relief valve is 4 times that of the conventional
standard and 2 times that of its peers. You can also have a small try.

https://www.aakindustry.com/info-detail/hy , draulic-relief-valves-aak232

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