Drilling a truck frame

[deeretails]

I need to drill several holes in a truck frame. The issue is it's a double frame truck with some rust jacking between the rails. As soon as a drill bit hits the rust it's done for, needs sharpening. Anybody have any tricks for drilling in this situation? The final size of the hole is 5/8, I drill in about 4 steps starting with a 1/8 bit.

 

[chevytaHOE5674]

Mag drill with a good annular cutter always does the trick for me.

 

[deeretails]

I have that option, but was afraid the rust would ruin the cutter just like it does to a drill bit.

 

[Steve@Advance]

Probably not the rust, but a hardened frame.

Really not supposed to drill or weld them, but a mag base drill and a carbide drill bit will get through. Carbide is extremely hard but also unforgiving for chipping and breaking!

 

[chevytaHOE5674]

I have chipped a cutter a few times hitting the uneven rust. But I've had better luck that way then with a twist drill. Not sure there is an ideal solution.

 

[roy prins]

We use to drill truck frames with a hand drill it was a c clamp sort of thing with a drill chuck and a crank to turn the bit -- it was slow but never killed a drill bit -- by turning by hand the bit never got hot -- we drilled leaf springs just to show it could be done !! Roy

 

[bmack95hd]

Yep, Mag drill is the way to go if available.

 

[used red MN]

Tapered reamer drill bits work great for that, see link. That is just an example Grainger has them. I used to work in a truck shop for a large bakery and that is what we used. In my opinion drilling with an 1/8 in. bit is a waste of time. In my experience 3/16, 7/32 or a 1/4 in. is best for a starter.
Example bit

 

[John Garner]

Sounds like a Cole drill.

 

[504]

A mag drill is the way to go. As long as you only drill the rail, and not the flange drill away!

 

[kcm.MN]

Have you considered a hole saw? There are carbide hole saws that have multiple teeth, so even if one or two break off, the rest continue getting the job done. Can buy just the 5/8 size you need, rather than a whole set.

Check here for an example:
https://www.amazon.com/ASNOMY-Tungs...+carbide+hole+saw,aps,282&sr=8-1&th=1

 

[Russ from MN]

I think this guy drilled the frame! I took this photo off YT a couple of days ago!

 

[Mike M]

When I worked at the Navistar Truck dealership the one service guy that did all the frame work always requested a new drill bit and a bottle of Curtis cool cut before starting the job.

 

[john in la]

I would be more worried about the rust than drilling some holes. Hopefully you are not adding holes to bolt the frame together because the rust is pushing them apart.

 

[Ultradog MN]

Your photo is way off base.
I don't know what was the cause of the problem in the photo but FYI, truck frames are drilled all the time.
As said by others, use a mag drill - a big one will be harder to handle but the speed will be slower. You can rent one at most equipment/tool rental places.
And don't by China bits!

 

[guido]

deeretailes,

My suggestion is to use reamer drills, and grade 8 hardware.

The unthreaded portion of the cap screw should be flush on the opposite side of the cap screw head,


Guido.

 

[BarnyardEngineering]

The biggest problem is people spin the drill bits way too fast. They take their 1/2" Milwaukee, chuck a 5/8" bit in, put it on high, and go to town.

You've got no control, and you're getting the bit way too hot by running it so fast. Even on low these hand drills spin too fast. You need 100-250 RPM, not 600-1200.

 

[Bruce(OR)]

You can drill the sides of the frame just not the top or bottom. That will structurally weaken it.
YMMV

 

[rlp in Co.]

The only way to stop rust jacking is to take the frames apart and remove the rust and repaint it and put it back together!

 

[dpendzic]

I agree --- as close as you can to the neutral axis

 

[the tractor vet]

We have drill a few holes in truck frames . When my one friend and bought two brand new I H 4300 eagles he and i did all the install of the Fifth wheels 1/2 fenders , wet lines and wet line tanks . We borrowed a mag drill and went to Ohio twist drill and bought our first set of new drill bit . We had 5/.8th and 3/4 holes to drill and LOTS of them we ran a 5/.16 starter and straight to the 5/8ths and 3/4 . The dealership had a big dril mounted ona roll around cart that they chaind to the truck when drilling and there first holes were 1/2 in holes then used a reamer for a true to size hole then the proper frame bolts that suck into the holes tight . Same thing we used . The Mag drill we used did not like the reamers as not enough power . Yea we tried with my heavy 1/2 inch drill but if it snagged it would wrap you up .Like said below i would be really worried about the rust between the two frames . DOT does not like rusty frames.