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Chuck retaining screw for an older Jacobs 1/2" chuck?

Joined
Aug 14, 2023
Messages
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Location
Tennessee
Hello everyone,

I recently posted about my Wen All-Drill 950 1/2" electric drill. It's badged as a Penncraft, but the magic of Google Image Search revealed its true origins. I took it apart to do some cleaning and re-greasing, and discovered that the chuck retaining screw was missing.

If it's anything like the other drill I've worked on recently, it'll be a reverse thread. I took the drill into my local Ace Hardware, and asked for a reverse thread screw, and they looked at me like I had three heads. Back when I worked there, the more seasoned employees would have known exactly what I was talking about and whether or not they had such a thing, but I digress... They had reverse thread bolts, but they were too big for this application.

Attached are some photos of the chuck itself. Given the mass production that Wen was noted for, I doubt the chuck shaft is anything unique or proprietary.

The text on the end of the chuck looks like this: "=MC8K64=1/2-20 THREAD= CAPACITY 5/64-1/2="

Any assistance would be greatly appreciated. Other than this, there's no good reason not to use this drill and put it to work. After all, that's what it was made for.

IMG_20251007_083356.jpg

IMG_20251007_083408.jpg

IMG_20251007_083438.jpg
 
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RTM

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=MC8K64=1/2-20 THREAD= CAPACITY 5/64-1/2=
This part should give you clues. The 1/2-20 is pretty standard, so finding another drill with a 1/2-20 thread on spindle MIGHT have the same left hand thread screw to lock it on. Some parts diagrams give the size for “standard” stuff, you might get lucky, you might not.

You might find someone here who has time to take one apart and look also. I won’t see the inside of my garage for several weeks.

Example MKE 1001-1 drill, part #48, but it does not say the thread size on the chuck, so don’t take this as gospel. Also, in the chuck description, it describes left hand threads, but not on the screw.

 
Last edited:

Provincial

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I had a Craftsman reversing electric drill that had a similar mounting. If I remember right, the chuck and spindle were right-hand threads, and the retaining screw was left-hand threads.

This makes sense, as the forces on the chuck while drilling with normal drills would tend to tighten the chuck onto the spindle. Only in reverse would the chuck try to unscrew.
 
OP
W
Joined
Aug 14, 2023
Messages
23
Location
Tennessee
I had a Craftsman reversing electric drill that had a similar mounting. If I remember right, the chuck and spindle were right-hand threads, and the retaining screw was left-hand threads.

This makes sense, as the forces on the chuck while drilling with normal drills would tend to tighten the chuck onto the spindle. Only in reverse would the chuck try to unscrew.
I also have an older Craftsman 3/8" electric drill that's been knocking around here for 15 or 20 years after my brother pulled it out of a dumpster somewhere. It got wet in some flooding we had here recently, but still works. I took it apart to clean and regrease it. I think it ended up in the garbage because its chuck had become just loose enough to have the slightest wobble, but we didn't know then what we know now and thought something might have caused the shaft to get bent. I cleaned and tightened the chuck, and made sure the retaining screw was tight, and now it works great. I like that the motor brushes can be replaced, at least if you can actually find them.

But yeah, the chuck has a retaining screw that's reverse thread, and the chuck is threaded onto the shaft with regular threads. The Wen drill looks like it's the same setup only bigger.
 

The Cobbler

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very likely it's a standard LH thread. I would take a drill bit that fit the ID of the threads ( the minor OD) and see what that is. then go to the good old search engine & find what that measurement corresponds to. It is probably a fine thread .
I had to do this with a compressor head that I bought missing the LH threaded bolt that retained it. I found it was a 1/4-28 LH. had a very difficult time finding one... I figured out that a dewalt cordless drill had that size screw. Ordered one up & it fit the bill.
 
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genog

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... Other than this, there's no good reason not to use this drill and put it to work. After all, that's what it was made for.
(y)
Here Here!
You're right, there's absolutely NO reason NOT to put this ole boy back to work

Polishing old power tools like these to a mirror bright finish and putting them on display, makes me more than a tiny bit sad....
These ole boys should be used...

... I took the drill into my local Ace Hardware, and asked for a reverse thread screw, and they looked at me like I had three heads. Back when I worked there, the more seasoned employees would have known exactly what I was talking about and whether or not they had such a thing, but I digress...
:ROFLMAO:
Been there, done that myself

Have you been to an Auto Parts store lately?
I needed wiper blades and the clerk asked me what engine I had :ROFLMAO:
Please give me V-8 wiper blades!

I have a number of 1/2" Reversing drills with Jacobs chucks
different mfrs....Milwaukee, Porter Cable, Dayton, and Rockwell

All of them use similar if not the same reverse thread retaining screw...
Meaning that the screws will interchange, sometimes the screw head is taller and requires a deeper relief in the chuck, but they have the same reverse threads.

So......perhaps you can try checking with Jacobs?
See if they can point you in the right direction or simply send you a retaining screw
 
OP
W
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Messages
23
Location
Tennessee
So......perhaps you can try checking with Jacobs?
See if they can point you in the right direction or simply send you a retaining screw
Here is the response I received from Jacobs after filling out their contact form a few days ago:

Thanks for your message.

MC8K64 is Jacobs 1/2" Multi-Craft keyed chuck with ½-20 threaded mount.

Usually, it uses 1/4" or M6 retaining screw (left-hand). The retaining screw size was determined by Wen, not Jacobs. It was screwed on the drill spindle.
 

Beerhippie

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Far NE Oregon
(y)
...

Have you been to an Auto Parts store lately?
I needed wiper blades and the clerk asked me what engine I had :ROFLMAO:
Please give me V-8 wiper blades!

....
I recently needed a new drive belt for a frankentool in the shop. I took the old belt with me to the NAPA store.

"Make and Model?"

It's a forty-year-old shop-made shop tool. That's the make and model!

What happened to look up the number on the belt?
 
OP
W
Joined
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Messages
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Location
Tennessee
I recently needed a new drive belt for a frankentool in the shop. I took the old belt with me to the NAPA store.

"Make and Model?"

It's a forty-year-old shop-made shop tool. That's the make and model!

What happened to look up the number on the belt?
Many, many years ago, back when I was still a boy, I remember my grandaddy getting kind of irritated about how all the service and filling stations were turning into convenience stores. He said something like, "Forget getting any kind of help in a place like that. The people working in there are just programmed to take your money." Grandaddy was normally a pretty even-tempered person who didn't let things get to him, so for him to say something meant he was more than a little peeved.

Any kind of big chain store like a hardware or auto parts store has a computer that's supposed to tell the workers about everything they stock. Sometimes, it works that way. But if you get someone working there who relies too heavily on what the computer does or doesn't say, or simply doesn't care about what they're doing, you'll get someone who needs to know if your car's a V8 to sell wiper blades or can't be bothered to look at the part number on a belt.

I called Wen today to see if they had any additional insights about this drill and its screws, and while they were very polite and cordial on the phone, they had to tell me that they had no information at all about their older products. Guess the company got bought and sold a few times, maybe went bankrupt, and then someone much later bought the name so they could slap it on imported tools.
 

Beerhippie

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Joined
Oct 13, 2023
Messages
9,790
Location
Far NE Oregon
Many, many years ago, back when I was still a boy, I remember my grandaddy getting kind of irritated about how all the service and filling stations were turning into convenience stores. He said something like, "Forget getting any kind of help in a place like that. The people working in there are just programmed to take your money." Grandaddy was normally a pretty even-tempered person who didn't let things get to him, so for him to say something meant he was more than a little peeved.

Any kind of big chain store like a hardware or auto parts store has a computer that's supposed to tell the workers about everything they stock. Sometimes, it works that way. But if you get someone working there who relies too heavily on what the computer does or doesn't say, or simply doesn't care about what they're doing, you'll get someone who needs to know if your car's a V8 to sell wiper blades or can't be bothered to look at the part number on a belt.

I called Wen today to see if they had any additional insights about this drill and its screws, and while they were very polite and cordial on the phone, they had to tell me that they had no information at all about their older products. Guess the company got bought and sold a few times, maybe went bankrupt, and then someone much later bought the name so they could slap it on imported tools.

That's why I went to the local NAPA. Same old guy's been there since the ark landed and I thought he would be able to just go back to where the belts were in the stock room and grab the right one. Nope.

Back OT: Being Wen, and China, it's almost gotta be a metric screw. 6 X 1.5 left-hand?
 
OP
W
Joined
Aug 14, 2023
Messages
23
Location
Tennessee
Back OT: Being Wen, and China, it's almost gotta be a metric screw. 6 X 1.5 left-hand?
Remember, this is one of the vintage, US-made Wens from the late 60s, probably made in Chicagoland, so it's more likely to have a standard thread. I went ahead and ordered one each of the screws mentioned in previous replies. Also, I posted a previous reply where I included the response I received from Jacobs.
 
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