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Tool Which ER32 UM Wrench?

Tool

Felis

Member
Gents,

I am needing to buy an er32 collet chuck wrench.

I see them available in single tooth, 4 tooth, and an annular version with 6 teeth.

Is one version better than the other?
The single tooth version seems to be common. Will it gall the chuck nut when torquing to spec?

That brings me to er32 nut torque. My research indicates that for mill use and tool holding, torque should be 100 ft lbs.
For lathe use and work holding, much less torque is ok. Around 30 to 35 ft lbs.

I will doing the latter.

Which wrench do you prefer, and how much torque do you use for your application?

Thanks for your thoughts.
 

Tom Kitta

Ultra Member
I use single tooth. After few thousand not on and nut off cycles I have yet to destroy single nut. So I think you be fine as well.

For general milling / drilling I snug the ER32 with one hand on the break and one on the nut with most of my strength. For something harder I use all strength. If it is special application, like say large tap in ER not an EM I can use the hammer to add extra grip power.
I may also add extra grip power when say using a dull EM and taking heavy cuts with it anyways - the danger here is EM pulling out of the ER32 collet. Spinning inside of the collet is very rare - only say with a tap (either intentional or not torqued enough).

For lathe work with holding work in ER I so far did not use a hammer and never had part spin. Again for tapping application I may tighten more with a hammer.
 

phaxtris

(Ryan)
Premium Member
Premium Member
I do the same as Tom, one hand on the nut wrench and one on the ?body? Wrench, put them on 90 apart and a good shove...no torque wrench

If I was doing something critical and worried about it pulling out, a couple mild raps on the nut wrench


I wouldn't worry about galling the nut, you'll more likely ruin the wrench before it wrecks that little slot...and there are what 6? Slots to ruin before the nut is ruined

Food for thought, iron workers use that same wrench/nut with a slot setup for the hole punch dies, a lot of guys literally hammer on the wrench with a 3lb hammer every time they change the top die...I have yet to see a nut wrecked beyond use.....now it's totally unnecessary...but it's what a seems to happen and they last....not recommended
 

YotaBota

Mike
Premium Member
a lot of guys literally hammer on the wrench with a 3lb hammer
There's a video out there somewhere of a guy using a BFH on a single tooth wrench tightening an L type chuck.

What machine are you working with? I have an ER40 chuck on the lathe and have not had any issues using the single tooth wrench. I snug up the nut and then give the wrench a couple of taps by hand and haven't had any issues (yet). I made a wrench to fit the chuck and the nut but by putting the lathe in low gear and tightening the nut by hand I find the chuck wrench isn't needed.

Buy,,,,,, what be this buy you speak of? lol My chuck came with a 54mm-62mm wrench that didn't fit the chuck to my liking so I made mine. A bit sawing here and filing there and it was done. Oh, and a bit of rotary table work for the arcs.
P1010842.JPG
Edit - 55mm-62mm wrench
 
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100 ft lbs sounds about right.

During my time running 15hp VMC’s, we used the 4 tooth type wrench and a bench mounted fixture to hold the BT40 toolholder keys. The standard wrench length is designed for tightening the nut using an average person’s strength to give a good pull… NO MORE. This is usually enough, there were a few rare occasions that a cutter did pull out, but that was a 3/4” high helix taking a full depth 2.5”x .015” finish cut on a pocket wall in 4140 steel; had really bad harmonic chatter (squeel) that cause the cutter to pull out.

However, if OVER tightened, it can actually crack the taper of the ER toolholder. On several occasions we couldn’t figure out why the cutter TIR was suddenly over .010”, upon closer examination we found a hairline crack in the taper of the holder; and these were good brand-name tools….
 
I use a 4 tooth one which one of my better suppliers that supplies production shops suggested. Personally I think it just matters on how coordinated you are in using the tools. More teeth allows for lower concentration or coordination. In production shops while the skill is there the need for performance under time constraint is also a factor which I suspect influence the choice.
 

Dusty

(Bill)
Premium Member
Gents,

I am needing to buy an er32 collet chuck wrench.

I see them available in single tooth, 4 tooth, and an annular version with 6 teeth.

Is one version better than the other?
The single tooth version seems to be common. Will it gall the chuck nut when torquing to spec?

That brings me to er32 nut torque. My research indicates that for mill use and tool holding, torque should be 100 ft lbs.
For lathe use and work holding, much less torque is ok. Around 30 to 35 ft lbs.

I will doing the latter.

Which wrench do you prefer, and how much torque do you use for your application?

Thanks for your thoughts.

@Felis for what it's worth I use the ER32 collet wrench available from accusizetools.com page 29 of their catalog, item #0532-K032 at $12.00.

For my money they are a well made single tooth wrench, soft grip handle fits nicely in the hand,. Actually I have 2 of them one stationed at my hobby mill and one for my lathe.

210 mm long x 5 mm thick

open the catalog from here check it out www.accusizetools.com
 

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VicHobbyGuy

Ultra Member
@Felis - If you are nearby - I live in Victoria Fairfield- you can borrow my 'ring' style wrench for a few days to give it a try. I don't use it much, but I plan to keep it in case the 'one tooth' decides to hide on me some day. some of my tools have started doing that! :)
 

Felis

Member
@Felis - I believe ER32 uses a 55mm wrench, if you want the one I have it's yours. The picture shows the fit on the ER40 nut so it should be good on the ER32.
View attachment 24502
I'm about ten minutes west of Sooke so it may be cheaper to buy one than pay the gas to get out here. Anyway, the offer is there, your call.
Thank you Mike. I would be happy to accept your kind offer. I’ll send a pm your way.
 

Felis

Member
Thank you gents for your advice and help. Much appreciated

I had just purchased an Eccentric Engineering er32 chuck, for a myford lathe. Gary, the owner had the same advice as you have said, a single tooth wrench will work just fine.

Now I am not sure if the chuck nut that Gary makes has the same thread count / pitch as all other er32 chuck nuts, thus, me not wanting to damage it.
 
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