Drill couplings

This is pretty obslete and random but can anyone tell me a good source to get the drill motor couplers we used last year?(remember the black things)
thank you

You mean LoveJoy couplings? If so, you can order them through LoveJoy. Not sure if SPI has them.


We have at least one if you’d like to work some sort of deal.

As I recall, these where just standard rigid couplings from Ruland or others with one end tapped for the drill thread.

It is easily obtained by going to McMaster.com. You will have them on your dock tomorrow if you order by 5:00pm EST - with no extra shipping or any rush put on the order at all (at least that is how it works for me here near Detroit – the orders are filled from Ohio for me. As usual, your mileage may vary).

PM me if you have difficulty finding the part.

Joe J.

P.S From McMaster:


One-Piece Clamp-On Coupling Steel, W/O Keyway, 1/4" X 3/8" Bore, 7/8" OD
$ 18.16 Each

You will have to open up the 1/4" side to be the right size for the tap you need (3/8-24? – can’t recall for sure). Good Luck…

For this season’s drill motors, you’d need to open it up and use a 1/2-16 tap.

You may have to order that tap, as well, as it’s non-standard.

I am quite certain that the thread on OD of the 1/2 inch drill we have in the kit this year is 1/2 - 20 (not 1/2-16 as stated above).

If you want to use a similar coupling to last year’s with this year’s drill shaft, I recommend using the following coupling:


One-Piece Clamp-On Coupling Steel, W/O Keyway, 3/8" X 1/2" Bore, 1-1/8" OD
$ 20.76 Each

This will allow you to open the hole on the 3/8 side to the appropriate diameter for the 1/2-20 tap. My machinery’s handbook has the hole size as 29/64 (.4531").

The tap is a National Fine (NF) tap so it may be a bit rarer than usual. McMaster has them though:


High Speed Steel Hand Tap Bright Finish, Plug, 1/2"-20, 3 Flute
$ 11.41 Each

Good Luck,

Joe J.

I really like the flexible LoveJoy couplings. We sued these couplings for a while, and then found out that they didnt hack it. Plus the lovejoys will let you have some misalignment/wobble without punishing you for it


*Originally posted by Joe Johnson *
**I am quite certain that the thread on OD of the 1/2 inch drill we have in the kit this year is 1/2 - 20 (not 1/2-16 as stated above).

Joe, are you super-duper-absolutely-without-a-doubt certain about this?

I ask for two reasons. . . first, and most importantly, I specified 1/2-16 in my drawings for a shaft coupling. Our machinist did a cursory analysis of the shaft output, too, because he didn’t believe me, and agreed it was 1/2-16.

I took that information, perhaps erroneously, from FIRST’s provided Virtual Kit of Parts. On the drill motor model provided for Inventor, the thread was 1/2-16.

Did Autodesk mess something up?

Edit: I just double checked, and the Autodesk model definitely reads 1/2-16. I understand it’s easy for someone to slip on something like that, though. The search continues.

Edit #2: According to the model of the drill coupling, it’s a 1/2-20, like Joe said. Grr. I should’ve double checked this. Autodesk should have, too. Thanks for bringing that to my attention, Joe. A lot. You could have just saved the day.

1/2-20 is the thread.

I have checked it out in several ways:

1/2" chucks are only available in 1/2-20 thread

I have threaded a nut on it that is out of a box marked “1/2-20”

I have held up a bolt that I measured to be 20 threads per inch to the drill shaft and matched up the threads perfectly.

Finally, I measured the thread length of the drill shaft (~3/8") and counted the number of threads (~7.5) to get (60/3 = 20).

Believe me or do your own measurements & calculations but you can depend on it, the thread is a 1/2-20.

Joe J.

Yep yep. You’re absolutely correct. :slight_smile:

Luckily, our machinist caught the error and made the appropriate changes.

Again, thanks for the correction, Joe. …that’ll be the last time I rely on the Inventor models for important data.