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Chaser material
The chasers will be manufactured in the grades HSS and HSSE. HSSE is
recommended when the strength of the material exceeds 900 N/mm².
All chasers are available as nitrided or coated version.
5.3. Polished section of the chaser
On the front side of the chaser the chipping- and the grinding angle
are grinded which constitutes the grinding area.
The cutter can be resharpened when getting blunt or showing nicks.
The chasers are resharpened in the same way as common tools. Only
a few points have to be noted which characterize tangential chasers.
A variety of angles which are relevant for thread cutting need to be
noted:
α = clearance angle
β = wedge angle
γ = chip angle
δ = grinding angle
Grinding scope
The resharpening of the chasers can be done on every all-purpose tool machine.
WAGNER
provides you with a clamping device which will enable you to mount the
®
chasers and to set the relevant angles.
Should you not be in possession of a tool grinding machine we recommend you use
a WAGNER
chaser skiving machine.
®
As cup wheels we do recommend conical cup wheels EKW 60 Jot with edge reinforce-
ment. They are available from WAGNER
When grinding chasers with low thread profiles it is very useful to adjust an illumina-
ted magnifier at the grinding device.
The choice of the chip angle
The degree of the chip angle is dependent on the material, the lubricant, the coolant
and the cutting speed as always when machining.
The chasers are delivered with a standard chip angle of 20°
The following table provides some reference values for resharpening of the chip ang-
le dependent on the material of the workpiece:
Material
Machining steel
Construction steel up to 500 N/m²
Construction steel from 500N/m²
High- alloyed steel (Stainless steel)
Pipes
Annealed cast iron fittings
Grey cast iron
MS 58
MS 60-62
Bronze
Copper
Aluminium alloy
.
®
Reference value of the chip angle in °
16 - 25
16 - 28
16 - 25
22 - 28
20 - 28
15 - 22
10 - 20
4 - 10
8 - 20
8 - 20
20 - 30
18 - 30
Figure 7: Angle at chaser
Table 1: Chip angles
Operating Manual ZR 26-I
Chasers
11
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