Where can I get washers like this (pics)

[Rich Engelhardt]

I need some, only larger - both in size and in the size of the slot.
These are metric and the slot is 6mm - too small for 1/4" bolts.

I want to use them to make this jig:
https://www.youtube.com/watch?v=rPGa5QBQHmQ&t=96s

[Kent A Bathurst]

6mm is less than 1/64 shy of 1/4" File the slot wider? Or change to 6mm bolts?

Doesn't solve the length issue though. Hmmmm. How long does the slot need to be?

[Rich Engelhardt]

I did try smaller bolts. They are kind of a hassle though because the heads are so small. I have to use two washers on the heads so they fit inside the T-track the jig uses.

I did pick up some small files from Harbor Freight yesterday, but, that's going to be a lit of filing - the ones in the picture are just a tiny bit shy of 1/8" thick.
It would be nice if I could just machine a 1/4" slot - but - I don't have the equipment for that.

Since I only need 4 of them - I had thought about just picking up a sliding T-bevel for a couple bucks.

[Tom M King]

Maybe not long enough.

https://www.leevalley.com/en-us/shop/hardware/fasteners/washers/40940-expansion-washers

[Tom M King]

interesting how to ask google for such

https://www.7sportinggoods.com/product/3827903/oval-idler-washer/?origin=google_product_ads&gad=1&gclid=CjwKCAjwscGjBhAXEiwAswQqNCxs9O_MnmuoKKgWZFP5 _CvZLRdFnH_nITTLPdrajxwWXXwms2h__RoCbboQAvD_BwE

[Tom M King]

https://www.dieboard.com/products/die-hardware-accessories/rotary-diemaking-hardware/rotary-bolts-washers

[Bert McMahan]

Here's an alternate version of that jig that doesn't use those washers:

https://www.youtube.com/watch?v=vgXFszEf9Rc

[Chris Schoenthal]

I had to rack my brain to remember where I saw the one that I built. It's here (https://youtu.be/HNuW2_S-Avg?t=748) on the Hooked on Wood channel.
Extremely adjustable and easy to use and make.