Shelby Drop PITA
08-25-2012, 09:12 PM
#1
2nd Gear Member
Thread Starter
Join Date: Jun 2009
Location: North Georgia
Posts: 207
Shelby Drop PITA
Did the drop on the '68 today......wow.....I did not anticipate what a PITA drilling those holes would be!!! Broke several drill bits and THEN ended up buying a new and bigger drill!!!!
Hey........but I DID get a new power tool out of it, right? LOL!!
Hey........but I DID get a new power tool out of it, right? LOL!!
08-26-2012, 12:43 AM
#4
4th Gear Member
Join Date: Aug 2008
Location: Goodyear, AZ
Posts: 1,674
I purchased a new bit and pattern from a vendor on this sight. I have used the same bit for several cars and it has been flawless.
Did you start with a smaller bit and work your way up, or just go for it?
Did you start with a smaller bit and work your way up, or just go for it?
08-26-2012, 08:00 AM
#5
2nd Gear Member
Thread Starter
Join Date: Jun 2009
Location: North Georgia
Posts: 207
Several times, as I went through the larger bits, the bit would bite hard into the steel and snapped the drill out of my hands!!! Wrenched my shoulder rather severely during one episode.......
What is this THREE layers of steel we're drilling through doing this mod?
08-26-2012, 12:26 PM
#7
3rd Gear Member
Join Date: Aug 2009
Location: Michigan
Posts: 516
Titanium coating doesn't help much. It has to do with the hardness of the metal versus the hardness of the drill bit. Most drill bits have a rockwell hardness around 65-70 and if the metal you're drilling through heat cycles a few times as you're drilling (Cools when you rest) then it gets harder as you go. Titanium coating wears off and leaves you drilling into metal with about the same hardness as the bit. This causes the drill bit to wear instead of drilling through the metal.
So when buying drill bits find out the hardness of the bit, not whether or not its titanium coated. Good hardened drill bits will last longer even if they aren't coated. You can get good drill bits at an industrial supplier like McMaster or WWGrainger(They also have cheap ones). This normally doesn't include anything at Home Depot, Lowes etc... One trick is to repoint a concrete bit becasue they have a hardness in the range of 120-140. I've done this to drill out axle flanges that have a hardness of about 95.
So when buying drill bits find out the hardness of the bit, not whether or not its titanium coated. Good hardened drill bits will last longer even if they aren't coated. You can get good drill bits at an industrial supplier like McMaster or WWGrainger(They also have cheap ones). This normally doesn't include anything at Home Depot, Lowes etc... One trick is to repoint a concrete bit becasue they have a hardness in the range of 120-140. I've done this to drill out axle flanges that have a hardness of about 95.
08-27-2012, 09:16 PM
#8
2nd Gear Member
Thread Starter
Join Date: Jun 2009
Location: North Georgia
Posts: 207
Titanium coating doesn't help much. It has to do with the hardness of the metal versus the hardness of the drill bit. Most drill bits have a rockwell hardness around 65-70 and if the metal you're drilling through heat cycles a few times as you're drilling (Cools when you rest) then it gets harder as you go. Titanium coating wears off and leaves you drilling into metal with about the same hardness as the bit. This causes the drill bit to wear instead of drilling through the metal.
So when buying drill bits find out the hardness of the bit, not whether or not its titanium coated. Good hardened drill bits will last longer even if they aren't coated. You can get good drill bits at an industrial supplier like McMaster or WWGrainger(They also have cheap ones). This normally doesn't include anything at Home Depot, Lowes etc... One trick is to repoint a concrete bit becasue they have a hardness in the range of 120-140. I've done this to drill out axle flanges that have a hardness of about 95.
So when buying drill bits find out the hardness of the bit, not whether or not its titanium coated. Good hardened drill bits will last longer even if they aren't coated. You can get good drill bits at an industrial supplier like McMaster or WWGrainger(They also have cheap ones). This normally doesn't include anything at Home Depot, Lowes etc... One trick is to repoint a concrete bit becasue they have a hardness in the range of 120-140. I've done this to drill out axle flanges that have a hardness of about 95.
08-29-2012, 05:52 AM
#9
6th Gear Member
Join Date: May 2009
Location: PA
Posts: 5,232
08-29-2012, 09:14 PM
#10
2nd Gear Member
Thread Starter
Join Date: Jun 2009
Location: North Georgia
Posts: 207
I've never owned or used a "step bit".....not sure what it is.....but if I have to drill anymore holes in a shock tower, I'm getting one!!!