Lance
Plastic
- Joined
- Jan 13, 2006
- Location
- Pensacola, FL
Hello,
I've got some old thread roller dies that I need to regrind. I'm not rolling threads, but simply rolling a .050R groove and forming a chamfer on the end of some 1008 mild steel pins that have been cold headed.
I have no idea what the material is, but it is definitely hardened. I presume it's A2 or D2 or something similar, but some die shops do make them out of M4.
Right now I'm simply trying to square up/flatten the die faces on my surface grinder, before grinding in the raised groove. I'm using a 46 grit H hardness white grinding wheel (AA46-H8V40) is what the wheel says. I also have a finer Norton 38A80 that I tried. Neither wheel wants to cut worth a darn. I'm getting black lines (burn marks) in the part even with very light cuts, .0002", and on a freshly dressed wheel. I'm also using flood coolant. It also appears that there is not that many sparks when grinding. Further reinforcing the feeling that the wheel is pushing off and not cutting.
It's as if the wheel is loading up immediately. I'm totally stumped. I've ground heat treated A2, D2 and S7, mild steels, stainless etc... before without any problems at all. The material these dies are made out of is killing me though.
Any recommendations on a grinding wheel that will ease my pains (grit, coarseness, hardness etc...) Thanks for any help.
I've got some old thread roller dies that I need to regrind. I'm not rolling threads, but simply rolling a .050R groove and forming a chamfer on the end of some 1008 mild steel pins that have been cold headed.
I have no idea what the material is, but it is definitely hardened. I presume it's A2 or D2 or something similar, but some die shops do make them out of M4.
Right now I'm simply trying to square up/flatten the die faces on my surface grinder, before grinding in the raised groove. I'm using a 46 grit H hardness white grinding wheel (AA46-H8V40) is what the wheel says. I also have a finer Norton 38A80 that I tried. Neither wheel wants to cut worth a darn. I'm getting black lines (burn marks) in the part even with very light cuts, .0002", and on a freshly dressed wheel. I'm also using flood coolant. It also appears that there is not that many sparks when grinding. Further reinforcing the feeling that the wheel is pushing off and not cutting.
It's as if the wheel is loading up immediately. I'm totally stumped. I've ground heat treated A2, D2 and S7, mild steels, stainless etc... before without any problems at all. The material these dies are made out of is killing me though.
Any recommendations on a grinding wheel that will ease my pains (grit, coarseness, hardness etc...) Thanks for any help.