Tig Welding Guide
Welding Stainless Steel
In TIG welding of stainless steel, welding rods having the AWS-ASTM prefixes of E or ER can be used as filler rods. However, only bare uncoated rods should be used. Light gauge metals less than 1/16" (1.6mm) thick should always be welded with DCSP using argon gas. Follow the normal precautions for welding stainless such as: Clean surfaces; dry electrodes; use only stainless steel tools and brushes, keep stainless from coming in contact with other metals.
Metal Gauge | Joint Type | Tungsten Size | Filler Rod Size | Cup Size | Shield Gas Flow | Welding Amps | Travel Speed | ||
Type | CFH (L/MN) |
PSI | |||||||
1/16" - 1.6mm | BUTT | 1.6mm | 1.6mm | 4, 5, 6 | Argon | 11 (5.5) | 20 | 80 - 100 | 12" |
FILLET | 90 - 100 | 10" | |||||||
1/8" - 3.2mm | BUTT | 1.6mm | 2.4mm | 4, 5, 6 | Argon | 11 (5.5) | 20 | 120 - 140 | 12" |
FILLET | 130 - 150 | 10" | |||||||
3/16" - 4.8mm |
BUTT | 2.4mm | 3.2mm | 5, 6, 7 | Argon | 13 (6) | 20 | 19200 - 250 | 12" |
FILLET | 2.4mm, 3.2mm | 225 - 275 | 10" | ||||||
1/4" - 6.4mm | BUTT | 3.2mm | 4.8mm | 8, 10 | Argon | 13 (6) | 20 | 275 - 350 | 10" |
FILLET | 300 - 375 | 8" |
Welding Low Alloy Steel
Mild and low carbon steels with less than 0.30% carbon and less than 1" (2.5cm) thick, generally do not require preheat. An exception to this allowance is welding on highly restrained joints. These joints should be preheated 50 to 100°F (10 to 38°C) to minimize shrinkage cracks in the base metal. Low alloy steels such as the chromium-molybdenum steels will have hard heat affected zones after welding, if the preheat temperature is too low. This is caused by rapid cooling of the base material and the formation of martensitic grain structures. A 200 to 400°F (93 to 204°C) preheat temperature will slow the cooling rate and prevent the martensitic structure.
Metal Gauge | Joint Type | Tungsten Size | Filler Rod Size | Cup Size | Shield Gas Flow | Welding Amps | Travel Speed | ||
Type | CFH (L/MN) |
PSI | |||||||
1/16" - 1.6mm | BUTT | 1.6mm | 1.6mm | 4, 5, 6 | Argon | 15 (7) | 20 | 95 - 135 | 15" |
FILLET | 95 - 135 | 15" | |||||||
1/8" - 3.2mm | BUTT | 1.6mm / 2.4mm | 2.4mm | 4, 5, 6 | Argon | 15 (7) | 20 | 145 - 205 | 11" |
FILLET | 145 - 205 | 11" | |||||||
3/16" - 4.8mm |
BUTT | 2.4mm | 3.2mm | 7, 8 | Argon | 16 (6.5) | 20 | 210 - 260 | 10" |
FILLET | 210 - 260 | 10" | |||||||
1/4" - 6.4mm | BUTT |
3.2mm |
4.0mm | 8, 10 | Argon | 18 (8.5) | 20 | 240 - 300 | 10" |
FILLET | 240 - 300 | 10" |
Welding Aluminium
The use of TIG welding for aluminium has many advantages for both manual and automatic processes. Filler metal can be either wire or rod and should be compatible with the base alloy. Filler metal must be dry, free of oxides, grease, or other foreign matter. If filler metal becomes damp, heat for 2 hours at 250°F (121°C) before using. Although ACHF is recommended, DCRP has been successful up to 3/32" (2.4mm), DCSP with Helium shield gas is successful in mechanized applications.
Metal Gauge | Joint Type | Tungsten Size | Filler Rod Size | Cup Size | Shield Gas Flow | Welding Amps | Travel Speed | ||
Type | CFH (L/MN) |
PSI | |||||||
1/16" - 1.6mm | BUTT | 1.6mm | 1.6mm | 4, 5, 6 | Argon | 15 (7) | 20 | 60 - 80 | 12" |
FILLET | 70 - 90 | 10" | |||||||
1/8" - 3.2mm | BUTT | 2.4mm | 2.4mm / 3.2mm | 6, 7 | Argon | 17 (8) | 20 | 125 - 145 | 12" |
FILLET | 2.4mm/1.6mm | 140 - 160 | 10" | ||||||
3/16" - 4.8mm |
BUTT | 3.2mm | 3.2mm | 7, 8 | Argon | 21 (10) | 20 | 195 - 220 | 11" |
FILLET | 210 - 240 | 9" | |||||||
1/4" - 6.4mm | BUTT | 4.8mm | 3.2mm | 8, 10 | Argon | 25 (12) | 20 | 260 - 300 | 10" |
FILLET | 280 - 320 | 8" |
Welding Titanium
Small amounts of impurities, particularly oxygen and nitrogen, cause embrittlement of molten or hot titanium when above 500°F (260°C). The molten weld metal in the heat-affected zones must be shielded by a protective blanket of inert gas. Titanium requires a strong, positive pressure of argon or helium as a backup on the root side of the weld, as well as long, trailing, protective tail of argon gas to protect the metal while cooling. Purge chambers and trailing shields are available from CK Worldwide to assist in providing quality results.
Metal Gauge | Joint Type | Tungsten Size | Filler Rod Size | Cup Size | Shield Gas Flow | Welding Amps | Travel Speed | ||
Type | CFH (L/MN) |
PSI | |||||||
1/16" - 1.6mm | BUTT | 1.6mm | None | 4, 5, 6 | Argon | 15 (7) | 20 | 90 - 110 | 10" |
FILLET | 110 - 150 | 8" | |||||||
1/8" - 3.2mm | BUTT | 2.4mm | 1.6mm | 5, 6, 7 | Argon | 17 (8) | 20 | 190 - 220 | 9" |
FILLET | 210 - 250 | 7" | |||||||
3/16" - 4.8mm |
BUTT | 2.4mm | 3.2mm | 6, 7, 8 | Argon | 21 (10) | 20 | 220 - 250 | 8" |
FILLET | 240 - 280 | 7" | |||||||
1/4" - 6.4mm | BUTT | 3.2mm | 3.2mm | 8, 10 | Argon | 25 (12) | 20 | 275 - 310 | 8" |
FILLET | 290 - 340 | 7" |