Drilling speeds and feeds for tool steels D2, H13, O1, S7, W2

[squinn2185]

I’m not new to the industry but I am new to machining tool steel. I’m not having too much trouble turning and boring the above materials, I’m even managing to get decent surface finishes on the turned surfaces. However I am having a lot of trouble drilling all of the above materials. I am using solid carbide and indexible carbide drills of various sizes and I’m breaking them constantly. I have been using 100 sfm and feeding at .007 a rev for the D2 material. I’ve been using 230 sfm and feeding at .006 a rev for the H13, O1 and S7 material. Im also using flood coolant because I don’t have a through coolant option on my machine. Machine is a 2001 mazak integrex 200sy. Should I be using a lower surface footage and a higher feed? Or vice versa? Everything I’m trying seems to have the same result. Any help would be appreciated.

Thanks

 

[Houndogforever]

How are you holding them? What diameters are you drilling?

I'm using some Nachi SG-ESS drilling a 1.98mm hole in D2 and I'm at 35sfm and .002ipr. These are not carbide drills.

Most carbide drills have recommended speeds and feeds, what brand are you using?

 

[eKretz]

Investigate your cutting edges for failure mode. Are these tool steels in their annealed state? Not specifying that makes it impossible to give any meaningful advice as to cutting speeds and/or feeds.

 

[squinn2185]

Investigate your cutting edges for failure mode. Are these tool steels in their annealed state? Not specifying that makes it impossible to give any meaningful advice as to cutting speeds and/or feeds.

Yes all materials are in their annealed state. I check my flutes and edges after every five pieces for ware and or breakage. Still get same results after about 30 pieces have been machined.

 

[eKretz]

Yes all materials are in their annealed state. I check my flutes and edges after every five pieces for ware and or breakage. Still get same results after about 30 pieces have been machined.

If you are monitoring your edges you should not be getting any breakage. Are you trying to say that there are no visible indications of wear or breakdown at all through nearly 30 parts and then the inserts are breaking out of the blue? Maybe try another brand of insert if that's the case. What brand are you using?

Also, for annealed material your SFM is WAY low, IMO. I would not be any lower than 250, and very possibly higher yet. Start the feed at .005" and adjust as you monitor the edge.

 

[DouglasJRizzo]

@squinn2185 The feedrate seems a bit high.
I'd feed at about .003 per rev.

 

[eKretz]

I also just remembered that you mentioned no through coolant. May need to drop SFM just a smidge due to that. Watch the edges.

 

[Mtndew]

what brand are you using?

Not just the brand, but the style is needed to give him accurate numbers.
I don't know why people ask questions but never give info.

 

[guythatbrews]

How are you holding them? What diameters are you drilling?

I'm using some Nachi SG-ESS drilling a 1.98mm hole in D2 and I'm at 35sfm and .002ipr. These are not carbide drills.

Most carbide drills have recommended speeds and feeds, what brand are you using?

Not just the brand, but the style is needed to give him accurate numbers.
I don't know why people ask questions but never give info.

Hear, hear! It is pretty tough to provide anything but the barest help without more detail.

All tooling manufacturers have free tech support by phone, online, or both. Unless you are getting your tools from the hardware store. Utilize that knowledge base. The quality of support varies, but you get help in real time. The give and take between you and the tech can flesh out all the details.

 

[Dan from Oakland]

If ya look up the machineability of annealed D2, it is about 27. If ya look up Carpenter S7, they list that at about 70. So you can't lump all tool steel together. A2 has a higher machinability rating as well. Good rule of thumb is mild steel like 1018 can be machined pretty well with HSS tools at about 100FPM. The machinability rating of 1018 is about 80%. Scale things from there or download a machineability rating chart and stick it in your tool box. I use 400 FPM for a WAG in mild steel if using carbide. Cool trick- 400*dia in inches will give you the rpm for a tool or workpiece at 100FPM or thereabouts.