Preparation of .505 tensile test specimens 3

[yupper56]

I am considering the purchase of a new lathe for the preparation of alloy steel .505 tensile test samples. Is any one familiar with the CNC "TensilKut" equipment.

 

[Goahead]

I was informed Tensilkut is excellent for preparing aluminum alloy specimens. But for alloy steels it would be better to check with the manufacturer if the hardness range you want to use will be machined properly.
You might be able to send them samples for machining and then examine them upon receiving them back.

http://www.welding-advisers.com/

 

[yupper56]

Thanks for your comments. I thought that someone might have used the equipment in their lab and could share some info. I have a copy of their brochure. We have always turned our samples using a marvel lathe, but was trying to upgrade. We run approximately 500 tensiles a month and have concerns regarding unit productivity.

 

[Carburize]

We have a small Mazak machine for this job - works on cast irons, ductile irons and quenched and tempered alloys up to about 400BHN.

 

[yupper56]

Thanks Carburize: I will run a search on Mazak. What is your prep time for a sample?

 

[Carburize]

yupper56 - We feed the machine with rough saw cut pieces about 1-inch square. With set up and centering it takes about 20-minutes to turn out a finished specimen from picking up the rough blank. At the high end of the hardness range tool wear can be significant and may require a tip change during the turning operation adding around 5-minutes.

 

[EdStainless]

imo The advantage of a small NC lathe over the TK machine is flexability. The TKs are fine if you are doing materials that are not too strong and there is not much variation.
If you have to accomidate a wide range of work then a lathe will be slower, but it will allow you to do more things.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[yupper56]

Thanks for the information

 

[NickE]

I used a tensul-kut for about a year to machine std .505 flats. It worked well on low alloy and low carbon sheets, including DDQIF and other really gummy steels. I've never cut Al alloys but it worked ok on 420ss at 54HRc, but the router bits went fast.

I figured that the two flute carbide wood cutting bits probably just were not up to the task, I think a better end-mill might work better, but the dang thing spins at like 20k rpm. And try and get kenna-metal or other end-mill manufacturer to suggest anything at that type of speed!

On Inconel X750 and Be360 the harder the better edge, but it wouldnt bee too hard for a practiced operator could get a good edge pretty easy.

The Tensul-kut manual machine can with a bit of practice hold the width variation to <.002" if they try, and <.005" with almost no trouble.

I could cut ~100 tensile bars (2" gauge) a day if they were 1008/1010 and other soft sheet material, especially if the thickness was <.100. The process goes much slower as the samples get thicker.

 

[yupper56]

We only use our lathe to machine std .505 specimens (~500 a month). A large percentage of the tests are around 125K tensile -- mostly alloy steels. It takes our lab techs ~5 to 10 minutes to finish turning a tensile test. We start out with a torch cut coupon 5"L x 9"W x thickness, rough saw a 1" square stick along the 9" dimension and machine the rd test. Base on comments so far, I'm beginning to think a std lathe probable will work the best for us. 15 to 20 minutes a sample is just to long.