Jacobs chuck key

[Coomba]

Maybe some one here can help me out.I just bought a used Jacobs 8 1/2 N drill Chuck at an estate sale, minus the key. I have tried most the major suppliers, for a key without any luck. What I need is an older style key, the newer ones do not fit correctly. The gearhead is either to small or to big. Does anyone know where I might be able to find an older style key?

 

[chucketn]

My info indicates a Jacobs key #K30 is what you need. Jacobs part # is 3664, with 5/16" pilot.

 

[Coomba]

The Jacobs # K30 will not fit the chuck. The gear head is to large. Apex Tool Group, now makes the Jacobs line and the keys they
make do not fit the older Jacobs chucks. At least for the 8 1/2 N. forgive me please if this post seems broken up. For some reason all the post are to the far right of my screen and I can not see the whole post.

 

[Geartooth]

Grainger's catalog lists their chuck keys along with a size description that could be useful to you.

https://www.grainger.com/category/c...keys&searchBar=true&searchRedirect=chuck+keys

 

[Coomba]

Grainger's catalog lists their chuck keys along with a size description that could be useful to you.

https://www.grainger.com/category/c...keys&searchBar=true&searchRedirect=chuck+keys

Thanks,but no help there.

 

[Mike1]

Your key No may be K30, but look at this stockist list it may help.
http://www.newmantools.com/jacobs.htm#suplink

Mike.

 

[Coomba]

I talked to the customers service rep. at the Apex Tool Group yesterday. They are the company that now manufactures, the Jacobs chucks. He told me, that when the Jacobs factory in Hardfort closed, they no longer continued to made a Chuck key for the 8 1/2 N. The new 8 1/2 N is different. That my only chance, was to find someone that has an older one for sale. Just my luck.:wall:

 

[Geartooth]

Can you tell us what size the pilot hole is on your chuck? Like me, I'm sure many of us have assortments of various unused chuck keys in their shops.

 

[bazmak]

Can you find one with a similar worm and adapt by bushing or turning down
the spindle.Shouldnt be too difficult see the amazing models people make
on this site Maybe a sketch and a couple main dims etc

 

[Coomba]

Can you tell us what size the pilot hole is on your chuck? Like me, I'm sure many of us have assortments of various unused chuck keys in their shops.

The pilot diameter is 15/64. I have turned down several keys hoping the gear head would fit, but came up empty.No body it seems is able to tell me the size of the gear head. My only chance is to find someone who has a lonely key sitting around in a drawer someplace. Problem still, most everyone thinks that the K30 key is the correct key, but it will not work.

 

[BaronJ]

A chunk of plasticine pressed into the teeth will provide you with the pitch details.

 

[Coomba]

A chunk of plasticine pressed into the teeth will provide you with the pitch details.

I'm not that accomplished of a machinist. I don't know what plasticine is, maybe an ideal of, what it might be. Would not know what to do with the information, if I did. Thank you, for your response, appreciated.

 

[Geartooth]

I know you don't have a chuck key to take measurements from. Since you have tried several, can you tell us what head diameter is too big or small or gear teeth too coarse or fine?
I'm sure this group can help you find what you want.

 

[Herbiev]

If you can give the diameter of the chuck and the number of teeth we can work out the pitch roughly.

 

[Coomba]

If you can give the diameter of the chuck and the number of teeth we can work out the pitch roughly.[/quote

Is it the diameter of the drill Chuck itself you want?

 

[chucketn]

I think Herbie is asking the diameter of the drill chuck itself, and the
# of teeth on the ring that the chuck key would engage. With that information one could calculate the pitch of the gear on it, and then figure out what size key you need.
Just out of curiosity, have you tried a 4-way key from Harbor Freight?
Chuck

 

[Coomba]

I think Herbie is asking the diameter of the drill chuck itself, and the
# of teeth on the ring that the chuck key would engage. With that information one could calculate the pitch of the gear on it, and then figure out what size key you need.
Just out of curiosity, have you tried a 4-way key from Harbor Freight?
Chuck

I was thinking that's what he meant after I gave it some thought. Might try to bring it down to Harbor Freight.

 

[Coomba]

I'll get that information, and let you know tomorrow.

 

[chucketn]

for what it's worth, I have a 1/2" drill chuck from Harbor Freight that came on a MT2 taper. The key pilot for it measures 15/64. A Letter B drill shank(.2380") fits the Chuck pilot hole. The Barrel of the chuck that has the mating teeth for the key measures 1.648" dia. and has 32 teeth. The Chuck key gear is .692" at the widest part, and has 12 teeth. It's the only chuck I have that takes that size key or I would send it to you to try. I'm sure HF would have something that will fit your chuck.

Chuck

 

[Coomba]

If you can give the diameter of the chuck and the number of teeth we can work out the pitch roughly.

The diameter of the chuck is 1.478, It has a small recess on the diameter where the teeth are on the chuck. It measures 1.434 at that diameter. There are 26 teeth. Thursday, I will be going into town, and will check the four way at Harbor Freight.