Page 690 - Yamawa_European_Catalogue_YEU21
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15. Surface Treatment
Intro
The best surface treatment is applied to each tap depending on the tapping purpose.
Characteristics and eff ectiveness of surface treatment are introduced at next section.
SP
Oxidizing
• This treatment was processed by using HOMO furnace being made by LEED AND NORTHUP company USA in 1938, and it is called HOMO
treatment. This treatment is also called vapor treatment and steam treatment. Through this treatment, Fe 3 O 4 layer of blue black color is
SL produced over the tool surface.
• Oxidization treatment produces porous layer on tool’s surface. This porous layer works as oil pocket to reduce friction, to avoid welding
and to improve the surface roughness of internal screw. Moreover, longer tool life is expected because the treatment reduces the
remaining stress of HSS tools.
PO • This treatment does not increase the hardness on tool surface. Using the furnace of YAMAWA original design and choosing the proper
treatment time, we have marked good result of oxidizing for YAMAWA HSS tools.
• Stainless steel and low carbon steel are the materials that are easy to get welding. We are applying this treatment to the special purpose
taps for these materials to get good result. Further due to the reduction of friction force, this treatment has good result for wide range of
steel type material.
ST
• We combine oxidizing with nitriding for the taps designed for thermal refined steels of high carbon steels and alloy steels. This double
treatment wins good reputation of the market.
ROLL
Thickness of oxide layer and the time of treatment Comparison between bright and oxide treated
CARBIDE (μm)
CUTTING CONDITION
Tap: SP-VA/M8×1.25/ISO2(6H)
Material: AISI304 (165-171HB)
LONG Hole size: Ø 6.8 mm
Tapping Length: 12 mm (through hole)
Tapping Speed: 7.2 m/min
Cutting oil: Insoluble oil
Thickness of oxide layer Number of tapped holes
HAND Tapping Machine: CNC tapping machine
TAPS
EG (STI)
SPECIAL
THREADS,
GAUGES
THREAD
MILLS minute SP-VA design SP-VA
(Bright) (Oxide treated)
Treatment time
DIES
CENTER
DRILLS
Technical
info
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