Flat Washer ID Help

[JoeLee]

I have a few flat washers I found in the shop that fit perfectly under the head of a 1/4" hex bolt without extending past the hex. Just what I'm looking for but I need more.

They measure .465 OD and .258 ID. I'm guessing that they are M6 which is pretty close. Am I correct ??

JL...........

[Doozer]

M6 is a good guess.
I like tight fitting washers.
Even SAE sometimes is a bit loose for my liking.
McMaster Carr has a good selection.

-D

[Hawkeye]

Look here, they list the ID and OD. https://www.boltdepot.com/Metric_fla...ted_steel.aspx
they also have SAE dimensions here:

https://www.boltdepot.com/Washers.aspx

[wierdscience]

Maybe these?

https://www.mcmaster.com/98687A111/

[ChazzC]

I often use metric washers for Imperial screws/bolts: like Doozer (ouch, that hurt to say) I prefer close-fitting ID’s and Imperial washers are too big to fit in standard counterbores - I wanted a washer to use under the head of a low profile 1/4-20 SHCS to secure my SMW fixture plate and chose these, which are perfect:

https://www.mcmaster.com/98691A116/

[luthor]

Possibly AN916-416 .

[BCRider]

At .258 for an ID those would be a super sloppy fit on an M6 screw. I'm pretty sure that they are proper 1/4's. And in fact they would be a touch sloppy on a 1/4. After all, 6mm is a bit smaller than 1/4.

The tag end of a box of 1/4 washers I've got here that I've been using up for about 20 years now measures .248 to .249 on my calipers. With a .463 to .464 OD. Depends on the burrs from the punching.

[Bented]

Shoulder screw shims.

[JoeLee]

At .258 for an ID those would be a super sloppy fit on an M6 screw. I'm pretty sure that they are proper 1/4's. And in fact they would be a touch sloppy on a 1/4. After all, 6mm is a bit smaller than 1/4.

The tag end of a box of 1/4 washers I've got here that I've been using up for about 20 years now measures .248 to .249 on my calipers. With a .463 to .464 OD. Depends on the burrs from the punching.

I never tried it on a 6mm screw. Just happened to find that it's a real nice fit on a 1/4" bolt and the OD doesn't protrude past the hex head.
I think the dimensions fall with in the tolerances of the M6.

JL............

[Doozer]

At .258 for an ID those would be a super sloppy fit on an M6 screw. I'm pretty sure that they are proper 1/4's. And in fact they would be a touch sloppy on a 1/4. After all, 6mm is a bit smaller than 1/4.

The tag end of a box of 1/4 washers I've got here that I've been using up for about 20 years now measures .248 to .249 on my calipers. With a .463 to .464 OD. Depends on the burrs from the punching.

Screws have a radius under the head where it transitions to the shank.
If they didn't, they would crack there in a New York minute once strain
was applied. You have to account for this radius with a washer sized
to clear it. So the minimum for a 1/4 washer is something like .260".
Seriously.

-Doozer

[BCRider]

Tell that to the maker's of my box of washers. I wish I could say what brand they are but the box with the name on it is long gone. I know a lot of my early stuff, and these certainly qualify, were Spaenaur. So odds are high that's the brand name.

You're right though. Other than the one size I measured the rest are all more like .260. And I can only use those smaller ones on certain bolts... Or the smaller 6mm stuff when I'm using metric. But when I bought them they were most certainly labeled as 1/4". I didn't buy metric stuff back at that time.

[JRouche]

I have a few flat washers I found in the shop that fit perfectly under the head of a 1/4" hex bolt without extending past the hex. Just what I'm looking for but I need more.

JL...........

I like them. A regular 1/4" hex head is small, metric probably fits right in there. I like a lil thicker washer thoe. A thin shim stock wont work. I like ground washers cause I am snobby. lol. No, I I. I like the shim idea, craze as it sounds. Other than that... I use ARP for flat washers and Cat (nice local facility) for all others when needed. Washer snob, maybe.. Engines need tight numbers see. JR

[JoeLee]

Tell that to the maker's of my box of washers. I wish I could say what brand they are but the box with the name on it is long gone. I know a lot of my early stuff, and these certainly qualify, were Spaenaur. So odds are high that's the brand name.

You're right though. Other than the one size I measured the rest are all more like .260. And I can only use those smaller ones on certain bolts... Or the smaller 6mm stuff when I'm using metric. But when I bought them they were most certainly labeled as 1/4". I didn't buy metric stuff back at that time.

The older hardware that I have is much cleaner looking as compared to some of this new garbage that you find in hardware stores. The older stuff was most likely all US made. Who knows where it comes from today. I've seen some real crap, stuff that I refused to even buy.

I've found that some metric washers fit real nice on SAE bolts and screws, but not all sizes. the 1/4" is probably an exception.

JL.............

[JoeLee]

I like them. A regular 1/4" hex head is small, metric probably fits right in there. I like a lil thicker washer thoe. A thin shim stock wont work. I like ground washers cause I am snobby. lol. No, I I. I like the shim idea, craze as it sounds. Other than that... I use ARP for flat washers and Cat (nice local facility) for all others when needed. Washer snob, maybe.. Engines need tight numbers see. JR

I like the thicker washers too. If you want real clean looking washers look at Jergens or TE-CO but those are really designed for hold downs etc. but I've used them in other applications.
I think those only come in standard sizes as their application is for the hold downs. I think they have metric sizes as well.

The CAT hardware is the nicest I've ever seen, but not cheap.

JL.............

[JRouche]

I like the thicker washers too. If you want real clean looking washers look at Jergens or TE-CO but those are really designed for hold downs etc. but I've used them in other applications.
I think those only come in standard sizes as their application is for the hold downs. I think they have metric sizes as well.

The CAT hardware is the nicest I've ever seen, but not cheap.

JL.............

Funny that you should say that, specially here (machinist land). I have looked at my large stash of hold down nuts and washers (they go together). for off usage. I could not, they cost more than a set of Cat nuts and washers.

Yeah, I got lucky. I am in the middle of a farm and all the industrial folks follow. Grainger was the first. Now we are up to a large CAT dealer and many others.

Get to know the front desk folks FYI. They really dont see that much traffic. And they are happy to accommodate. Took a tour through the entire wherehouse, or most of it. Best 40 minutes I invested in. Got to know the front office ladies, and good to buy CAT fasteners off the rack. Bring the bags to her and she would put it in the computer and tell me the cost.

Its like going to your best hardware store, with all the nuts and bolts in their place, X-100. No bins, just pallet sized shelves. I got lost .. Anyway, take care of your front office folks is all I meant.. You might learn something. JR