HSS tool bit questions.

May 19, 2008 9 Replies

posted to both amc & rcm



For our money players in AMC



How much are you using the traditional square ground lathe tool bits? If you are, are you using M2, M2Al, 5% or 10% cobalt? Do you hand grind, or use a surface grinder w/fixtures or attachments, i.e. radius dressers? Also for what purposes, e.g. special form tools, special threads such as acme or buttress, general machining where the material damages high $ carbide such as excessive scale or inclusions?



For everyone



If you are using square ground tool bits, how much difference [if any] can you tell between the generic import M2, the domestic M2 and the newer alloys like M2Al, and the 5/10% cobalts?



Specifically is the Armstrong M2 tool bit worth 3X to 4X [or more] than the import M2, or is this another "Starbucks?"?



Does anyone know if the "domestic" M2/M42 tool bits are actually made in the USA from "Mercan" steel, or are these just import M2/M42 tool bits repacked with a "made in USA sticker" on the box and a higher price tag?



Also, I am in the process of ordering some 3/8 and 7/16 bits for my new shaper. I am shocked -- shocked by the jump in M2 prices from the last time I bought [for some suppliers > 250%]. Are all HSS tool prices rising like a rocket?


Unka' George [George McDuffee]



------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?



Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).


Crucible CPM T15 for form tools for the screw machines OLD ones. Bought a bunch 25 yrs ago, don't know if you can get T15 anymore. Grinds like butter & will run & run (with OIL) . Also have 1/2-3/8-5/16-1/4" bits.

======== Thanks for the info.

T-15 tool bits are still available. For example

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high priced spread
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I will add T-15 to the what tools are you using list.

FWIW -- T-15 specifications

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The only T-15 tool that I use [that I know of] is a P type cutoff tool from Somma [p/n BL844V] that fits my shop-made rear mount [upside-down] cut-off tool holder. Works well and easily cuts hard material such as the salvage 2 inch diameter pump shafts that I use for bar stock. I generally have to use brazed carbide for turning this stuff, but may get a T-15 tool bit and try that.

see

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for details of the holder.

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

============= Thanks for the offer.

The absolute max for the tool post on my Atlas 7B shaper is 7/16. I got to checking the back of the tool box drawers, etc. and found several 7/16 sq M-2 tool bits.

Hope someone else is in a position to use the larger sizes.

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

Only use them on occasion, have not bought any in years.

I do have a bunch for sale 5/8" and bigger, M42, T5 and T15.

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make offer plus shipping.

Thank You, Randy

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F. George McDuffee wrote in news: snipped-for-privacy@4ax.com:

Pretty much never use them. They simply aren't cost effective on the type of equipment we have. Even if they were free.

In fact, we use mostly carbide for drilling as well. The exception being small holes in brass and aluminum where the SFM can't be acheived.

Our least expensive lathe is $150,000.00 well equipped and ready to run. The most expensive can cost over $500,000.00. Figure the dollars per hour you need to generate and you can't afford to be messing with HSS, it's too slow, too labor intensive, and doesn't perform. We rarely use brazed carbide, and almost never use uncoated carbide inserts except for aluminum. But even in aluminum it would be a highly polished special prep insert. If there is sufficient SFM and the job is higher volume, PCD would be the 1st choice for Aluminum.

This is all on higher end CNC Swiss type and conventinal fixed head lathes. If I were running an engine lathe at home HSS would be my first choice. HSS really has few applications in the real world anymore. At least not on high performance CNC lathes. In the tool room you could probably make a case for it though.

We have a Nardini 14x40 in our "tool room" (I use that term loosely) and I was turning out some bushings a few weeks ago using an insert tool. I was using an insert tool mainly because we have loads of them along with all the inserts you could ever want. As the red hot chip were pelting me I thought I either have to get one of those plastic sheilds on a magnet or buy a HSS tool or two.

Speaking of hot chips, I set our booth on fire at a trade show in Mexico City using a carbide insert tool on a big engine lathe. The guy demonstrating the Harrison lathe had to leave early and I stepped in and did a few demos on it.

One customer was concerned about rigidity. To show the rigidity and power of the machine I stood a nickel up on edge on the compound, took a 1/4" DOC at a 0.015" or 0.016" per rev feed rate. I was running around 750 SFM in 1018 steel using an insert tool. The chips were flying off like popcorn. The nickel didn't move or tip over. The customer was impressed and after the cut as we were standing there chatting and I smell something burning and my feet are getting hot. The carpet was on fire. We got it put out but not before it made lots more smoke and stink.

The guys running the show weren't real happy.

Modern ultra fine micrograin carbide will hold an extremely sharp edge.

Anyone have any Stellite they would care to sell me?

Gunner

Can you not buy what you want. I bought some Stellite, can't remember the grade, for cutting blade edges a few years ago. The UK depot is about 30 miles from me.

Used it many years ago, tough to grind, I'd follow the grinding suggestions on the above web site.

Tantung and Stellite are either similar or the same, as both are cast alloys.

Thank You, Randy

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