Why Doesn't Demco Cast Head Coupler w/ Jack Hole # DM37ZR Come with Hardware

Updated 06/15/2026 | Published 06/10/2026

Question:

What type and size of bolts/nuts/washers are needed for installing the DM37ZR? We never received a package of bolts or anything else.

asked by: DOUG O

Expert Reply:

Hey Doug, the Demco Cast Head Coupler w/ Jack Hole # DM37ZR that you referenced doesn't come with hardware as not every application will be exact same and it's best to go with what makes the most sense for your trailer. Usually Grade 8 nuts and bolts with washers are used in an appropriate size. Or you could have the coupler welded on as well.

expert reply by: Jameson C

Installed Coupler
(click to enlarge)

Richard L.

6/12/2026

I used grade 8 bolts and nuts didn’t bother to weld it won’t need too it’s not going anywhere but I wish they made the jack stand 1” farther back now my tailgate hits it.

Tony

6/12/2026

I used grade 8 bolts and nuts. Mine was a difficult reach to some of the nuts to get them tight. I had to do a lot of cutting and grinding to get it to fit as my old one was welded on and was a very old model no longer available. The one works fine.

Jameson C.

6/15/2026

@RichardL makes sense! Thanks for sharing that!

The G.

6/13/2026

I used 1/2"-13 Grade 8 bolts, Nylok nuts and washers. I had to grind some old parts off first and the clamp the coupler in place to drill the holes. It fit perfectly and is really a nice part.