GTAW (TIG) Procedure for Tool Steels
Procedure
- Identify the tool steel to be welded. While there are many variations of the tool and die steels, the most common are: 
- Prepare the surface to be welded. Remove all foreign matter and rough edges. Make sure that only the original base metal is exposed. 
- Select the proper electrode per the chart. Preheat the tool steel to be welded per the chart. 
- Use AC or DC, reverse polarity, with the lowest possible amperage setting for good fusion. 
- Using a striker plate, carry the arc to the area to be welded. 
- Maintain preheat temperature while welding. 
- Two or more passes should be used to minimize dilution of the base metal. Peen each pass rapidly to stress relieve. 
- Postheat or temper the deposit per the chart. 
- If heat treating is desired, use the annealing, hardening and quenching recommendations in the chart. 
- For checking proper welding temperature, use a temperature indicator. 
- With reference to "Step 7" above, 3-SMW is recommended as a "cushioning" or "padding" pass adjacent to the base metal. This minimizes dilution of the base metal and offers a softer, more ductile alloy next to the higher hardness base metal. 3-SMW does not respond to heat treatment, so it should not be exposed to the finished weld area. 3-SMW also has less hardness than the tool steel overlay. 
| Water hardening | W-1 through W-5 | 
| Oil Hardening | O-1 through O-6 | 
| Air Hardening | A-2 through A-10 | 
| High Speed | M-1 through M-44 | 
| Hot Work | H-10 through H-43 | 
Shielding Gas: Argon is recommended as the shielding gas.
Sizes Available: Each of these Aufhauser (GTAW-TIG) tool steel alloys (also Aufhauser 3-SMW) are offered in the following sizes:
Packaging: All sizes are packed in five pound tubes, four tubes per twenty pound carton.
Use the following chart as a guide in the effective and economical salvage of costly tools and dies:
| Tool Steel to be Welded | TIG Alloy Name | Sizes (Inches) | Stock No. | RC Hardness as Deposited | Preheat °F | Anneal °F | Harden °F | Post-Heat °F | Quench | 
|---|---|---|---|---|---|---|---|---|---|
| Air Hardening | 3-AH | 1/16 3/32 1/8 | 003AH30 003AH50 003AH60 | 48 - 52 | 300 - 1000 | 1500 - 1600 | 1750 - 1850 | 300 - 1000 | Air | 
| Oil Hardening | 3-OH | 1/16 3/32 1/8 | 003OH30 003OH50 003OH60 | 48 - 56 | 250 - 400 | 1425 - 1450 | 1425 - 1500 | 250 - 400 | Oil | 
| Water Hardening | 3-WH | 1/16 3/32 1/8 | 003WH30 003WH50 003WH60 | 52 - 58 | 275 - 450 | 1425 - 1450 | 1425 - 1450 | 275 - 450 | Water | 
| High Speed Steel | 3-HSS | 1/16 3/32 1/8 | 003WH30 | 58 - 63 | 1000 | 1600 | 2200 - 2225 | 1000 | Oil | 
| Hot Working | 3-HW | 1/16 3/32 1/8 | 003HW30 003HW50 003HW60 | 52 - 55 | 900 - 1200 | 1500 - 1600 | 1750 - 1850 | 900 - 1200 | Air | 
| Flame Hardening | 3-FH | 1/16 3/32 1/8 | 003FH30 003FH50 003FH60 | 45 | 800 - 900 | Use S.A.E. 4130 Procedure | |||
