Re: 3/8" drill chuck replacement

Joe Gwinn <joegwinn@comcast.net> wrote:

On Thu, 10 Apr 2025 23:38:37 -0000 (UTC), bp@www.zefox.net wrote:
 

Joe Gwinn <joegwinn@comcast.net> wrote:

On Wed, 9 Apr 2025 23:31:08 -0000 (UTC), bp@www.zefox.net wrote:
 

Leon Fisk <lfiskgr@gmail.invalid> wrote:

On Wed, 9 Apr 2025 00:48:13 -0000 (UTC)
bp@www.zefox.net wrote:
 
<snip>

Does anybody have a favorite, or suggestions to avoid? It's
a normal 3/8-24 right hand female thread, so that's easy. The
original chuck is Jacobs, are there better brands out there?

 
I put a Jacobs that looks like this one on my battery drill several
years ago. I don't use it a lot but it works really well for me. I like
it better than the keyless chuck that came on the Dewalt 3/8 inch corded
drill. It clicks down when you tighten it. Price is similar to what I
paid (~$20) over 5 years ago at a local Menards store. They don't seem
to have it anymore...
 
https://www.amazon.com/Jacobs-30354-8-Inch-Keyless-Spindle/dp/B00002N7TK/
 

>
Thanks for the tip. The price seems surprisingly low. Added to my list
if things needed to make a free shipping order.

 
Bob, I'd read the one-star reviews first.

>
Point taken. I usually check bad reviews but didn't this time. the
"wrong thread" complaints are quite surprising.

 
This was usually when they tried to buy a chuck that fit named kind of
drill.  There may have been wrong-item-shipped problems.
 
The key comment is that the new chucks are imprecisely made, and so
the chuck cannot grip firmly no matter what you do.
 
Llambrich makes very good chucks.  Their JK Industrial line seems most
suitable. About USD 200.
 
.<https://llambrichusa.com/keyless-chucks/>
 

Interesting that the page is footnoted "Quality made in Spain"
They do look nice, but rather an overkill for a hand drill.
 

Röhm is also very good.

Again, 1-star reviews are not encouraging, prompt breakage

 
 
These hand-tightening chucks will all open if rotated in reverse. Does
this matter?

 Usually, no. In some cases yes. Best to avoid, I think.

 

Still, in-person transactions aren't foolproof, at least when I'm the
fool. Went to a local Ace store and asked for a chuck key to fit a
3/8" Jacobs chuck with a 15/64ths (0.234") pilot. The pilot's right,
fits just fine. but the pinion gear is too big.

 
Yeah, chuck keys have two parameters, not just one.
 
.<http://www.jacobschuck.com/uploads/202206/14/220614010822483.pdf>

 
The table makes me scratch my head. The key I have which seems to fit
is a 15/64" pilot with 11 teeth on a 1/2" pinion, from a 1/4" Makita drill.
Not in the table, far as I can tell.

The key I mistakenly bought has a 15/64" pilot with 10 teeth on a
roughly 0.665" pinion. 30825, but with a D suffix.

Looks like maybe I need a "gotcha" key. I'll take the chuck with me
when trying to exchange the key I bought by mistake.

Thanks for writing!

bob prohaska