DOM tubing

[gilbertson]

Hello

I bought some DOM tubing to make new hinges for my backhoe. I ordered 1.5 od and 1 id, came in at 1.055 id. It is a sloppy fit. I had thought the size should be closer than .055. Question is should I send it back or install a shim? I was thinking shim stock could work as a wear bar and be replaceable. I am going to install grease filltings also.

Thanks

Vern

 

[tulenutn2o]

DOM generally holds the tighter tolerance on the wall thickness. And wall thickness can be specified. Any of the major steel suppliers web sites can give you all the specs and you can use these specs to order from your steel supplier. All those bookmarks are on my cadd computer.By the way, .005" for a hinge that should be greased, doesn't seem too sloppy to me. What fit are you shooting for?

 

[gilbertson]

Spoke to Metal Depot this morning, DOM ID tolerance is .008, they are sending a replacement and picking the other up. Good company to deal with, a little expensive on shipping but.....

 

[gould37]

The more I work with tubing, the more I realize that there are no two pieces the same. Maybe close, but not the same. I know they say the tolerances are suppose to be close, but if I order 200' of tubing and mic it when I get it, the wall thickness and size varies. Like it was said, I don't think the clearance you have is too great. Remember to leave a little room for flex, dirt and corrosion. If it is too tight now, chances are it will only get worse.

 

[gilbertson]

I know it cannot be tight but was thinking .010 to .015 would be acceptable and still allow for grease.

thanks

 

[om21braz]

About 20 years ago, you could have got straighter, closer tolerance, "better" steel. Seems nowadays you have to be a large quantity buyer requiring mil-spec grade material to get good steel products on a regular basis. We've sent material back only to get something worse in return.

 

[dfkrug]

I know it cannot be tight but was thinking .010 to .015 would be acceptable and still allow for grease.

.010-.012 is ideal for a greasable bearing, IMO. .005 is too tight.

I have bought DOM numerous times and I have never seen it off by more
than a thousanth or two. Both for .750" ID, and for 1.000" ID.

 

[JRP]

For those of use new to this, what is DOM?

 

[MikeD74T]

Drawn over mandrel -smooth inside with no seam & consistant dimension. Most tubing is rolled/folded from flat stock into shape & welded. DOM is an additional process, a mandel is pulled thru the tube, that forms/smooths the interior of the tube. MikeD74T

 

[dfkrug]

Spoke to Metal Depot this morning, DOM ID tolerance is .008, they are sending a replacement and picking the other up....

I did not know about that tolerance. Next time I buy some, I will be extra
careful.

Here is an update on my samples. I have DOM stock from 3 batches, and
they are all undersized, 2 are -.001, and one is -.003. The 3rd was
a surprise. This is not bad news as I use 25mm pins to get the right
clearance.