Drilling out a tapered hole

[chevihemi]

I have been trying to search for some good info on the best way to drill out and slightly enlarge a tapered hole on some stock Toyota steering arms. I tried on one are but the hole was very jagged and not nearly tight enough for me to feel comfortable running a heim joint in it. I am looking to drill it to 3/4" diameter, which is about 1/8" or so bigger than the large end of the taper.

Are there any bits that will make this easier to drill out and acurate enough to run a bolt through for a heim joint. This will never be street driven as I am switching to full hydro steering.

Thanks for your help!!

[gte718p]

I'm probably stating the obvious, but of that size hole you need a good quality properly sharpened drill bit, relatively slow speed, and a very solid vice on a drill press or mill.

In fairly similiar situations I've had fairly good luck wallowing out the hole with a slightly smaller drill bit. However, this is by no means the proper or recommend method for enlarging the hole.

[EMG7895]

3/4" step bit?

[chevihemi]

3/4" step bit?
I am not sure if the step bit would work or not, being the part of the steering arm I am trying to drill out is 5/8" or so thick. Granted, you are only drilling the sides of the hole and not the hole itself. I might actually give that a try since I dont have a drill press or a lathe at my disposal.

[Wicked_S10]

Drill from the small side. Should be no issue. To get a good fit though, drill undersize, and ream to size.

[BigDusty]

x2 on the step bit

[PTSchram]

Drill from the small side. Should be no issue. To get a good fit though, drill undersize, and ream to size.

X2 This is the correct way to do this operation.

[SeaBass44]

arms are so cheap now, just buy new ones, stearing is pretty important, ranks up there with brakes:D

[Dookey]

arms are so cheap now, just buy new ones, stearing is pretty important, ranks up there with brakes:D

agreed. There are lots of areas where I don't compromise. It can't cost more that 20-30 bucks to have a machine shop do it properly. Money well spent for peace of mind.

[chevihemi]

I thought about just buying arms to use but I need to go with low-steer or the tie rod will interfere with the motor and frame rails. I have a couple extra arms so Im going to give it a shot on a spare and if I dont think it turned out well i'll find somewhere that can do it for me. I have already braced the final arms up very similarly to how 4rnrRick did his on his Sami build but I wanted to get rid of the TRE's and use heims instead.

Thanks for all the info!

[TheBandit]

arms are so cheap now, just buy new ones, stearing is pretty important, ranks up there with brakes:D

Since he is drilling a non-tappered hole that is larger than the large end of the current tappered hole, buying new arms really wouldn't be any different from drilling his current arms except someone else would be doing the drilling.

[SeaBass44]

Since he is drilling a non-tappered hole that is larger than the large end of the current tappered hole, buying new arms really wouldn't be any different from drilling his current arms except someone else would be doing the drilling.

he says the holes are boogered up, if he can't redrill then buying them already drilled for hiems is the way to go:smokin:

[ToddRH]

Drill from the small side. Should be no issue. To get a good fit though, drill undersize, and ream to size.

X3. This is the right way.

[maxyedor]

Drill from the small side. Should be no issue. To get a good fit though, drill undersize, and ream to size.

x4, did that on mine, but I took the arms off, drilled them in my drill-press and used a reamer to finish them, now the mounting points on my steering are the nicest thing on the truck:shaking:

[chevihemi]

he says the holes are boogered up, if he can't redrill then buying them already drilled for hiems is the way to go:smokin:
The one that I boogered up was the first (only one so far) that I tried to drill out to see how it would go...it didnt go well...LOL I have a pair left and an orphan one that I will try doing before the good ones I have all braced up already.

[Ed ke6bnl]

I'm probably stating the obvious, but of that size hole you need a good quality properly sharpened drill bit, relatively slow speed, and a very solid vice on a drill press or mill.

In fairly similiar situations I've had fairly good luck wallowing out the hole with a slightly smaller drill bit. However, this is by no means the proper or recommend method for enlarging the hole.


we did them on my boys 2000 ram 4x4 diesel. 3/4in. bought a new drill shipped $30 had some old drills and caused problem. slow speed and lube was not easy but worked out fine. they were on the truck too much to remove. Eed

[born loser]

We use a Harbor Freight bit from the set that comes in the wooden box. Ate through the hole in seconds w/ a little brake fluid to keep it cool/lubed. We drill them to 5/8" to do 'low-steer' using heims.
We've hogged through 5/8" steel with the same bits in sizes up to 1" w/ no problems at all and the bits are still sharp after dozens of holes.
Never would have thought HF would have come through w/ something decent.....lol

[chevihemi]

We use a Harbor Freight bit from the set that comes in the wooden box. Ate through the hole in seconds w/ a little brake fluid to keep it cool/lubed. We drill them to 5/8" to do 'low-steer' using heims.
We've hogged through 5/8" steel with the same bits in sizes up to 1" w/ no problems at all and the bits are still sharp after dozens of holes.
Never would have thought HF would have come through w/ something decent.....lol
are you talking the step bits or the regular drill bits they sell?

Thanks!

[Wicked_S10]

It sounds like the silver&deming bit sets they sell. Oddly, they are very good, actually excellent for the money. You can buy a whole set for the price of one large bit at a tool supplier, and if they dont break, they seem to stay as sharp, or better than big $ bits. I have two sets of them from HF, paid about $65 for 9/16"-1" by 32nds, and about $35 for 9/16"-1" by 16ths.

Step bits would be absolutely useless for this, you can drill thicker material then the step w/ a step bit, but unless your thickness is less than 2x the step, there is no way to get a even accurate hole. Step bits are excellent tools, but WTF? You can't use them for everything.

[Ed ke6bnl]

It sounds like the silver&deming bit sets they sell. Oddly, they are very good, actually excellent for the money. You can buy a whole set for the price of one large bit at a tool supplier, and if they dont break, they seem to stay as sharp, or better than big $ bits. I have two sets of them from HF, paid about $65 for 9/16"-1" by 32nds, and about $35 for 9/16"-1" by 16ths.

Step bits would be absolutely useless for this, you can drill thicker material then the step w/ a step bit, but unless your thickness is less than 2x the step, there is no way to get a even accurate hole. Step bits are excellent tools, but WTF? You can't use them for everything.


same thing those HF bits worked great for so many years int he wood box. BUt they did not have 3/4 for our purpose. One of HF good item surprises my and my boy every time we use them. Ed

[1TON73K5]

From the small side is correct BUT, If your going to actually drill it with a drill take the time to indicate it on center. A drill will flex and follow an exsisting hole so if it's off slightly you will have a slightly crooked hole. I would indicate it in, then use a smaller endmill to bore thru, then a reamer to cut to size. A endmill is stiff and wont flex near as much like a drill can and will. It would bottom cut and bore thru very easily and hold consintricity much better then a drill.

I understand you probably don't have a mill so I would use a multi flute 3/4 counter sink. There heat treated and stiff. As long as you center the hole with the spindle in your drill press by indicating it, a counter sink will self center better then a two flute drill and wont wollow around the hole edge before it starts to actually cut into the hole edge. Have you ever seen how a drill will cut a "hex" sometimes, instead of cutting with both lips at the same time it's flexing and bouncing around circularly as it's trying to drill thru, A counter sink will not do this.

[bgaidan]

It sounds like the silver&deming bit sets they sell. Oddly, they are very good, actually excellent for the money. You can buy a whole set for the price of one large bit at a tool supplier, and if they dont break, they seem to stay as sharp, or better than big $ bits. I have two sets of them from HF, paid about $65 for 9/16"-1" by 32nds, and about $35 for 9/16"-1" by 16ths.

Step bits would be absolutely useless for this, you can drill thicker material then the step w/ a step bit, but unless your thickness is less than 2x the step, there is no way to get a even accurate hole. Step bits are excellent tools, but WTF? You can't use them for everything.


Huh? Sounds like a theory. Looks good on paper, but I'm sure there are plenty of us here that have successfully drilled accurate holes through thicker stuff using step drills. I've done dozens through 1/2" and 5/8" steel and ended up with great tolerances.

[Wicked_S10]

Huh? Sounds like a theory. Looks good on paper, but I'm sure there are plenty of us here that have successfully drilled accurate holes through thicker stuff using step drills. I've done dozens through 1/2" and 5/8" steel and ended up with great tolerances.

Okay genius. Like I said, they will cut thicker material. If you cut thicker than the step though, and you don't cut from both sides, then you will end up with a hole with a step in it.

I don't know how you determine accurate, but I don't consider a stepped hole that is supposed to be a plain hole accurate at all. On paper or in person.

The only exception would be is you are drilling to the final step size, then there would be no step, but it also limits you to a handful of sizes.

I've done dozens through 1/2" and 5/8" steel and ended up with great tolerances.

How do you measure your tolerance? If it fits together, or if it looks good by eye, or even a tape measure, is not what I am talking about.

[chevihemi]

picked up both the step bit and Silver and Demming bits from HF. Broke the step bit off at the shank less than 1/8" into the arm. Used the Silver and Demming bits and was VERY impressed with them! A little cutting lube and they hogged right through. Thanks for all the help!!