Reaming 101

I've got the reamer needed for the chevy 1ton TREs OTK. My question is: Is a tapered reamer made to move lots of metal, like a dril bit, or just make things round. I realize there has to be an initial hole for the reamer to do its thing. It's just that the only experience I've had with a reamer was when it didn't cut metal worth a shit. Maybe it was dull. Should I drill the hole first to the size of the smaller end of the taper? I'll be clamping the knuckle on a drill press so I'll have things nice and straight.

How have you guys done it on a drill press?

A reamer is meant to finish a hole, and there are "reaming allowances" for drilling a hole before reaming (I'd have to check my notes, but they're fairly small.)

Drill the hole to not quite the finished diameter of the small end, then finish the hole. Since you're using a tapered reamer, be careful that you don't carry it too far and screw up the hole!

Thats what I thought. Do you think that whats left after drilling the hole will be too much for the taper to handle?

lowrange2 said:

Thats what I thought. Do you think that whats left after drilling the hole will be too much for the taper to handle?

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Chuck your reamer in the drill press, keep it well lubricated (if you can manage nearly constant flow of light oil, you're OK...) and don't press too hard. Let the reamer work.

I've not used tapered reamers, but I've used straight reamers, and if you don't push them overmuch, they should do fine.

(Ideally, get a tapered drill to "pre-drill" the hole, but good luck finding one of those!)

Aight...thanks!

lowrange2 said:

Thats what I thought. Do you think that whats left after drilling the hole will be too much for the taper to handle?

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Depends on what size the drill is and what the taper is. [Don't know GM 1-Ton TRE's off hand] In general I don't like to remove much more than 3-4 thousands (.003-.004) with a reamer [or even a third of that for a precision reamer]. If you were complaining about your other reamer that "didn't cut metal worth a shit" this means that someone cut to much away, or tried to use it in the wrong direction. Both of those will kill a reamer in a hurry.

Edit: 5-90's got your best bet if you can't pre-drill the taper. Get as close to the minor diameter you can and work VERY slowy with lots of cutting/tapping fluid and you should be ok. Like he mentioned no force, let the reamer do the work, it could take awhile.

how slow is slow? Is gunna take way more than .003. The largest diameter of the TRE shank is .755 and the smallest is .688. So that means that I would have to remove .0335" of material.

Also this is the Snap-On Repairmans Reamer Stock No. R121 States: USed for enlarging holes from .5" to 1" - For use in any material. Not that that means anything but I thought maybe it was meant to move more metal.

lowrange2 said:

how slow is slow? Is gunna take way more than .003. The largest diameter of the TRE shank is .755 and the smallest is .688. So that means that I would have to remove .0335" of material.

Also this is the Snap-On Repairmans Reamer Stock No. R121 States: USed for enlarging holes from .5" to 1" - For use in any material. Not that that means anything but I thought maybe it was meant to move more metal.

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Well... slow in my book is about 1/3 a rotation (120 degrees) a second. Those are the models with serrations along the flutes, correct? If so, you should be fine using that reamer as it is not a precision style. Make sure you are square; hit it up with the 11/16" (.6875") drill first; take your time with the reamer using plenty of cutting fluid and you'll be fine.

Thats what I like to here! Thanks guys.

If you are reaming the knuckles for 1 ton steering, first drill the knuckles using a 5/8" bit I believe first. Then use the reamer slowly with cutting oil because it will ream the knuckles pretty quickly and you dont want to go too far. The pitman arm is the same process but takes much more time since its harder metal.

http://jcroffroad.com/install_guides/1tonsteering.pdf is helpful for 1ton installation.

djblade311 said:

If you are reaming the knuckles for 1 ton steering, first drill the knuckles using a 5/8" bit I believe first. ...

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I'd still use the 11/16" drill over the 5/8" drill. The closer you get to the diameter you want with a drill, the longer the life of your reamer. Being that any quality reamer isn't cheap, that's the route I'd take.

djblade311 said:

...you dont want to go too far...

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A good point. Rather than running the reamer in a ways, check it after every few turns (then every turn) as you get close to make sure you don't over do it.

lowrange2 said:

how slow is slow? Is gunna take way more than .003. The largest diameter of the TRE shank is .755 and the smallest is .688. So that means that I would have to remove .0335" of material.

Also this is the Snap-On Repairmans Reamer Stock No. R121 States: USed for enlarging holes from .5" to 1" - For use in any material. Not that that means anything but I thought maybe it was meant to move more metal.

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What speeds on your drill press? You typically figure tool speed as (4CS)/D, where "CS" is the cutting speed of the material (for iron/mild steel, about 100ipm) and "D" is the diameter of the tool (use the largest diameter for tapered tools or for "form-cutting" tools like edge rounders and ball mills.) This gives you your speed in RPM.

So, you'd run a drill for the largest diameter at (4x100)/.755, or 400/.755, or ~530rpm.

Reamers don't run anywhere near as fast as drills - try to reduce speed for a reamer by half. So, around 250-300rpm should work neatly for you. Light pressure on the feed handle, and (as I'd said before,) try to keep as close to a constant flow of light oil over the work as possible. If you heat up a reamer, it's toast. Try to maintain a consistent chip - too little pressure, and you're not cutting (you're going to be literally rubbing material off.) Too much, and you burn up your reamer. However, you can always press a little harder to make it work, so start out light. I'm assuming you're drilling/reaming a cast knuckle, which should give you a "grainy" chip - you're going to get more of "large particles" from cast iron/steel than anything else.

It also won't hurt to back out the reamer and flush the flutes out fairly often, so you don't get "chip weld" causing you trouble (shouldn't be a problem if you keep the coolant/lubricant going, but it can't hurt.) A light cutting oil, light machine oil, or transmission fluid should serve you well as a coolant/lubricant.

I have a 500rpm setting on my drill press. It should work ok. I gotta pick up a drill bit tomorrow.

ur still going to sell it to when ur done with it right lol

lowrange2 said:

I have a 500rpm setting on my drill press. It should work ok. I gotta pick up a drill bit tomorrow.

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That's as low as you can go? It should work for the drill, but be careful with the reamer...

lowrange2 said:

how slow is slow? Is gunna take way more than .003. The largest diameter of the TRE shank is .755 and the smallest is .688. So that means that I would have to remove .0335" of material.

Also this is the Snap-On Repairmans Reamer Stock No. R121 States: USed for enlarging holes from .5" to 1" - For use in any material. Not that that means anything but I thought maybe it was meant to move more metal.

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got me one of those (I think that's the snapon part number at least). Anyways, it lasts through about 3 holes I drilled only the outer opening to 5/8" for the threaded part of the TRE and reamed the rest. Last hole was done on its last legs...

OH yeah, I used plenty cutting oil and used my air ratchet to move things along.

Kejtar said:

got me one of those (I think that's the snapon part number at least). Anyways, it lasts through about 3 holes I drilled only the outer opening to 5/8" for the threaded part of the TRE and reamed the rest. Last hole was done on its last legs...

OH yeah, I used plenty cutting oil and used my air ratchet to move things along.

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Well.......I might not want to buy it after your done........

5-90 said:

That's as low as you can go? It should work for the drill, but be careful with the reamer...

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no it'll go all the way down to 50rpm

C85D4x4 said:

ur still going to sell it to when ur done with it right lol

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I wouldnt shit ya... If it's dull I'll let ya know. If it's still cuttin good you're very welcome to it.

I've seen guys kill a couple of knuckles in the same day really fast by not checking the hole every turn or two (hi cracker!), and make sure you check with the end that goes into the hole - the taper while the same angle isnt the same size for all of the ends you are likely to be using.

And do not press hard as stated and FOR THE LOVE OF GOD USE GOOD CUTTING FLUID. I have killed a couple of reamers, one borrowed (hi josh!) by either pressing too hard, using shitty fluid or spinning too fast. Getting the pitman arm into a drill press will help a lot. Keep one steady angle as you ream. I have one hole that I started, and while I was taking a break someone else finished. We held the drill different ways and its slightly 'egged' now. its egged at an angle opposite to the forces it usually sees, so it hasnt been a real problem .. but *I* know its there.

Just take your time.

lowrange2 said:

no it'll go all the way down to 50rpm

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You don't need to go all the way down to 50 - but if you can get down around 300rpm or so, it will be better on you than 500...