I'm looking at obtaining the above taps and dies in the 3/4" NC & NF, 7/8" NC & NF, and 1" NC & NF sizes. With the old farm machinery I'm having to repair, bolts and nuts in these particular sizes, especially the NC pitch, are often encountered. I will be doing the threading by hand, no lathe or mill work. I want something not as brittle as carbide, but would like for it to retain its sharpness. Some work will be re-threading of dinged and/or rusty parts, while occasionally new threads will need to be cut. The parts steel will most often be mild steel, although there will be occasion for working with cast iron (sprockets) and alloy steel (shafts). The choices of material for the "reasonably priced" taps and dies from manufacturers on par with the Hanson and Irwin lines -- no, I'm not even considering Harbor Freight -- are high-carbon steel and high-speed steel. Since I won't be needing all of the HSS qualities as I will not be machine threading, I assume that HSS being a "tool steel", the extra cost of HSS over HCS is probably worth it, especially if I will be using dies deemed as "rethreading only" for cutting "new threads". Is there anything I'm missing in my thinking ? Also, what really is the difference between a "rethreading" die and that what I call a "new thread cutting" die ? Is it that the "new" threading dies are generally adjustable -- hence they tend to be round in shape -- while the "rethreads" are not adjustable and tend to be hex shaped ? Do the "new" dies have more of a lead-in chamfer on their "starting" side that the "rethreads" ? And are "new" dies generally made from a harder, higher grade of tool steel than HSS and are also made stronger than "rethreads" to endure the added stress and cutting resistance of new threads, as well as thicker to accomodate more "full-cutting threads" ? I won't even go into the subject of taps -- too many choices there !! All responses will be welcomed ! Thank you for reading this far ! - Dennis Anderson "Serious Machining" Group Owner

I would not spend ANY money on Carbon Steel. The stuff is like glass. It breaks at the slightest excuse and you spend your life trying to get the pieces out. HSS is the way to go and its not just for machine threading. All my hand tapes and dies are HSS (Unless I spend the extra money and get Cobalt).

Jim B. Owner http://finance.groups.yahoo.com/group/southbendheavy10/ http://finance.groups.yahoo.com/group/southbendheavy10files/ co-owner. NJ_LoganLatheOwners@... moderator http://groups.yahoo.com/group/southbendlathe/ Projects_For_Home_Shop_Metal_Fabricators

I'm looking at obtaining the above taps and dies in the 3/4" NC & NF, 7/8" NC & NF, and 1" NC & NF sizes. With the old farm machinery I'm having to repair, bolts and nuts in these particular sizes, especially the NC pitch, are often encountered. I will be doing the threading by hand, no lathe or mill work. I want something not as brittle as carbide, but would like for it to retain its sharpness. Some work will be re-threading of dinged and/or rusty parts, while occasionally new threads will need to be cut. The parts steel will most often be mild steel, although there will be occasion for working with cast iron (sprockets) and alloy steel (shafts). The choices of material for the "reasonably priced" taps and dies from manufacturers on par with the Hanson and Irwin lines -- no, I'm not even considering Harbor Freight -- are high-carbon steel and high-speed steel. Since I won't be needing all of the HSS qualities as I will not be machine threading, I assume that HSS being a "tool steel", the extra cost of HSS over HCS is probably worth it, especially if I will be using dies deemed as "rethreading only" for cutting "new threads". Is there anything I'm missing in my thinking ? Also, what really is the difference between a "rethreading" die and that what I call a "new thread cutting" die ? Is it that the "new" threading dies are generally adjustable -- hence they tend to be round in shape -- while the "rethreads" are not adjustable and tend to be hex shaped ? Do the "new" dies have more of a lead-in chamfer on their "starting" side that the "rethreads" ? And are "new" dies generally made from a harder, higher grade of tool steel than HSS and are also made stronger than "rethreads" to endure the added stress and cutting resistance of new threads, as well as thicker to accomodate more "full-cutting threads" ? I won't even go into the subject of taps -- too many choices there !! All responses will be welcomed ! Thank you for reading this far ! - Dennis Anderson "Serious Machining" Group Owner

I believe the lead and geometry of a rethreading die is also much different than a cutting die. Its not just the split, adjusting feature that is different.