Details needed for welding O1 tool steel

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I need to know the specs for welding 01 tool steel - details of the project are below.I'm going to be trying my hand at making some woodworking handtools - mortise chisels, specifically. (Mortise chisels, for anyone unaware & curious are the type of chisel used to chop mortises - the part in mortise & tenon joinery that is the recess, accepting the entry of the tenon portion.) Now, because of all the pounding on the chisel's handle with a mallet, the handle's position on the chisel tang is strengthened, or bolstered, by a flange that the handle sits on called a 'bolster'. The bolster is basically a 'shelf' around the edge of the chisel blade.Mortise chisel blades - true mortise chisels, not sash mortise chisels - are typically 1/2 thick and of basic standard widths like 1/4", 3/8", 1/2", etc. Blade length is usually 5-6" or so, with the tang being another ~4" (overall blade length around 10")Blade formation will be pretty straight forward: O1 tool steel can be purchased in various widths and thicknesses which, thankfully, correlate pretty well with typical blade dimensions. My plan for fastening bolsters to the blades are basically to take a rectangular piece of 01 steel, mill a hole in the centre sized to the blade dimensions, slide it in place and weld it.Following fastening of the bolster and shaping of the blade and bevel, I'll be heat-treating the blade to a Rockwell hardness about Rc60 or so.The welder I'm hoping to use is my Lincoln Electric SP-125 Plus. What kind of wire and settings would I be looking at with this type of application? Any other considerations I should keep in mind?Before you criticize someone, walk a mile in their shoes. That way, when you criticize them, you're a mile away. And you have their shoes.Roland
Reply:Most tool steels use about the same welding procedure. Oil hard require a preheat of 300-400*F. Your SP 125 is fine. Use an Oil hard filler. Use the smallest possible electrode diameter at the lowest possible amperage to minimize the heat affect of welding penetration. Never weld a tool steel at room temp. Preheat and post heat must be maintained throughout the total welding cycle. Anneal the base metal whenever possible. Parts must be clean. Lightly peen each bead while weld is red hot. Stringer passes only. No weave. Check temp often and stay within the specified range throughout welding procedure. After welding cool tool in still air to 210*F and temper immediately. Don't cool to room temp before tempering. --Gol'
Reply:Originally Posted by Go1lumMost tool steels use about the same welding procedure. Oil hard require a preheat of 300-400*F. Your SP 125 is fine. Use an Oil hard filler. Use the smallest possible electrode diameter at the lowest possible amperage to minimize the heat affect of welding penetration. Never weld a tool steel at room temp. Preheat and post heat must be maintained throughout the total welding cycle. Anneal the base metal whenever possible. Parts must be clean. Lightly peen each bead while weld is red hot. Stringer passes only. No weave. Check temp often and stay within the specified range throughout welding procedure. After welding cool tool in still air to 210*F and temper immediately. Don't cool to room temp before tempering.
Reply:No those are just a few basic rules I was taught in college about tool and die welding. --Gol'
Reply:Thanks Go1lum. As Dave noted, the O1 is in the annealed state. So, would that change the recommendations around preheating, filler wire choice, shielding gas and general concern about temperature ranges?Up to now, I've been using 0.024" ER70S-6 wire and C-25 shielding gas. I also have 0.035" ER70S-6 available but haven't gotten around to using it. Would these be useable for this, or would I be looking at something different?Out of curiosity, what does the light peening do? Something about internal stresses?You mentioned checking the temperature often - how do you get an accurate measurement of the temperature?When you mention 'tempering' above, are you referring to the heat treating process in general, or are you referring to the low-temperature soak at ~450F that happens at the end of the heat treating process to remove thermal stresses?What I was planning on doing was to stack a fairly stout weld bead on the blade side of the bolster, which I'd then fair down with grinding into a smooth, curving transition from the bottom of the bolster to the blade sides. Once all the blades are finished, I was planning on doing the heat treating process.Because the heat treating follows after, does the same dimension of concern about the heat-affected zone need to be maintained?Before you criticize someone, walk a mile in their shoes. That way, when you criticize them, you're a mile away. And you have their shoes.Roland
Reply:Go1lum's advice is more appropriate for welding on O-1 tool steel that's already been heat treated.  Since you're planning on heat treating the chisels after you welding them, there's little prep required.  I'd ask your welding supply shop to provide you some filler wire that's as close as possible to the chemistry for the steel you buy.  Your steel supplier should be able to give you the chemistry info.Weld as you would for mild steel, then follow up with the recommended heat treatment.  The heat, quench, and temper for O-1 should eliminate any of the changes in grain structure created by the welding process.  The only precautions I can think of off the top of my head, would be to avoid any rapid cooling of the weldment.  This could lead to cracking.  The pieces you're welding sound like they're small enough that pre-heating to ~350°F is not strictly necessary.  If you have the capability to pre-heat the material, it wouldn't hurt.Just a friendly reminder, plan ahead for the distortion likely to result from welding.  Since you're making precision tools, you'll want to do everything you can to prevent distortion from the welding.  Your O-1 heat treatment will take care of any residual stresses in the weld HAZ.  But straightening warped tool steel is a fate better avoided.you can monitor minimum temperatures using Tempil sticks.  They're essentially crayons with very precise melting temperatures.  You buy a tempil stick with the temp min you need to reach.  Mark the steel in a non-critical location.  Heat the material, and watch for your marks to melt.Last edited by A_DAB_will_do; 02-19-2008 at 08:08 PM.Reason: add tempil stick info
Reply:Thanks - that's great info! I'll look into Tempil sticks - never heard of those before, but they sound like exactly the sort of thing that's needed!In terms of preventing the distortion from welding, my hazily-formed was to essentially 'stitch' the welds - doing a portion of the weld on one of the four sides of a chisel, then move onto another chisel. Once they're all done, give them some time to cool then go back and do a stitch on the opposite side from the last one...and so on. It'll take awhile, but it's kind of a back-burner project and something I'm just doing for myself and maybe a friend or two - not a production project.Is there anything else you'd recommend to prevent distortion from welding?Before you criticize someone, walk a mile in their shoes. That way, when you criticize them, you're a mile away. And you have their shoes.Roland
Reply:What are you going to use for the actual handle material?
Reply:Is the 01 oil hardened,water hardened or air hardened?
Reply:01 is oil hard if its not been HT then just weld it no pre heat needednormalize work then HT and temper i have made a bunch of tools this way none have ever brokenChuckASME Pressure Vessel welder
Reply:Originally Posted by MrRodeoCCWhat are you going to use for the actual handle material?
Reply:Originally Posted by Donald BranscomIs the 01 oil hardened,water hardened or air hardened?
Reply:Originally Posted by chopper501 is oil hard if its not been HT then just weld it no pre heat needednormalize work then HT and temper i have made a bunch of tools this way none have ever broken
Reply:normalize - to heat up the steel and hold it at a certain temperature for a certain length of time, and then to slowly cool it.  It allows the steel to 'relax' and get it's grain back into size/shape after the steel has been welded or machined or formed.Normalizing temperatures are typically hotter than stress-relieving, annealing, or hardening temperatures.
Reply:well for 01 heat ti up till a magnet will no longer stick set it some place to cool slowlyChuckASME Pressure Vessel welder
Reply:Getting back to part of the question I had in the OP, is there a specific wire that's used on annealed O1 steel?Before you criticize someone, walk a mile in their shoes. That way, when you criticize them, you're a mile away. And you have their shoes.Roland
Reply:well the tools i made i used er70-6 thats what i had on handfor what you want to do im not shure what to useChuckASME Pressure Vessel welder
Reply:I dug out some references I have:Your O1 tool steel can be welded with any filler metal suitable for mild steel. The trick is, if you use a generic filler for mild steel, the weld metal will dilute the tool steel in the vicinity of the weld.  In effect, the weld and surrounding material won't be tool steel any longer.  That's why I recommended finding a filler that has the same chemistry as your O1 steel.  Then the weld will have the same properties(strength, ductility, hardness, etc) as the base metal, and will respond to the heat treatment in the same fashion as the base metal.Your O1 tool steel has a nominal chemistry of :0.9 wt% Carbon1 wt% Manganese0.5 wt% Chromium0.5 wt% Tungsten97% IronThere are specialists who manufacture filler metals for welding tool steels.  Here is a contact that was recommended to me in the past.Stephen Charles Weld Mold Company 750 Rickett RoadBrighton, MI  481161-800-521-9755www.weldmold.comWeldmold filler 935 will work for you, and they have it in MIG wire form:http://www.weldmold.com/pdf/935.pdfHere's a short webpage with some useful advice on welding tool steel.http://www.moldmakingtechnology.com/...es/040104.htmlHere's an example of a filler metal that might suit your needs.  I'd talk with the company before ordering.  the page says they supply this as stick electrodes and as TIG filler wire.  I know you're looking for a MIG wire, but this might get you closer to what you want:http://webapp1.cronatronwelding.com/...temNum=CW04850 Originally Posted by Roland CoppensGetting back to part of the question I had in the OP, is there a specific wire that's used on annealed O1 steel?
Reply:Thanks man - exactly the kind of info I needed!Before you criticize someone, walk a mile in their shoes. That way, when you criticize them, you're a mile away. And you have their shoes.Roland