Re: Drilling on thin metal sheet

di lang smooth ang feed pero nagawa nyang i correct yung tri oval ng butas

disclaimer lang
safety first lalo na sa pag grind ng bit wag nyong gagayahin yung angle grinder na gaya ko sa bench grinder ang gamitin nyo.
HInde ako liable sa mga action nyo.

Re: Drilling on thin metal sheet

Bro did you check for any run out on the drill bit while mounted on the chuck? At first it was my suspect but now the modified bit made me think otherwise.

Drilling on thin metal sheet

Ran out sa chuck is not an issue its the design of the bit
Normal bit tend to draw the chip from the center throw it outside 60 deg tapos baon na uli sa makapal walang problema kasi mag change angle pagreach ng mid part ng bit

Kaya yan naisip kong gaya ng principle ng hole saw

Ito pla detailed info may gumawa na pala

http://qrpbuilder.com/downloads/sheet%20metal%20drills%20a.pdf

Sent from my iPhone using Tapatalk

Re: Drilling on thin metal sheet

I have experienced this kind of results drilling holes on 1/8 or 1/4 steel plates.

I think its the tip of the drill when it starts to get dull that is why there is some sort of run out or wandering producing ovalish holes, hinde na balanse yung talim sa gitna, good thing I really don't
need perfect holes that time for the project, just needed to fit some bolts to tighten somethings to
the plates.

I suppose we should make it a habit and see to it that drill bits are properly tuned and sharpened before or during drilling to maintain at least perfect holes. IMHO !
Unless otherwise the bit is not centered on the drill chuck when mounted. :dunno::whistle:

Cheers and best of luck !!

Re: Drilling on thin metal sheet

I'll keep this info in mind when I drill holes on 1.5mm square tubes. Using 135 deg split point bits get me inconsistent results. Some are round and at times oval.

Re: Drilling on thin metal sheet

na experience ko ng mag dril ng maraming butas pero single plate matagal ang tri oval ang butas di perfect circle
so nag experiment ako ng batch drilling - (multiple plate clamp together)

Yes, mas madali talaga because you transfer all DP force into the
drillbit's shearing action, rather than deforming the stock (semi
related ang sacrificial support block sa wood, except tearout sa
backside ng stock naman ang iniiwasan). Ang lugi na lang is the
last sheet at the bottom of the stack.

More importantly, stabilized ang stock wrt the DP table. Kahit na
merong clamp na gamitin sa iisang thin sheet, merong vertical
vibration ang sheet relative to the DP table and therefore the bit.
Naglilikot ang stock, so mas posibleng maglakbay ang bit.

so naisip ko imbes na sa gitna ang simula ng pagbubutas gagawin ko na lng pilot yung gitna at tulisan ang gilid ng bit

Kahawig na ng mga bradpoint ko, hehe.
The reason that drillbit profile isn't commercially popular for steel
may be that severe stress is focused on three points, which then
dull and/or lose temper very quickly... but let us know how it fares,
longterm.
🙂

I think its the tip of the drill when it starts to get dull that is why there is some sort of run out or wandering producing ovalish holes, hinde na balanse yung talim sa gitna,

Exactly the same experience/impression here.
It can't be issues with the DP itself, because swapping in a fresh
bit cures the problem IME.

JM2P, YMMV, etc.

Re: Drilling on thin metal sheet

ever tried using a pilot hole? or a water soluble cutting oil to keep the bit sharper longer.

Re: Drilling on thin metal sheet

ever tried using a pilot hole? or a water soluble cutting oil to keep the bit sharper longer.

Butch mas mabilis mag dull pag ni lulube ko ng ng cutting coolant (from my coldsaw) or oil
and yes Im using pilot hole 1/8 " bago 10mm

Guys kahit bnew yung bit nyo basta manipis i dri drill may 3 sides pa rin mas obvoius lang pag dull na

Kahawig na ng mga bradpoint ko, hehe.
The reason that drillbit profile isn't commercially popular for steel
may be that severe stress is focused on three points, which then
dull and/or lose temper very quickly... but let us know how it fares,
longterm.

yung bradpoint mo is pang wood no?
well paisa isa lang naman feed ko sa kanya so di gaano loaded

yung orig bit pa rin ang pang batch drilling ko

Re: Drilling on thin metal sheet

Maybe a little OT question here :

Since most of us here uses the usual hardened drill bits for thin and thick carbon steel, may I ask if there's such special drill bits used only for stainless steel ? I find it so difficult to drill holes on SS flat bars/stocks even though a pilot dent has been made with a center punch. :confused:

Thanks in advance !

Re: Drilling on thin metal sheet

From what I've read around, cobalt drill bits are suited for hard metals like SS and cast iron.

Here's a brief explanation:
http://home.howstuffworks.com/cobalt-drill-bits.htm

Re: Drilling on thin metal sheet

I purchased these before but was not happy. Irwin Cobalt M-35

http://www.amazon.com/Irwin-Industrial-Tools-3018002-29-Piece/dp/B000BO9JMK/ref=sr_1_1?ie=UTF8&qid=1404890273&sr=8-1&keywords=irwin+cobalt+drill+bit+set

However I have not tried the Irwin Cobalt M-42 yet.

http://www.amazon.com/Irwin-Industrial-Tools-3018002B-29-Piece/dp/B000EB641Y/ref=sr_1_3?ie=UTF8&qid=1404890273&sr=8-3&keywords=irwin+cobalt+drill+bit+set

I switched to Norseman and have no problems drilling even stainless steel.

http://www.amazon.com/Norseman-29pc-16-1-Black-Gold/dp/B00627C8ZU/ref=cm_cr_pr_product_top

Re: Drilling on thin metal sheet

yung bradpoint mo is pang wood no?

Precisely the point I was trying to make. 🙂
We don't see bradpoints for steel, likely for the reason I just gave.
Great to hear your modded bit is holding up.

I switched to Norseman and have no problems drilling even stainless steel.

http://www.amazon.com/Norseman-29pc-16-1-Black-Gold/dp/B00627C8ZU/ref=cm_cr_pr_product_top

Kulam.

Re: Drilling on thin metal sheet

We use diluted water soluble oil or sometimes dishwashing soap n water to cool the bit and make them lasts longer on stainless stèel.