Good drill bits

   / Good drill bits #1  

Garandman

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Been using a variety of Harbor Fright and Home Depot purchased drill bits. Then had to drill some stainless fixtures and learned how poor they were.

What is a good fractional drill bit set, 1/64th to 1/2"? Do cobalt steel bits hol up better than Titanium nitride?
 
   / Good drill bits #2  
Check with a local industrial supply to see what they have. Good sets like Chicago-Latrobe will be expensive.
Cobalt will generally hold up better than TIN. The secret to drilling stainless is slow speeds, high pressure, and lots of cutting oil to keep the bit cool.
 
   / Good drill bits #3  
I learned my lesson a long time ago with stainless steel...take it to the machine shop and have them punch the holes on an iron worker. So much less aggravation and frustration.

Nothing short of diamond tipped bits work on stainless, "efficiently".
 
   / Good drill bits #4  
I found out that a small pilot hole helps drilling stainless. We always used liberal amounts of kerosene as a lubricant with both bits and hole saws. Even high grade bits have a hard time. Several holes and they are dull, hole saws are usually one time use if the stock is thick. A drill press with steady pressure woks better than hand held drill motors. I retired from the trade before plasma cutters were common. Does anyone have experience using that process on SS?

Ron
 
   / Good drill bits
  • Thread Starter
#5  
I learned my lesson a long time ago with stainless steel...take it to the machine shop and have them punch the holes on an iron worker. So much less aggravation and frustration.

I got the pilot holes drilled (using a small drill press) and some of the larger ones. Think the speed was right, and used cutting fluid.

These are the bits I plan to buy unless anyone suggests something better.
29-piece-cobalt-m-35-metal-index-drill-bit-set-341.jpg


29 Piece Cobalt M-35 Metal Index Drill Bit Set - Tools - IRWIN TOOLS
 
   / Good drill bits #6  
I got the pilot holes drilled (using a small drill press) and some of the larger ones. Think the speed was right, and used cutting fluid.

These are the bits I plan to buy unless anyone suggests something better.
29-piece-cobalt-m-35-metal-index-drill-bit-set-341.jpg


29 Piece Cobalt M-35 Metal Index Drill Bit Set - Tools - IRWIN TOOLS


The Irwin Cobalt M-35 sets are decent.
I have two sets, and they have held up well, though I only give them very occasional use.
You might want to also consider a "Drill Doctor", if you use your bits a lot.
 
   / Good drill bits #7  
Stainless is tough on bits. Oiling them helps and so does drilling slower. (less down force) Using Cobalt alloy bits may help but if it was me, I'd just assume that bits will be tore up doing this project. You didn't say the size holes your doing but pilots holes will certainly help as well.
 
   / Good drill bits #8  
Maybe I have been lucky but I so far have not had problems drilling stainless using good American made drill bits, slow speed, high pressure, and cutting fluid. Fast speed and the bits are toast.

Ken
 
   / Good drill bits #9  
Maybe I have been lucky but I so far have not had problems drilling stainless using good American made drill bits, slow speed, high pressure, and cutting fluid. Fast speed and the bits are toast.

Ken
This is where Id focus. ^^^
Garandman, since you have a drill press [and therefore good control] the cobalts are an option. But quite expensive as a set. You may want to look at buying just the sizes you need:​

McMaster-Carr

They will generally have the best quality bits in all types. Standard black oxide coated HS steel is rated for Stainless​
Are your holes being made in sheet metal?

BTW, I have found that Chinese bits are soft. Even the TiN coated dull readily when drilling Gr8 steel, Whereas std American black oxide holds up.​
 
 
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