I want to drill a new hole in my Gen3 dipstick to calibrate it to the Holley pan.
I used a punch for a pilot, cutting oil, but I'm not making a dent.
I tried several different bits, the titanium with nitrate coated, but they break before doing anything.
Not helping that it's a tiny hole, maybe 3/32 or 1/8" max.

What's the secret, shouldn't be this hard / difficult.

Stainless steel? If so some grades of that stuff can be super hard. Scribe a line instead?

Small file or mini grinder

the last two suggestions is what i normally do

Me personally I would mill it with a carbide end mill. But short of that, a carbide drill if its really tough, but at minimum cobalt drill. If I am drilling stainless, cobalt drills are where I start.

Start with the smallest drill bit possible and work up in small increments.

"Nitrates" are food preservatives. "Nitriding" is a hardening process involving nitrogen and is typically used on drills and end mills. Mark is spot-on in his reply and suggestions.

"I tried several different bits, the titanium with nitrate coated, but they break before doing anything."

Carbide drill bit will drill no prob. A notch with a file works also.

Thx for the inputs, I’m giving up on drilling it.
Maybe try and make a scribe/notch with a Dremel.

make sure you drill is not in reverse.................. [ask my brother about that, and he says bad words...... ]

Years ago i took my freshly sharpened drill bit set to a buddy's house to help him work on is car. After a few minutes he says these bits are a dull as a flat nosed punch. I wander over and said they are right hand drill bits
he says HUH?
I said if you want to drill holes with the direction your drill motor is turning you'll need LEFT had drill bits.
He asked what do my hands have to do with it? He never did live that one down 🤪🤣🤣

Right up there with my ex dip💩 employee that installed a brand new Bi metal bandsaw blade stating It was a POS and I got ripped off as it was dull. Helps to install the blade with the teeth the right direction.😉

They walk amongst us 🤪🤪🍻

By own experience I know that "spark erosion cutting" (suggested translation) works. In simply words "reversed welding". But you may have to look around to find someone who has the right equipment.

I agree, but....

Everyone needs a set of left hand drill bits.

I heard for years from old timers how left hand were handy for removing broken off right hand thread bolts but held off buying myself a set.
When I finally did and had an occasion to try them, the old timers were right!

I also learned if you had a small battery hammer drill, very briefly engaging the hammer function helps in removals using left hand bits.

I have several types of extractor sets, all have strengths and weaknesses.

Have you heard NASA is in a “stuck screw pickle“ on their asteroid sample container?
Kicker is it is inside a super secure glove box, two screws stuck out of 32
( in the 1990s I had to mill flat rare earth carbide samples inside a dry nitrogen glove box so I feel their pain)

https://bobistheoilguy.com/forums/threads/nasa-cant-get-two-screws-out.375262/

https://wonderfulengineering.com/nasa-is-reportedly-struggling-to-open-its-asteroid-container/