pro.point 8619470 - Tungsten Preparation

34
Electrode Included Angle/Taper - DC Welding
Tungsten electrodes for DC welding should be ground longitudinally and concentrically with diamond wheels to a
specic included angle in conjunction with the tip/at preparation. Different angles produce different arc shapes and
offer different weld penetration capabilities. In general, blunter electrodes that have a larger included angle provide
the following benets:
• Last Longer
• Have better weld penetration
• Have a narrower arc shape
• Can handle more amperage without eroding.
Sharper electrodes with smaller included angle provide:
• Offer less arc weld
• Have a wider arc
• Have a more consistent arc
The included angle determines weld bead shape and size. Generally, as the included angle increases, penetration
increases and bead width decreases.
Tungsten Preparation
Always use DIAMOND wheels when grinding and cutting. While tungsten is a very hard material, the surface of a
diamond wheel is harder, and this makes for smooth grinding. Grinding without diamond wheels, such as aluminium
oxide wheels, can lead to jagged edges, imperfections, or poor surface nishes not visible to the eye that will contrib-
ute to weld inconsistency and weld defects.
Always ensure to grind the tungsten in a longitudinal direction on the grinding wheel. Tungsten electrodes are manu-
factured with the molecular structure of the grain running lengthwise and thus grinding crosswise is “grinding against
the grain.” If electrodes are ground crosswise, the electrons have to jump across the grinding marks and the arc can
start before the tip and wander. Grinding longitudinally with the grain, the electrons ow steadily and easily to the end
of the tungsten tip. The arc starts straight and remains narrow, concentrated, and stable.
grind longitudinal on the
grinding wheel
don’t grind across
the grinding wheel
at tip
2.5 times tungsten diameter
pointed tip
Electrode Tip/Flat
The shape of the tungsten electrode tip is an important process variable in precision arc welding. A good selection
of tip/at size will balance the need for several advantages. The bigger the at, the more likely arc wander will occur
and the more difcult it will be to arc start. However, increasing the at to the maximum level that still allows arc start
and eliminates arc wonder will improve the weld penetration and increase the electrode life. Some welders still grind
electrodes to a sharp point, which makes arc starting easier. However, they risk decreased welding performance from
melting at the tip and the possibility of the point falling off into the weld pool.
at spot diameter
included angle
Tungsten Diameter at Constant Included Current Range Current Range
Diameter the Tip - mm Angle - Degrees Amps Pulsed Amps
3/64” (0.040”) .250 20 05 - 30 05 - 60
1/16” (.062” & .060”) .500 25 08 - 50 05 - 100
1/16” (.062” & .060”) .800 30 10 - 70 10 - 140
3/32” (.93”) .800 35 12 - 90 12 - 180
3/32” (.93”) 1.100 45 15 - 150 15 - 250
1/8” (.125”) 1.100 60 20 - 200 20 - 300
1/8” (.125”) 1.500 90 25 - 250 25 - 350
These parts are manufactured in China and are oered as
replacement parts suitable for “TWECO” style torches.
Rating: 200A CO2 150A mixed gas, EN60974-7 @ 60% duty cycle. 0.6 to 1.2mm / 0.025” to 0.045
47/34” wires
TWC2 STYLE MIG TORCH
Description
1 Adjustable Nozzle Insulator
2 TW No.2 Metal Jacket Neck Assembly
45 Degreet Neck Assembly
60 Degreet Neck Assembly
3 Block C/W Spacer & Screws
4 Control Wire Terminals
5 Hose Clamp 18.5mm / (47/64)
6 Spring Cable Support Small & Ball Joint
7 Hyperex C/Assy X 10ft Euro
Hyperex C/Assy X 12ft Euro
Hyperex C/Assy X 15ft Euro
Hyperex C/Assy X 10ft
Hyperex C/Assy X 12ft
Hyperex C/Assy X 15ft
8 Handle With Hook & Screw
Description
9 Grey Trigger Switch
10 Hanger Hook
11 Screw Kit
112 Cable Terminal Male
13 Cable End Lock Nut (M12 X 1.0)
14 Cable Support
15 Gun Plug Housing C/W Nut
16 Gun Plug Screw
17 Gun Plug Nut
18 Gun Plug Terminal Female
19 TWC Euro Gun Plug Body
20 Gun Plug ‘O’ Ring
21 Liner Retaining Nut
*
Wear parts next page
*
Wear parts next page
1
2
356
14
12
13
18
15 16 17
19
20
21
8
7
9
10
11
4
Torch Model
Description Part Number
15ft
Welding Torch c/w Euro Fitting TWC2-15FTE
TWC2 Air Cooled Mig Welding Torch
Rating: 200A CO2 150A mixed gas, EN60974-7 @ 60% duty cycle. 0.6 to 1.2mm / 0.023” to 0.047” wires
TWC2 STYLE MIG TORCH
Spare Parts
Part Number Description
1 PWGA32 Adjustable Nozzle Insulator
2 U62J60 TW No.2 Metal Jacket Neck Assembly
WGA62A-45 45 Degreet Neck Assembly
WGA62A-60 60 DegreetNeck Assembly
3 U102 Block C/W Spacer & Screws
4 U244T Control Wire Terminals
5 UB5044 Hose Clamp 18.5mm / 0.728”
6 U141-6S Spring Cable Support Small & Ball Joint
7 U200-10E Hyperex C/Assy X 10ft Euro
U200-12E Hyperex C/Assy X 12ft Euro
U200-15E Hyperex C/Assy X 15ft Euro
Part Number Description
9 U92 Grey Trigger Switch
10 U152 Hanger Hook
11 U122FMS Screw Kit
112 UB1522 Cable Terminal Male
13 UXL1542 Cable End Lock Nut (M12 X 1.0)
14 UPA2041 Cable Support
15 UB1518 Gun Plug Housing C/W Nut
16 UB1526 Gun Plug Screw
17 UB1519/S Gun Plug Nut
18 UB1523 Gun Plug Terminal Female
19 U174EX-1 TWC Euro Gun Plug Body