help with 17/32 spade drill

[rowdygator]

im on a Monarch mill 17 hp motor, im burning up spade drills its got coolant thru holder and cobalt tip, im drilling 304 stainless ,.900 deep, any suggestions on speeds and feeds that would help??? i was running it at a speed of 582 and a feed rate of 3.2 with a .125 peck and it definetley didnt work , but i slowed it down to 60% speed and feed rate of 2.0 and a .05 peck and so far it went ok just slow, and i have to drill 36 holes then tap them. any suggestions on a proper feed rate and speed with a good peck would b helpful and yes i new to this progamming thing...

[Robert Ouellette]

how fast are you turning it? I would say around 50-75 rpm and flood it. or interpolate with a 3/8" endmill and call it a day. I would not even think of drilling that. I might predrill with 1/4" drill then endmill it.

[djstedman]

I would say 45-55 SFM so start around 324RPM Feed .005 IPR so 1.62IPM, No Peck and flood the hell out of it with the through coolant .. That's where I would start at least.. 304 can vary a lot though between lots of material.. though so might need to tweak it based on how it reacts

[rowdygator]

with this machine its only function is drilling and tapping, its turn table in c axis is so slow and it dont have an x axis. so i have to drill it we make pipe flanges, im thinking i dont ike soade drilling very much, plus i new to programming anyway, so im thinking it would b better to just use a iscar coolant thru crabide drill bit?? but what i had on hand was that spade drill, and slowing it down to around 320 rpm and the feed rate is now 1.8. flooding the hell out of it and so far its been 4 holes and its holding up. but if or when it fails should i run the Iscar over the spade??

[workmantm]

I run 304 Condition B here. The only way I've gotten drills to hold up is to run solid carbide and not peck. I drill half way thru, turn the OD and break the ID edge then turn it around and drill the other half and bore for finish size. We are not running thru tool. I tried everything including sending the parts out for gundrilling. That is the best I've gotten anything to perform in that material. Watch the pecking cause anything stuck down the hole will wreck your insert. I run Accupro 4X carbide drills at the given S&F. Don't have the chart handy at the moment.

[TFesta]

I use spade drills all the time. But I won't use the 17/32 on steel. It's too thin and can't take the pressure. Use solid carbide, no peck or a good cobalt one 40-50 SFPM.

[rowdygator]

thanks for all the input i ended up throwing the spade drill idea away and ran an Iscar coolant thru carbide drill bit and it ran perfectly. thanks again...

[crazy^millman]

Perfect and think of the money you made going in the direction.