Bolt Motorcycle HardwareInc Aluminum/Copper Crush Washers 12X20 10 Pack

So far, I like these Bolt Motorcycle Hardware (DPWM12.20-10) M12 x 20mm Drain Plug Washer, (Pack of 10), but I am not using them for sealing up a drain plug on a bike, I suspect they would be good for that also. My use is for washers on my Super Capacitors, to assure good contact and conductivity for a start boost pack, like you find on Semi Tractors for cold weather starting and to help prolong battery life. Maxwell makes these Boost Packs and they are quite pricy, but my pack will be a lot less. These washers are the size of the threaded positive and negative ends of the caps and will seat tight, as they are soft and will make good contact for the high amps the pack will put out. Finally it will actually be a hybrid battery, with Lithium Ion batteries providing the 12vdc for the vehicle while the Caps will start the engine. Caps can be drained and charged a lifetime of use (Over 100,000 times as per the data sheet) so hopefully, it will be a keeper, even when changing vehicles. These are right sized washers and soft as well.

UPDATE: Almost 5000 miles since the oil change was done with these washers, during which I went on a 3100 mile trip touring Colorado. No leaking or seepage whatsoever. The Nomad has 2 drain plugs/crush washers, and both are just fine!!I ordered these for my Kawasaki Nomad 1700. Compared to the original factory washers, these are noticeably thinner and not as wide. Even so, the inside diameter was perfect and they appear to do the job. No leaks is what matters. The size comparisons, measured by a micrometer are: Bolt: Thickness 1.2mm; width of shoulder 3.9mm; overall outside width 20mm. The orginal factory washer is: Thickness 2.03mm; width of shoulder 5.09mm; overall outside width 22.4mm. As you can see, there is a substantial difference, thus my rating of a 4 vs. 5. I don't believe this will make a difference in actual use and will monitor these to confirm they don't leak. So far, so good.

Worked great.

These are the little washers you put on an oil drain plug (in my case an ATV) to prevent it from leaking. They are quite soft, so that they can seal better, but every so often should be changed to prevent leaks, or if you are a cheapskate like me, changed when you detect a drip. These work well, and at a good price.

Was supposed to be 10 Aluminum Drain Plug washers, but came as a BOLT brand kit with 5 aluminum and 5 copper washers. I'm OK with it as I can use both. Hopefully this was a mistake, but be aware. Bolt: DPWM12.20-10.

Works great whether you use either type. Great for the price. Used on Honda Rebel 500

I finally go to use these and they worked just fine on the honda fury.

The drain washers are very nicely made of aluminum which will crush and keep the oil in. But the shipping took over two weeks to get here, much too long for a simple envelop mailer.

I was upset that after paying more than I wanted to pay for sealing washers I didn't get what I ordered.I'm having trouble getting the copper sealing washers I already have to seal so I was told to get the aluminum ones, that they are softer and seal better. The pack cost over $15 and I received 5 Aluminum washers and 5 Copper washers. I hope these at least seal well.