Thread milling

[kstrauss]

TurboStep, have you found an affordable source of single pitch (multi-tooth) thread mills?

[gerritv]

I just today tested an M5x0.8 thread mill from Aliexpress. No big deal doing the Conversational, worked great in the delrin I am learning on. Used the Drill tab to locate the holes, milled the holes using a 2mm end mill (no 4.2mm stub drills yet), then the thread milling.

https://huhaocnctool.aliexpress.com/store/3362033 was the store I bought from. Bought 2 of M3, M4, and M6. I used the M4 one todo the M5 threading.

Aluminum next, then steel. Going down the list of skills to practice.

Gerrit

[TurboStep]

TurboStep, have you found an affordable source of single pitch (multi-tooth) thread mills?

In my language "affordable thread mills" is a contradiction in terms The most economical I've found so far are from Lakeshore or Maritool. The smaller ones in my photos are Swiss made (DIXI 1730) and cost $80 upwards.

I used the M4 one todo the M5 threading.

That sounds a little strange...
I checked out the link you provided but I couldn't find any metric thread mills. Do you have a part number?
Step

[Clive S]

I found these but the postage to the UK £35 https://www.aliexpress.com/item/1005...72474f078OgkRv

[kstrauss]

That is strange. It shows shipping to Canada is us$2.61. Did you perhaps choose to use DHL or EMS?

[metalmayhem]

onlinecarbide.com
these guys have reasonable prices on thread mills . I've been eyeing them but haven't given them a try yet

[Tigster]

Great info here guys, maybe I'll jump on board this weekend.
I use Rouge endmills and own a thread mill but haven't used it yet. They are USA made (I think Utah) and great prices if you want something from The USA. They are a small shop with some killer equipment..look for their shop walk through on YouTube.
https://www.carbidetoolsource.com/

[TurboStep]

I found these but the postage to the UK £35 https://www.aliexpress.com/item/1005...72474f078OgkRv

Starting from your link I finally arrived at what I was looking for:
https://www.aliexpress.com/item/4001...33a04bcf3lQ8PG
The G121007 appears to be suitable for M5 threads.
@Gerrit: Is this what you used?

Trying to look closely at the thread form they would appear to be ground to a point, but it's difficult to see, and the images might not reflect the actual part. If so, they will do the job, but the nominal diameter of the programmed thread may need to be adjusted slightly to compensate.

I just ordered one so I'll find out in a month or two
@Clive: Shipping to Switzerland was around $2.30 but the cheapest option for shipping to the UK was indeed £35!!! Is that perhaps due to the Brexit? If they work out and you're still interested we could possibly arrange something.
Step

[gerritv]

I bought the L126010 (https://www.aliexpress.com/item/1005001298358910.html). I couldn't get my head around using the multi toothed ones.

Attached some photos. The profile photo is at 20x. I'll be brave today and do some threads in aluminum/aluminium and then section it. I can go to 100x on my optical comparator.
The tips are definitely not pointed, there is a flat at the tip although with 73 year old eyes they do look pointed.

I will admit that when I ordered these I didn't look closely at the L, G et al variants. Most of my work will be in 6061 so the L series seemed a good enough fit. This is just a hobby for me so that often colours my choices, not into production or speed.

Gerrit

[kstrauss]

Gerrit, I'm interested in your comparator. Is it from a published design or something that you created? Can you provide any further details?

[gerritv]

It is a Nippon Kogaku (Nikon) 6, a Kijiji find last year for CA$250. It came with 10, 20 and 100x lenses. Welded up a mobile stand, at chair height for comfo operation.
Derek recently got a Jones & Lamson, similar size. They pop up fairly often. Shipping LTL from anywhere in Canada is quite reasonable.

Gerrit

[John Roberts]

Am I right in thinking that threadmills have a recommended diameter range that they should be used for. I imagine the clearance angles on these cutters are designed to cut threads little bigger than the cutter. Anyone thread cut internal and external threads which are of large dia. Lets say cut a 50mm dia thread x 1.5mm pitch in alloy. using a 10mm threadmill? I am curious as to the finish that can be achieved? I find this thread very interesting (pun intended!) and wish to gather as much info on this procedure before buying and trying.
I did look on aliexpress web site and most had ridiculous postage costs to the UK but after looking further they are available at reasonable shipping.

[jwatte]

Am I right in thinking that threadmills have a recommended diameter range that they should be used for.

Yes! For two reasons!

The first is that the mill won't fit into the clearance hole of a too-small thread.

The second is that the mill won't cut deep-enough threads of a too-large thread.

That being said, the range is pretty big. I think I have a .100, a .180, and a .250 and they cut anything from M3 to M12 (and similarly sized imperials.) Might go even higher than M12 but I haven't needed it to.

For M2.5, I use a Sandvik three-tooth that can really only cut that size/pitch, but it's great. That size is a little too small to screw around with micro mills.

You're also right that the trapezoidal shape of the teeth is slightly more acute than the thread form 60 degrees, because it "spins through" an arc of the thread wall. If you're making super-tolerance space-science stuff, you might want a mill cut specifically for the particular thread you're making, but for regular 6H/6G tolerance, seems to work for me!

cut a 50mm dia thread x 1.5mm pitch in alloy. using a 10mm threadmill?

You can cut that with a much smaller thread mill, the pitch is really what determines size tool you need. (That, plus stiffness.) The shape of the thread will be "better" the smaller the tool is, in general, as the overlapping arc between the thread and the tool is narrower. But you can take fewer passes, and feed faster, with a stiffer tool, so ... experiment!

[gerritv]

Speaking of Sandvik, here is their treatise on threading, for lathe and mill: https://tibp.blob.core.windows.net/c...48e5b7777a.pdf

Their books provide stellar educational material.

I will try to get the tip specifics from Huhao, they say to ask them for that if you need it. That would help determine the range of pitches and threads per cutter. My cutters are single tip.

[vmax549]

In a Pinch you can always grind down a tap to a single point mill.

(;-) TP

[Clive S]

@Clive: Shipping to Switzerland was around $2.30 but the cheapest option for shipping to the UK was indeed £35!!! Is that perhaps due to the Brexit? If they work out and you're still interested we could possibly arrange something.
Step

@Step:
It might be a mistake in the listings as there are other types there that are only about £2.50 postage.

Thanks for the offer.
Clive