Thread tap suggestion

[Izzy]

I purchased 2 of these the other day. I've threaded over 200 holes in steel without much issue.

http://www1.mscdirect.com/CGI/NNSRIT...er=346%50mode=

if the link doesn't work - go to www.mscdirect.com - search for item #64510019 on page #325


for a drill bit I 'm having real good luck with these also
http://www1.mscdirect.com/CGI/NNSRIT...MPXNO=12580872

if the link doesn't work - go to www.mscdirect.com - search for item
#81134058 on page 49

[pugs]

Greenfields are good taps. I prefer OSG myself, have a OSG 1/4-20 cut type, helix flute that has over 3,000 holes in steel and still cuts a nice clean thread. The best taps are the ones that are designed and coated for the material you are working with. Taps are one of those areas where you get what you pay for.

[Lil Giants]

Originally Posted by pugs

The best taps are the ones that are designed and coated for the material you are working with. Taps are one of those areas where you get what you pay for.

The 3mm tapp I have is likely for steel (IDK), but I have tapped many of holes in aluminum with it. What's a special purpose 3mm tapp for aluminum look like?

[ihbuilder]

Originally Posted by Lil Giants

The 3mm tapp I have is likely for steel (IDK), but I have tapped many of holes in aluminum with it. What's a special purpose 3mm tapp for aluminum look like?

Joe from what I gather , it has to do with the coating . I get at lest 3000 holes with the tin coated and the black I just make sure I oil the tap and keep it clean for every hole . the only reason I brake them , is that darn shake I get . Gets worse when I'm tired ,so I learned to do something else or go to bed

[pugs]

Alot to do with the coating, some of the taps for stainless and other exotics have special grinds to the flutes that make them cut easier or break chips etc.

For aluminum I pretty much now only use form taps in my shop, Balax makes some good ones (threadfloer taps) as well as OSG. http://www.balax.com/ (Balax even makes a form tap that creates a locking thread in the part) Have used form taps in steel as well with great success, just don't have many form taps for steel yet. Biggest 2 advantages of the form taps are; no chips, and probably 5-6x tap life. I have a 1/4-20 form tap that has been used for 1" deep through holes in about 5,000+ holes and it still looks new.

Cut taps in aluminum, bright finish no coating works well, other wise ZirconiumNitride.

TIN coating works well in Steels as well as steam oxide with oil.

If buying new taps for steel I highly recommend getting spiral point taps for through holes (most of the small taps are this way, sometimes called gun taps). This spiral point pushes the chip out ahead of the tap and keeps from binding in the flutes. When using these types of taps you will notice how much easier they turn, and you don't need to keep backing the tap off to break the chips just turn till your through in one shot.

If doing blind bottom holes, the spiral flute taps work great at pulling the chips out just like a drill bit. Then you don't wind up packing the chips in the bottom of the hole etc.

[Lil Giants]

Spiral point tap is what I have, as I notice the chips being pushed forward. Using it for a blind hole is time consuming & the necessity for pressurized air to clean the hole often, as well as drilling a deeper hole than necessary. Need to get a "spiral flute" tap for blind holes.

Gosh it's GREAT having a journeying machinist on the forums, learning lots. Thanx for taking the time to edumacate us.

[Vanisle]

I haven't looked far and wide but the options at McMaster Carr are limited in the small taps, ex. 1-72. I think the real options for the different types of taps start at 2-56. I may have to expand my buying horizon to MSC though.

I do have a tapping fixture from MicroMark which helps with using small taps.

http://www.micromark.com/MICROLUX-TA...TURE,8363.html

[Bodyman]

i just bought this. weighs about 10 pds. received it yesterday.
http://www.littlemachineshop.com/pro...2898&category=

[Espeefan]

I buy my taps from McMaster-Carr too. Sometimes you are limited on the coatings they have available, depending on the size, but one thing I have noticed is that the black oxide or oxide over nitride coatings really help in aluminum. Those coated taps doesn't plug up nearly as easily as titainum nitride coated taps. There is nothing worse then having the tip of a spiral point tap plug with aluminum on you, while you are tapping. It cuts good threads on the way down, but as you back it up, it tears the threads out, which you just tapped. Even if you are especially careful with backing the tap out every one turn in, and use plenty of good oil, it can still happen. Once the tap is plugged, it's junk. Aluminum tends to weld itself to the tap.

[pugs]

I have rescued several taps plugged with aluminum with Red devil lye and water. Takes some time but it won't hurt the tap at all.

[Lil Giants]

I carve the aluminum out of the tap with a sharp #11 knife.

[dirtpusher9]

What dies work best on stainless? I'm going to have to buy a new set of tap and dies, mine are old and worn, but really looking for something that will work on a range of materials so I don't have to buy a bunch of different types.

[Izzy]

I like the MSC web pages - do a quick search for what you want - " thread die" then click on the page llink for an item - them scroll through the pages - they do a nice jov of catogorizing and explaining the coatings and such as compared to what material you might have.

give it a try!

[pugs]

I don't do much with dies, but as Izzy said just page though the MSC catalog pages and read the descriptions of the different styles and coatings.

[JAMMER]

If you put some ATF on the tap and the drill you use it and wipe the chips off after each hole. Another thing don't try to go to deep with a drill all at once. They have spiral drills for aluminum also. Ed

[Espeefan]

Since we are on the subject of taps, I was just wondering if anyone uses, or has used roll taps? It seems they might be one of the best ways to tap blind holes, since they don't make any chips at all.

[pugs]

roll taps = form taps which is the bulk of what I use

Just remember that a larger tap drill size is need as they are not cutting metal away but rather displacing it into the shape of threads. There are several places online that list the proper sizes as well as alot of new drill charts are including them as well.

[Espeefan]

Do they work better then the typical fluted thread cutting taps? How do they compare? Easier to turn, easier to break, require any back turning, or anything like that? Still need thread cutting oil? Are the threads better with roll taps? I heard they are supposed to be, but I have never used one. Just looking for advice on using them and any tips or tricks.

[pugs]

They work easier.
Stronger tap that is harder to break as there are no flutes (although some will have 1 small flute in them, but it is for cutting fluid to escape from a blind hole)
No back turning required just turn in till your through or to the bottom.
Still is nice to use some tapping fluid.
Threads are stronger as the grain pattern of the formed threads is more like that of a forged part.

I use them mostly in aluminum, have started to use them in steel as well with very good results. About the 2 biggest issues with them is that they require a larger tap drill size, and because they are displacing the metal you can not go back and redrill again deeper as you will be removing part of the threads. Also because they displace metal, typically have to chamfer the hole a bit deeper as the first thread will be pushed out above the surface slightly.

[Espeefan]

Thanks Jeff. I can easily live with doing deeper chamfers. Especially since they seem to be so much better and easier to work with.