best drill bits??

[RWebb]

cobalt??

or Ti (which are just coated, I'm sure)

or???

this is all about drilling the center out of a damn roll pin.... maybe it's hardened

[URY914]

Roll pins are a PITA to drill out. Go slow and use cutting oil. You'll eat up several bits no matter what they are.

[Tim Hancock]

Originally Posted by URY914

Roll pins are a PITA to drill out. Go slow and use cutting oil. You'll eat up several bits no matter what they are.

Yep Yep

[masraum]

Again, what's a decent bit to buy. I've wondered this a bunch of times. I see lots of "coated with this" and "coated with that", and figure that some of that is just marketing hype. I'd like to buy a nice set of multipurpose bits, and possibly a decent set of occasional use metal bits. I don't drill metal often. When I do it's usually sheet metal and that sort of thing.

[vash]

ROLL PIN drilling is torture. you need to start with a small enough bit. the bit will bite into the irregular "hole" formed by the rolled material, and snap it. repeat a few times, toss part into yard, kick part...hurt toe, feel dumb. (i've heard)

[Porsche_monkey]

Solid carbide bits. Not cheap.

[126coupe]

My snap-on bits are pretty good, but$$$

[MattKellett]

For everyday drilling I would recommend just plain old High Speed Steel (HSS). You can sharpen them and they don't chip as easily as carbide.

[slodave]

Broke about 5 Ti bits drilling out my roll pin...

[TimT]

try left handed bits

[RWebb]

HSS is good for wood IMHO, but not so good for steel.

Vash - I used a Dremel grinding bit to "initiate" the hole - works great for that and the cone shape creates a nice funnel shaped entry. But they can only go so deep... and the deeper they are, the more likely they are to break...

I bought the Rigid cobalt bits. Home Despot also have Ti coated, and something else. The other two brands were DeWalt and Bosch or another good brand name. As usual, the sales clerk knew nothing at all about his wares. OTOH, I paid nothing at all either. My credit card points can be transmogrified into HD gift cards so I used that. The Rigid bits came in a nice case and the whole thing was clearance saled down to $20.

They worked - I put in another hour drilling and none of the bits broke off. I was then able to...

Drive Out the Spawn of Satan.

But, with the roll pin out, I now need to be able to get the freakin' clutch lever off the shaft (the pedal cluster). I do not own a puller and my brass hammer has been ineffective in driving the shaft out the other way. Maybe the freakin' thing is not supposed to go out that way??

I am not clear on how a left handed bit would help with a roll pin???

[Pazuzu]

What about a step bit (Unibit)? They're mighty strong.

[Tim Hancock]

Originally Posted by RWebb

HSS is good for wood IMHO, but not so good for steel.

Vash - I used a Dremel grinding bit to "initiate" the hole - works great for that and the cone shape creates a nice funnel shaped entry. But they can only go so deep... and the deeper they are, the more likely they are to break...

I bought the Rigid cobalt bits. Home Despot also have Ti coated, and something else. The other two brands were DeWalt and Bosch or another good brand name. As usual, the sales clerk knew nothing at all about his wares. OTOH, I paid nothing at all either. My credit card points can be transmogrified into HD gift cards so I used that. The Rigid bits came in a nice case and the whole thing was clearance saled down to $20.

They worked - I put in another hour drilling and none of the bits broke off. I was then able to...

Drive Out the Spawn of Satan.

But, with the roll pin out, I now need to be able to get the freakin' clutch lever off the shaft (the pedal cluster). I do not own a puller and my brass hammer has been ineffective in driving the shaft out the other way. Maybe the freakin' thing is not supposed to go out that way??

I am not clear on how a left handed bit would help with a roll pin???

In the machining department where I work, all they stock is high speed steel drill bits for machining metal and my 3 sets of drill bits (fractional, letter and number) at home are all HSS. I use them for metal all the time. Sometimes I snap one and replace it, but usually I just resharpen them on the bench grinder if they get chipped or dull.

I do have one set of cobalt drills that I have used a couple times in ten years when trying to drill hard stainless.

When I rebuilt my pedal cluster, I used a punch and a big effing ball peen hammer to beat the effing roll pin out. In regard to your clutch lever/shaft.... You need a bigger hammer and a beefy brass punch..... HIT THAT SUMBEOTCH!!!!

[john walker's workshop]

an air hammer gets them right out and does the shaft too.

[RWebb]

Thx - I have no air tools at all.

No place in town carries brass drifts - already wasted days looking for one.

[TerryH]

roll pins are hollow with a collapsible slot, dowel pins are solid.

to remove a stuck dowel pin, freeze the pin and heat the surroundings

[Superman]

One very important principle to remember is the amount of force applied to the pin. WE usually fail to get enough force on it. Take for example the roll pins in Bilstein struts. You can bang a drift against that pin all day long with a full sized sledge hammer and not move it. Or you can drive it out with a medium ball pein hammer. The trick is to get the strut itself to not move. There is plenty of flex in the strut, so the pin will not feel the trauma of the hammer unless some sort of anvil-thing is held to the back of the strut.

Same with the old-fashioned method of releasing tapered shafts from tie rod ends. Whack them HARD with a steel hammer. It goes way easier if you hold another hammer against the back of the tie rod end.

[Chas White]

The thing with drill bits... if they're not cutting, they're burning. Lots of times its hard to put enough pressure on a hand drill.

[VaSteve]

Originally Posted by RWebb

Thx - I have no air tools at all.

No place in town carries brass drifts - already wasted days looking for one.

I went to Lowe's and got a set of punches. They are blue Dasco Pro brand. I knocked out my pedal cluster roll pin no problem. I used them on the Bilstein and it was a little more effort. They are not brass, something harder but I'm not sure what. The mistake I originally made with the Bilsteins was not using the right size punch. They are tapered, so I though the pin went into the hole in the pin and the shoulders/taper rested on the outside edge. That has an amazing effect of mushrooming the roll pin. So did an air hammer my friend (a pro mechanic) used on his pedal cluster.

[Zeke]

Originally Posted by TerryH

to remove a stuck dowel pin, freeze the pin and heat the surroundings

Hard to do when assembled. I think that's more of an assembly trick.

Randy, I would be my opinion that if you buy industrial bits from someone like McMaster Carr that you will get good merchandise. I have had two boxes of indexed bits for nearly 40 years. The softer ones get resharpend and replaced as needed. Many are original. The brittle ones will snap and I use them carefully when the going gets tough, like stainless. I don't know exactly what they are, so when one goes away, that slot becomes vacant.

But they ain't newfangled.