Need Help!- Engraving Grade 50 Sheet Steel

[racecraft]

I'm trying to engrave our company logo into a piece of 3/16" grade 50 sheet steel.

Here is what i have:

Haas Tm-2 Mill
4,000 max rpm

I have a .0625" 2-flute ball nose cutter that is ALTIN coated and i am trying to pencil engrave into the plate .015" depth of cut.

I am flooding it with coolant.

My linear feedrate is 1.00 IPM and plunge is .75 IPM, I am maxed with the spindle at 4,000 rpm.

My tool is lasting about 5 minutes worth of cut time and my finish is HORRIBLE!

Where am I goin wrong? Please Help.

[sambo67]

are you using carbide or hss

[racecraft]

i am using carbide.

[sambo67]

try using a multi flute endmill . on steel the more flutes the better.Also because you are using the tip of the radius you do not have any chip clearance, therefore your endmill will try and load up.Remember. this type of cut you are climb and conventional milling.try using smaller depths at least a finish cut of about .005 you also need to ramp in ball nose endmills do not like to plunge and plunging will dull the end flutes.you also may want to speed feedrate up to about 4.0 IPM

[racecraft]

I will give this a try.

I did also try a solid carbide 60 Deg "V" engraving tool. This didn't seem to help at all. They wore out just as fast and were about 5 X's the cost of the ball nose.

I have another part running right now but as soon as that is done i will try your suggestions and post how they worked out.

Thanks so much for the help.

[racecraft]

Nah.... still not running very smooth. sambo67, your advice helped, but i still only made it through 1 1/2 parts per tool.

Not a big deal.

We'll just take the hit and switch to some 1018 CRS bar stock. That should do the trick.

Thanks for the help!

[diecutter]

Originally Posted by racecraft I will give this a try. I did also try a solid carbide 60 Deg "V" engraving tool. This didn't seem to help at all. They wore out just as fast and were about 5 X's the cost of the graving cutters. Often a single tip lasts for hours. I cut manually at approx. 3 ipmball nose. I have another part running right now but as soon as that is done i will try your suggestions and post how they worked out. Thanks so much for the help.

racecraft, I engrave in die steel every day with 60 degree carbide (split point) en and at about 8000 rpm and use a flood of heavy sulphated cutting oil only at the engraving area. Your depth of .015 is right on for good results.

My results are very crisp with the v- bit and rely on the relief angle being correct (25 degrees), and the proper amount and angle when tipping the cutter. My cutters are not that expensive at under $10 each for double ended .125 shank diameter, considering they can be resharpened in a couple minutes in my Deckel SO tool grinder as many as 20 times each end before needing replacement. Hope this info helps.

[diecutter]

racecraft, If you don't have any success switching steels, send a scrap of that grade 50 steel and your logo file and I'll be able to find out real quick whether a split point is the right tool to use. I'm not familiar with grade 50, but have engraved most high alloy die steels without a problem.

[racecraft]

That could maybe be a plan. Where are you located and how much would it run me to have you try something like that?

Remember: We are limited at 4,00 RPM and i would like to go .015" deep in one pass to keep cycle times to a minimum (which is still a long one)

[DareBee]

The problem with the 50W is the hard scale on the surface.
I have engraved in many steels (tool steel as well - occasionally).
I use a $2 centerdrill with good results.
I personally wouldn't expect any better tool life out of that hot rolled.
I usually engrave 8 - 10 thou deep, 8500RPM 15IPMish.

[racecraft]

DareBee,

This is grade 50 but the material is "pickled & oiled" meaning it has been de-scaled. It is still hot-rolled material. Therefore, i think a lot of the problem is the tool is running into "hard" spots in the material. The material is not consistent at all.

On the other hand, are u talking just a HSS #2,3,4 etc. center drill?

Thanks.

[diecutter]

Originally Posted by diecutter racecraft, If you don't have any success switching steels, send a scrap of that grade 50 steel and your logo file and I'll be able to find out real quick whether a split point is the right tool to use. I'm not familiar with grade 50, but have engraved most high alloy die steels without a problem.

racecraft, I looked up grade 50 steel and it appears it was originally designed for stressed structural members on ocean oil rigs. Most likely it will be engravable with a split point. If I could see the logo size and general shape I may have some tips on cutting it even if nothing is sent to me for testing. My offer was simply one company helping another through CNCzone with no cost involved. If you want me to try engraving a sample PM me and I'll give you info to ship it.