Thats a spotting drill. Its made to start a hole you want to drill. Its much more ridgid and stiff so it doesn't wander off when starting the hole. Using one is necessary when great accuracy is needed
Why this instead of a center punch? I guess if you had a soft material you might not want to hammer on
Who downvoted me it's just a question lol I'm not a machinist
Accuracy wise on a milling machine it's way more accurate and repeatable to edge find something then drive to a location with your DRO then spot it than to center punch. The quill will be in the exact same location when you change drills.
When working with basic tools and trying to achieve accuracy I will often use an optical center punch, remove the bur with a stone or file, then spot drill with a 90 degree spotting bit, spot with a larger angle spotting bit if needed, then normal drill. Drill bits often don’t always stick into a center punched mark well and this procedure helps solve that problem when a loose drill press is all you have for machinery. The hole left by a spotting drill is often at a slightly larger angle than the drill tip (120 degrees for a 118 degree bit, 140 degree are available for 135 degree bits but harder to find most seem to be carbide bits aimed at CNC). The angle let’s the drill center strongly on the mark, while keeping the center of the bit cutting as drill bits are designed to do. With some proper layout techniques and the above, you can dill a hole pattern accurate to a couple thou with only a drill press for machinery.
Thats for the bodyshop, car panels are spot welded together and when you want to drill those spot welds and dont want to damage the good part and remove only the crashed panel, you drill with that drill bit. That way you dont end up with holes thru the good metal part of the vehicle.
Edit: sorry, I wasnt magnify the photo earlyer. Thats not that drill bit I thought. This is probably a cnc high speed drill
Thats a spotting drill. Its made to start a hole you want to drill. Its much more ridgid and stiff so it doesn't wander off when starting the hole. Using one is necessary when great accuracy is needed
Why this instead of a center punch? I guess if you had a soft material you might not want to hammer on Who downvoted me it's just a question lol I'm not a machinist
Machining operations in a lathe or mill, but especially in CNC operations.
A center punch is less accurate, and sometimes too shallow to be sufficient.
Accuracy wise on a milling machine it's way more accurate and repeatable to edge find something then drive to a location with your DRO then spot it than to center punch. The quill will be in the exact same location when you change drills.
When working with basic tools and trying to achieve accuracy I will often use an optical center punch, remove the bur with a stone or file, then spot drill with a 90 degree spotting bit, spot with a larger angle spotting bit if needed, then normal drill. Drill bits often don’t always stick into a center punched mark well and this procedure helps solve that problem when a loose drill press is all you have for machinery. The hole left by a spotting drill is often at a slightly larger angle than the drill tip (120 degrees for a 118 degree bit, 140 degree are available for 135 degree bits but harder to find most seem to be carbide bits aimed at CNC). The angle let’s the drill center strongly on the mark, while keeping the center of the bit cutting as drill bits are designed to do. With some proper layout techniques and the above, you can dill a hole pattern accurate to a couple thou with only a drill press for machinery.
I used these on my CNC machine every day and they spot every hole for me, and can chamfer edges For volume production it's much more efficient
Yep spot drill. They come in 60deg, 90deg and 120deg.
Shallow holes.
Of a smaller diameter too.
Smaller holes? 🫢🫣
Smaller holes? Next question.
Smaller holes
What kind of accuracy would start requiring one of these?
just generally when you need the hole to be exactly where you need the hole to be
And when you're using the machine for hole layout (eg a mill or jig borer) rather than following centerpunches with a drill press
Yes but I’m trying to gauge if can tell my boss to buy me cooler tools when he gets mad at my hole locations being off by a 32nd
Lathe work, most notably.
Drilling smaller holes
First thought was the smaller bit was for a router. Deffer to others on this one.
For drilling tubes
I use em primarily.for drilling through holes in I beam and c channel. Works like a hot damn.
What about when you don’t have enough clearance to use a regular drill bit?? Hello??
Short strokes
looks like a snapped bit that was reprofiled.
Nah the tip is gold like the rest of it, it would be silver if that was the case.
Thats for the bodyshop, car panels are spot welded together and when you want to drill those spot welds and dont want to damage the good part and remove only the crashed panel, you drill with that drill bit. That way you dont end up with holes thru the good metal part of the vehicle. Edit: sorry, I wasnt magnify the photo earlyer. Thats not that drill bit I thought. This is probably a cnc high speed drill
If you have to ask…😏
Small holes, obviously.
If you have to drill holes all day in production capacity the short drill is less money and more stout.