dandrummerman21
Stainless
- Joined
- Feb 5, 2008
- Location
- MI, USA
On occasion I break out the thread mill when doing some one-off threads. I've got a couple iscar tool bodies with the full form thread inserts. Whenever I use them, it seems it takes significantly longer than tapping. And I think that is to be expected.
Although when I see people say "just threadmill it" on here, it seems to come with the undertone of, "it is plenty fast".
So my question is, how fast do you guys run your threadmills? A couple examples:
Lets say I have a 1/2-13 thread, 3/4" deep, in 1018 using one of these: 1/2-13 Variable Flute Carbide Thread Mill
Lakeshore's recommendations seem to be 350-500sfm, .0025-.0035ipt. middle of the road numbers would be about 4600rpm at 55ipm.
Harvey tool's recommendations are about 550sfm, .0016ipt. That is about 6000rpm at 38ipm. But harvey's guide also has an adjustment formula ((major - tool dia)/major), which ends up putting me at 11.4ipm
Are you guys really running these at 500sfm? I have a long running job, running the lakeshore threadmill, and we settled in at 2000rpm at 3/4ipm a long time ago. Tool life is pretty good, is consistant. I remember we tried going faster but settled in on this after a short period of trial and error, settling on the current numbers just because "it worked"
Another example (the real reason I'm asking):
I am running a one off repair job, where I need to mill a 4"-12 thread about 5 inches deep in some sort of steel (seems to cut easy, might be 1018 although the finish I got while boring the hole was nicer than I expected. The part is welded so I don't think it is 12L or similar)
The only tool I have for this is a boring bar from the lathe dept. 1.5" bar, approximately a 2" diameter. So it is basically a single point, single tooth threadmill. I am running 300sfm (573rpm) at about 8.5ipm (.015 per tooth!!!) now. I had started at like .003" but it really felt like it was creeping along way way way too slowly.
Even at this speed it takes about 40 minutes to complete the part (in this case, not a big deal, i wander off while it is cutting) but to you people who do this all the time, how fast can I ramp this up to? Can I expect to gain anything on this part?
Is there another place to look for even different threadmill information?
Although when I see people say "just threadmill it" on here, it seems to come with the undertone of, "it is plenty fast".
So my question is, how fast do you guys run your threadmills? A couple examples:
Lets say I have a 1/2-13 thread, 3/4" deep, in 1018 using one of these: 1/2-13 Variable Flute Carbide Thread Mill
Lakeshore's recommendations seem to be 350-500sfm, .0025-.0035ipt. middle of the road numbers would be about 4600rpm at 55ipm.
Harvey tool's recommendations are about 550sfm, .0016ipt. That is about 6000rpm at 38ipm. But harvey's guide also has an adjustment formula ((major - tool dia)/major), which ends up putting me at 11.4ipm
Are you guys really running these at 500sfm? I have a long running job, running the lakeshore threadmill, and we settled in at 2000rpm at 3/4ipm a long time ago. Tool life is pretty good, is consistant. I remember we tried going faster but settled in on this after a short period of trial and error, settling on the current numbers just because "it worked"
Another example (the real reason I'm asking):
I am running a one off repair job, where I need to mill a 4"-12 thread about 5 inches deep in some sort of steel (seems to cut easy, might be 1018 although the finish I got while boring the hole was nicer than I expected. The part is welded so I don't think it is 12L or similar)
The only tool I have for this is a boring bar from the lathe dept. 1.5" bar, approximately a 2" diameter. So it is basically a single point, single tooth threadmill. I am running 300sfm (573rpm) at about 8.5ipm (.015 per tooth!!!) now. I had started at like .003" but it really felt like it was creeping along way way way too slowly.
Even at this speed it takes about 40 minutes to complete the part (in this case, not a big deal, i wander off while it is cutting) but to you people who do this all the time, how fast can I ramp this up to? Can I expect to gain anything on this part?
Is there another place to look for even different threadmill information?