? 5/8-11 Thread Milling

[Bill Sutton@Accurate Machine]

We are looking at a part that requires a 5/8-11 thread thru 4 7/8 thick A-36 Material. I have done some thread milling but not that thick. I was wondering if anyone has done something( with luck) like this that thick with thread milling.

And what manufacture has that length.

I dont think with a a tap and horse power we will not be able to do this.

Any suggestions.

 

Thanks

[chris m]

Absolutely no help, but why in the wide wide world would anybody need that much f-ing thread?

[Guest]

I cannot imagine you'll find a tool to thread mill that deep.

 

If someone has done it, it was with luck and alot of it

 

[Mgrenier]

No thread milling possible here. You will have to tap them. OSG has a line of long taps that works very well. We use them often without any problems.

[G Caputo]

Didn't try to look up anything in a catalog, but how about a lathe boring bar with a threading insert?

[robk]

I am also wondering why????

[John13]

Long bolts?

[Bill Sutton@Accurate Machine]

Just got of the phone with the customer and they will allow a 1.5 c'bore leaving roughly 3 3.8 worth for thread.

 

Helps out a litle but still a lot of thread

[Kannon]

well I guess they shouldnt have to worry bout it strippin out.

[Guest CNC Apps Guy 1]

I'd either single point it with a lathe threading tool or peck tap with the long tap.

 

JM2C

[Psychomill]

3-3/8 long (4-7/8 overall including c'bore), 5/8 thread in A36??!!!???

 

I wouldn't even bother trying to threadmill it even if you had a solid carbide one built. It would be hell in trying to keep from deflection. I'm with Martin here ( and James )... get a pulley tap built for it and peck tap it...

 

[Storkman]

most threadmills I have looked up only go 2.5x the diameter max. Sounds like a tap to me as well.

[Andy]

We tap an 11/16 x 11 GL3 2.5 deep in steel. Had taps made sp pt from Regal. No way thread mill.

[Slick]

Don't have time for the search, but there was a post a couple years back about Engineering Knowledge, a machinist's test, or something. One of the questions was how deep a threaded hole needs to be for maximum strength. Sounds like you should give yer customer a lesson.

 

If all else fails, I'm with James, single point or peck.

 

Be sur eto let us know what you ended up doing!